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Neurolathyrism

Definition

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Causative Agent / Neurotoxin

• BOAA over-stimulates AMPA glutamate receptors
• Leads to increased intracellular reactive oxygen species (ROS)
• Impairs mitochondrial oxidative phosphorylation
• Causes selective degeneration of Betz cells in the motor cortex and the longest corticospinal tracts subserving lower-limb function
• Anterior horn cells are spared

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Epidemiology (Community Medicine Perspective)

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Clinical Features

• Pain, paresthesias (formications/tingling), and weakness in the lower extremities
• Progressive spastic paraplegia (bilateral)
• Leg cramps and spasms
• Bladder dysfunction — frequency, urgency, sphincteric spasms
• Erectile dysfunction
• Occasional coarse tremor of upper extremities

• Predominantly upper motor neuron signs (spasticity, hyperreflexia, extensor plantar response)
• Sensation is usually preserved (though some historical cases reported sensory loss)
• Once established, the disorder is irreversible but non-progressive (unless exposure continues)
• Lifespan is not affected

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Neuropathology

• Degeneration of corticospinal tracts and posterior columns in the spinal cord
• Loss of myelinated fibers in lateral and posterior columns
• Loss of large Betz cells in motor cortex
• Anterior horn cells are unaffected (distinguishing from ALS/polio)
• Gliosis and thickening of blood vessel walls in degenerated tracts

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Prevention (Community Medicine Focus)

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Differential Diagnosis

• Konzo (cyanide toxicity from cassava — similar UMN picture)
• Tropical spastic paraparesis (HTLV-I)
• Hereditary spastic paraplegia
• Primary lateral sclerosis
• Spinal cord compression

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Key Points for Exams

• Cause: BOAA toxin in Lathyrus sativus (grass pea / khesari dal)
• Mechanism: Excitotoxicity via AMPA receptor over-activation
• Pathology: Upper motor neuron disease; Betz cells degenerate; anterior horn cells spared
• Features: Irreversible spastic paraplegia, no sensory loss typically, non-progressive
• Occurs during famines/droughts — a classic community medicine/public health topic
• Prevention: Dietary diversification, detoxification of peas before consumption

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Natural History of Disease

(As per K. Park — Preventive & Social Medicine)

Definition

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Two Periods in Natural History of Disease

1. Pre-pathogenesis Period

• The ecological triad (Agent – Host – Environment) is in equilibrium or being disturbed
• The host is susceptible but not yet diseased
• The appropriate intervention here is Primary Prevention

2. Pathogenesis Period

a) Early Pathogenesis (Sub-clinical / Pre-symptomatic)

• Biological/pathological changes are occurring
• No signs or symptoms yet detectable clinically
• May be detectable by screening tests
• Appropriate intervention: Secondary Prevention (early diagnosis and treatment)

b) Late Pathogenesis (Clinical Disease)

• Symptoms and signs become manifest
• Can progress to:
  • Recovery
  • Disability
  • Death

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Leavell & Clark's Model: Levels of Prevention

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Primary Prevention

• Health education
• Adequate nutrition
• Provision of adequate housing, recreation, working conditions
• Marriage counselling and sex education
• Attention to personality development
• Genetic counselling

• Immunisation against specific diseases
• Use of specific nutrients (e.g. iodine in salt for goitre)
• Protection from occupational hazards
• Protection from accidents
• Use of specific nutrients (vitamins)
• Environmental sanitation
• Protection from carcinogens

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Secondary Prevention

• Case-finding surveys (mass/selective screening)
• Screening and follow-up
• Objectives: cure, prevent spread, prevent complications

• Adequate treatment to prevent disability (applied in late pathogenesis)
• Provision of facilities to limit disability

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Tertiary Prevention

• Medical rehabilitation (maximum physical capacity)
• Social rehabilitation (restore social functioning)
• Vocational rehabilitation (gainful employment)
• Psychological rehabilitation

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Concept of the "Iceberg of Disease"

        /\        ← Clinical cases (visible above waterline)
       /  \
      /    \
─────────────────  ← Waterline (clinical threshold)
    /        \
   /   Sub-    \
  /   clinical  \   ← Undiagnosed / sub-clinical cases (below waterline)
 /  Susceptibles \
/________________\  ← Susceptibles

• The tip of the iceberg = symptomatic/diagnosed cases (what clinicians see)
• The submerged portion = sub-clinical infections, undiagnosed cases, carriers, and susceptibles
• This "hidden" mass is the reservoir from which clinical cases emerge
• Screening programs aim to detect sub-clinical disease before it surfaces

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Spectrum of Disease

• Agent factors (virulence, pathogenicity, dose)
• Host factors (immunity, nutrition, genetics)
• Environmental factors

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Significance in Community Medicine

1. Identifies the right point for intervention at each stage
2. Guides screening program design (targeting sub-clinical disease)
3. Explains why prevention is better than cure — intervening early (pre-pathogenesis) is most effective
4. Forms the basis of the Leavell & Clark triad of prevention
5. Helps estimate true disease burden (iceberg concept)
6. Informs the design of health education messages

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Note: K. Park's "Textbook of Preventive and Social Medicine" is not available in this library's collection. This answer is compiled from the established content of that text as it appears in the standard community medicine curriculum, cross-referenced with principles from Harrison's, Goldman-Cecil, and Family Medicine textbooks available in the library.

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Screening of Diseases

(Community Medicine / Preventive Medicine — K. Park Framework)

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Definition

A screening test is not diagnostic — it identifies suspects who require further definitive investigation.

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Purpose / Objectives

• Early detection of disease in its pre-symptomatic phase (secondary prevention)
• Reduce morbidity and mortality from disease
• Identify high-risk individuals for targeted intervention
• Estimate the prevalence of a condition in a community

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Types of Screening

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Wilson & Jungner Criteria (WHO, 1968)

"Principles of Screening"

1. The condition should be an important health problem
2. There should be an accepted treatment for patients with the disease
3. Facilities for diagnosis and treatment should be available
4. There should be a recognisable latent or early symptomatic stage
5. There should be a suitable test or examination for the disease
6. The test should be acceptable to the population
7. The natural history of the disease should be adequately understood
8. There should be an agreed policy on whom to treat
9. The cost of case-finding (including diagnosis and treatment) should be economically balanced in relation to possible expenditure on medical care as a whole
10. Case-finding should be a continuous process and not a once-and-for-all project

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Validity of a Screening Test

                  Disease PRESENT   Disease ABSENT
Test POSITIVE          a (TP)           b (FP)
Test NEGATIVE          c (FN)           d (TN)

• Sensitivity and specificity are relatively independent of prevalence
• PPV and NPV are strongly dependent on prevalence (disease frequency in the population)
• High prevalence → higher PPV for the same sensitivity/specificity
• Screening is most efficient when disease prevalence is high in the target population

Trade-off: Sensitivity vs Specificity

• Lowering the cut-off → ↑ Sensitivity, ↓ Specificity (more FP, fewer FN)
• Raising the cut-off → ↑ Specificity, ↓ Sensitivity (fewer FP, more FN)
• Ideal test: High sensitivity + High specificity

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Reliability (Reproducibility) of a Screening Test

• Observer variation (intra-observer and inter-observer)
• Biological variation in the subject
• Test methodology/equipment variation

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Yield of Screening

• Prevalence of unrecognised disease
• Sensitivity of the test
• The proportion of the population that agrees to be screened
• Number of previously screened individuals in the group

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Biases in Screening

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Harms of Screening

• False-positive results → unnecessary anxiety, further invasive tests
• False-negative results → false reassurance, delayed diagnosis
• Overdiagnosis → unnecessary treatment with attendant side effects
• Radiation exposure (mammography, CT)
• Psychological harm (anxiety during the screening process)

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Evaluation of a Screening Programme

1. Does it reduce cause-specific mortality (not just survival)?
2. What is the number needed to screen (NNS) to prevent one death?
3. What is the gain in average life expectancy for the population?

Example: 731 women aged 65–69 must be screened by DEXA (and treated appropriately) to prevent one hip fracture from osteoporosis. — Harrison's, 22nd Ed.

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Examples of Common Screening Programmes

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Screening vs Diagnosis

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Key Formulas Summary

Sensitivity    = TP / (TP + FN)  × 100
Specificity    = TN / (TN + FP)  × 100
PPV            = TP / (TP + FP)  × 100
NPV            = TN / (TN + FN)  × 100

False Positive Rate = FP / (FP + TN) = 1 − Specificity
False Negative Rate = FN / (FN + TP) = 1 − Sensitivity

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Neonatal Thermal Protection

Short Note — As per OP Ghai's Essential Pediatrics

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Introduction

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Why Neonates Are Prone to Hypothermia

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Normal Neonatal Temperature

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Mechanisms of Heat Loss in Neonates

Evaporation is the most important immediately after birth.

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The "Warm Chain" (10 Steps — WHO)

1. Warm delivery room — temperature ≥25°C (ideally 28°C)
2. Warm resuscitation table — preheated with radiant warmer
3. Immediate drying — dry the baby thoroughly with a warm cloth immediately after birth
4. Skin-to-skin contact — place baby on mother's chest (kangaroo position), cover both with a blanket
5. Breastfeeding — promotes warmth and metabolic stability
6. Postpone bathing — do not bathe for at least 6 hours after birth (24 hours preferred); bathe only when temperature is stable
7. Appropriate clothing and bedding — hat, socks, mittens, warm clothes; cover head (major heat loss area)
8. Mother and baby together (rooming in) — skin-to-skin prevents hypothermia
9. Warm transportation — keep warm during transport; use transport incubator or kangaroo care
10. Training and awareness — train all birth attendants in thermal protection

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Kangaroo Mother Care (KMC)

• Baby placed skin-to-skin on the mother's (or father's) chest between breasts
• Covered with a blanket or mother's clothing
• Especially important for low birth weight (LBW) and preterm babies
• Maintains temperature as effectively as an incubator
• Promotes breastfeeding, bonding, and reduces infection risk
• WHO strongly recommends KMC for all stable LBW infants

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Prevention of Heat Loss at Birth — Immediate Steps

1. Warm the delivery room (≥25°C)
2. Warm the receiving blanket/towel (pre-warmed)
3. Dry immediately and thoroughly
4. Cover head and body; place under radiant warmer

"Dry, Warm, Stimulate" — first three steps of neonatal resuscitation also prevent hypothermia. Wet blankets must be replaced immediately with dry, warm ones.

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Management of Neonatal Hypothermia

Mild/Moderate Hypothermia:

• Skin-to-skin (KMC)
• Warm room, warm clothing
• Ensure breastfeeding or expressed breast milk feeds
• Radiant warmer / warm incubator

Severe Hypothermia:

• Radiant warmer (preferred in sick neonate)
• Warm IV fluids (if needed)
• Treat underlying cause (infection, hypoglycemia)
• Monitor temperature every 15–30 minutes until stable
• Rewarming rate: 0.5°C per hour (rapid rewarming causes apnoea and hypotension)

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Consequences of Hypothermia in Neonates

• ↑ Oxygen consumption and metabolic rate → hypoxia
• Hypoglycaemia (glucose used up for thermogenesis)
• Metabolic acidosis
• Pulmonary vasoconstriction → respiratory distress
• Coagulation defects
• Intraventricular haemorrhage (in preterm)
• Increased mortality — especially in LBW infants

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Neutral Thermal Environment (NTE)

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Key Points for Exam

• Most important immediate measure at birth: drying and wrapping
• Evaporation is the most important route of heat loss at birth
• KMC = most practical and effective thermal protection for LBW/preterm
• Do NOT bathe baby for at least 6 hours after birth
• Normal axillary temp: 36.5–37.5°C
• Neonates cannot shiver — they use non-shivering thermogenesis (brown adipose tissue/BAT)
• Brown fat (BAT) is located in: interscapular region, axillae, around kidneys and adrenals — metabolised to generate heat

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Pathological Jaundice & Management of Neonatal Hyperbilirubinemia

(OP Ghai / Nelson Framework)

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Bilirubin Metabolism in the Neonate

• Higher RBC mass + shorter RBC lifespan (70–90 days vs 120 days in adults) → more bilirubin produced
• Immature hepatic conjugation (low UGT1A1 enzyme activity)
• Increased enterohepatic circulation (high intestinal beta-glucuronidase activity deconjugates bilirubin back to unconjugated form)

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Physiological vs Pathological Jaundice

Key rule: Jaundice appearing in the first 24 hours of life is ALWAYS pathological.

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Causes of Pathological Jaundice

A. Unconjugated Hyperbilirubinemia

• Isoimmune haemolysis — Rh incompatibility (anti-D), ABO incompatibility (most common)
• Hereditary spherocytosis, G6PD deficiency, pyruvate kinase deficiency
• Sepsis (acquired haemolysis)

• Polycythaemia (twin–twin transfusion, delayed cord clamping)
• Cephalhaematoma, bruising, swallowed blood
• Crigler-Najjar syndrome (Type I — complete UGT1A1 absence; Type II — partial)
• Gilbert syndrome
• Hypothyroidism
• Breast milk jaundice (late onset, peaks day 6–14, lasts weeks)
• Lucey-Driscoll syndrome (inhibitor of bilirubin conjugation in maternal serum)

B. Conjugated (Direct) Hyperbilirubinemia

• Biliary atresia (most important — surgical emergency)
• Neonatal hepatitis (TORCH infections — CMV, Rubella, Toxoplasma, Herpes)
• Choledochal cyst
• Alagille syndrome
• Metabolic — galactosaemia, alpha-1 antitrypsin deficiency, tyrosinaemia
• Total parenteral nutrition (TPN) cholestasis
• Sepsis (E. coli, staph)

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Complications

Kernicterus (Bilirubin Encephalopathy)

• Basal ganglia (globus pallidus most affected)
• Subthalamic nuclei, hippocampus, brain stem nuclei

• Prematurity (immature BBB)
• Hypoalbuminaemia (less bilirubin binding)
• Acidosis, hypoxia, sepsis (displace bilirubin from albumin)
• Haemolysis (rapid bilirubin rise)

1. Choreoathetosis / dystonia
2. Sensorineural hearing loss
3. Upward gaze palsy (Parinaud's)
4. Dental enamel dysplasia

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Investigations

Mandatory workup for any neonate with jaundice:

If conjugated hyperbilirubinemia:

• LFTs (ALT, AST, ALP, GGT)
• Urine reducing substances — galactosaemia
• Urine culture — UTI/sepsis
• TORCH serology
• Thyroid function (TSH, T4)
• Ultrasound abdomen — biliary atresia, choledochal cyst
• HIDA scan — biliary atresia (no excretion into gut)
• Liver biopsy — if biliary atresia suspected

Transcutaneous bilirubinometry (TcB):

• Non-invasive, useful for screening
• Needs confirmation with serum bilirubin if high or in high-risk neonates

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Management

1. Phototherapy

• Blue-green light (wavelength 430–490 nm, peak 460 nm) converts unconjugated bilirubin to:
  • Lumirubin (most important product — excreted in bile/urine without conjugation)
  • Configurational isomers (4Z,15E-bilirubin)

• Based on age-specific nomograms (Bhutani curve) — bilirubin level vs postnatal age (hours)
• High-risk neonates (haemolysis, prematurity, sepsis) → lower threshold
• Generally: TSB ≥15 mg/dL at 24–48 hrs in term infant (varies by risk)

• Special blue (narrow-band TL20) fluorescent lamps or LED phototherapy (most effective)
• Irradiance: ≥30 µW/cm²/nm for intensive phototherapy
• Expose maximum body surface area — cover eyes (retinal damage), shield gonads
• Continue feeds — increased fluid intake (↑ insensible losses)
• 4-hourly temperature monitoring
• Monitor bilirubin every 4–6 hours during intensive phototherapy

• Bronze baby syndrome (conjugated jaundice + phototherapy → grey-brown discolouration)
• Loose stools, skin rash
• Hyperthermia, dehydration
• Retinal damage (if eyes unshielded)

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2. Exchange Transfusion (ET)

• TSB ≥20–25 mg/dL in term neonates (age-specific thresholds)
• Rising bilirubin despite intensive phototherapy (>0.5 mg/dL/hr)
• Signs of acute bilirubin encephalopathy at any level
• Haemoglobin <10 g/dL with rapid rise in bilirubin (Rh disease)

• Double volume exchange = 2 × 85 mL/kg = ~160–170 mL/kg
• Removes ~85% of sensitised RBCs and ~50% of bilirubin
• Umbilical venous catheter (UVC) used
• Blood used: O-negative, CMV-negative, irradiated, leucodepleted packed RBCs mixed with FFP (to restore albumin)
• Alternating aliquots of 10 mL (preterm) or 20 mL (term) in/out

• Vascular — air embolism, thrombosis, NEC
• Haematological — thrombocytopenia, coagulopathy
• Metabolic — hypocalcaemia (citrate chelation), hypoglycaemia, acidosis
• Cardiovascular — arrhythmia, cardiac arrest
• Infectious — sepsis
• Graft vs host disease (if not irradiated blood)
• Mortality: ~0.3–0.5%

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3. IV Immunoglobulin (IVIG)

• Indicated in Rh or ABO isoimmune haemolysis when TSB rising despite phototherapy
• Dose: 0.5–1 g/kg over 2 hours
• Mechanism: blocks Fc receptors on macrophages → reduces haemolysis
• Can reduce need for ET

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4. Pharmacological

• Phenobarbitone — induces UGT1A1 (useful in Crigler-Najjar Type II, antenatal preparation)
• Tin-mesoporphyrin — inhibits haem oxygenase, reduces bilirubin production (investigational)
• Albumin infusion — 1 g/kg before ET to bind free bilirubin

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5. Management of Conjugated Hyperbilirubinemia

• Biliary atresia — Kasai portoenterostomy (must be done before 60 days of age for best outcome)
• TORCH infections — specific antiviral therapy where available
• Galactosaemia — galactose-free diet
• Hypothyroidism — thyroxine replacement
• Sepsis — antibiotics
• Fat-soluble vitamin supplementation (A, D, E, K) in all cholestatic infants

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Bhutani Nomogram (Risk Zones)

• High-risk zone (>95th percentile) — act immediately
• High-intermediate zone — close follow-up
• Low-intermediate zone
• Low-risk zone (<40th percentile)

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Summary Table: Management at a Glance

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Hemodynamics of Atrial Septal Defect (ASD)

Short Note — OP Ghai Essential Pediatrics

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Definition

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Types of ASD

ASD should be distinguished from Patent Foramen Ovale (PFO) — PFO is a normal fetal channel that fails to seal postnatally (present in ~20% of adults); it is not a fixed defect.

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Embryological Basis

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Hemodynamics of ASD

Why is the shunt Left → Right?

• Pulmonary vascular resistance (PVR) falls → right-sided pressures decrease
• Left atrial pressure > Right atrial pressure (by ~5 mmHg)
• Right ventricle is more compliant (distensible) than the left → accepts extra volume more readily
• Net result: blood flows from LA → RA through the defect

Consequences of Left-to-Right Shunt:

LA → RA (through ASD)
     ↓
RV receives excess volume → RV volume overload / dilation
     ↓
Pulmonary artery flow increases (Qp:Qs = 2:1 to 8:1)
     ↓
Pulmonary vasculature handles increased flow
     ↓
Pulmonary plethora → progressive pulmonary hypertension (late)

Key Hemodynamic Points:

Why is there no early pulmonary hypertension?

• The shunt is at low pressure (atrial level) — pressure difference between LA and RA is small (~5 mmHg)
• The pulmonary vasculature can accommodate increased volume flow for many years
• Pulmonary hypertension and Eisenmenger syndrome occur late (usually adulthood, 3rd–5th decade)

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Clinical Features

Symptoms:

• Usually asymptomatic in childhood — the hallmark of ASD
• Fatigue, exertional dyspnoea (if large shunt)
• Recurrent respiratory tract infections (increased pulmonary blood flow)
• Rarely: cardiac failure in infancy (large defects)
• Adults: palpitations, AF, stroke (paradoxical embolism via PFO)

Signs:

The murmur of ASD is NOT from the ASD itself — it is a flow murmur across the pulmonary valve due to increased Qp.

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Investigations

ECG:

Chest X-Ray:

• Cardiomegaly (RV and RA enlargement)
• Pulmonary plethora (prominent pulmonary vasculature)
• Dilated pulmonary artery trunk
• Small aortic knuckle

Echocardiography (Investigation of Choice):

• 2D Echo: visualise defect size and location
• Colour Doppler: shows left-to-right shunt across atrial septum
• Bubble contrast echo: confirms shunt
• Estimate Qp:Qs ratio
• Assess RV size and function

Cardiac catheterisation (rarely needed):

• Step-up in oxygen saturation at RA level (oxygenated LA blood mixing)
• Measures Qp:Qs precisely
• Measures PVR before surgery in suspected pulmonary hypertension

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Complications

• Pulmonary arterial hypertension (late, after decades)
• Eisenmenger syndrome — shunt reversal (R→L), cyanosis, polycythaemia (rare in ASD, occurs late in adulthood)
• Atrial arrhythmias — AF, atrial flutter (due to RA dilation)
• Paradoxical embolism → stroke/TIA
• Right heart failure
• Infective endocarditis (uncommon in isolated secundum ASD)

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Management

Indications for Closure:

• Qp:Qs ≥1.5:1 with symptoms or evidence of RV volume overload
• Any symptomatic ASD
• Evidence of paradoxical embolism
• Optimal age: 3–5 years (before school age, before pulmonary hypertension)
• Contraindicated if PVR >8 Wood units (Eisenmenger physiology)

Methods:

Spontaneous closure:

• Secundum ASD <8 mm may close spontaneously in the first 2 years of life
• Large defects and primum/sinus venosus ASDs do not close spontaneously

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Summary: Hemodynamic Sequence

Atrial septal defect
        ↓
LA pressure > RA pressure
        ↓
Left-to-right shunt (LA → RA)
        ↓
↑ RA volume → ↑ RV volume → ↑ Pulmonary flow (Qp ↑)
        ↓
RV dilation + PA dilation + pulmonary plethora
        ↓
Wide FIXED splitting of S2 + Pulmonary flow murmur
        ↓
Late: Pulmonary hypertension → Eisenmenger (reversal)

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Urinary Tract Infection (UTI) in Children

Clinical Features, Investigation, Management & Recurrent UTI

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Definition & Classification

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Epidemiology

• Overall prevalence: ~3–5% in girls, ~1% in boys
• In the neonatal/infant period: more common in boys (due to anatomical phimosis)
• After infancy: girls >> boys (short urethra, perineal colonisation)
• ~30–40% of children with first UTI have vesicoureteral reflux (VUR)
• Uncircumcised boys have 10× higher risk than circumcised

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Aetiology / Causative Organisms

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Pathogenesis & Predisposing Factors

Ascending route (most common):

Predisposing factors:

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Clinical Features

Age-dependent presentation:

Signs:

• Fever (>38°C) — especially in upper UTI
• Suprapubic tenderness (cystitis)
• Costovertebral angle (CVA) tenderness / loin pain (pyelonephritis)
• Abdominal distension (especially neonates)
• In severe cases: signs of urosepsis (shock, tachycardia)

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Investigations

1. Urine Analysis & Culture (cornerstone)

Sensitivity: Pyuria + nitrites combined = ~85–90% for UTI Urine culture is mandatory before starting antibiotics in all children

2. Blood Investigations:

• CBC — leucocytosis (pyelonephritis / sepsis)
• CRP / Procalcitonin — elevated in upper UTI; helps distinguish pyelonephritis from cystitis
• Blood culture — mandatory in neonates, infants <3 months, and ill-looking children (bacteraemia in 4% of febrile UTI)
• Serum creatinine / BUN — assess renal function
• Serum electrolytes

3. Imaging (crucial for structural evaluation):

• Well-responding febrile UTI in 2–24 months: renal USG if not responding in 48 hrs or at completion of treatment
• Abnormal USG or recurrent UTI: MCUG + DMSA

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Management

General Principles:

• Start antibiotic after urine sample is collected (do not delay for culture results in sick children)
• Adequate fluid intake
• Treat constipation and voiding dysfunction if present

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A. Acute Management

Cystitis (Lower UTI — afebrile):

• Oral antibiotics for 3–7 days
• First-line agents:
  • Nitrofurantoin (not <3 months, avoid if renal impairment)
  • Trimethoprim (TMP) or co-trimoxazole (TMP-SMX)
  • Cephalexin / Cefixime
  • Amoxicillin-clavulanate (if organism sensitive)
• Avoid amoxicillin alone (high E. coli resistance)

Pyelonephritis (Upper UTI — febrile):

• Oral cefixime or co-amoxiclav for 10–14 days
• Ceftibuten, ciprofloxacin (older children)

• IV Ampicillin + Gentamicin (neonates)
• IV Ceftriaxone / Cefotaxime (infants and children)
• Switch to oral after 48–72 hrs of clinical improvement

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B. Follow-Up After Treatment

• Urine culture 48–72 hrs after starting antibiotics (test of cure if not improving)
• Repeat culture 1 week after completion to confirm eradication
• Imaging as per protocol

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Vesicoureteral Reflux (VUR) — Key Complication

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Management of Recurrent UTI

Step 1: Identify and correct underlying cause

• Investigate with USG, MCUG, DMSA
• Treat constipation (very common — impairs bladder emptying)
• Bladder-bowel dysfunction (BBD): timed voiding, double voiding, laxatives
• Correct structural anomalies surgically if indicated (PUJ obstruction, PUV)

Step 2: Antibiotic Prophylaxis (Continuous Low-Dose Prophylaxis — CAP)

• Children with high-grade VUR (Grade III–V) — strongest evidence
• Children with structural abnormalities causing urinary stasis
• Children <1 year with any grade VUR (pending resolution)
• Not recommended routinely for children with low-grade VUR or no VUR (NICE/AAP 2011)

RIVUR Study (2014): TMP-SMX prophylaxis reduced recurrent UTI by 50% in children with Grade I–IV VUR, but did not reduce renal scarring and increased antibiotic resistance (from 25% → 68%). — Red Book 2021

• Until VUR resolves (confirmed on follow-up MCUG at 1–2 years)
• Until age 5 years in anatomical anomalies
• Re-evaluate yearly

Step 3: Surgical Management (for VUR)

Step 4: General Measures for Recurrent UTI

• Adequate hydration — dilutes bacteria, promotes bladder washout
• Regular and timed voiding (every 2–3 hours) — avoid infrequent voiding
• Double voiding — void, wait 5 minutes, void again (empties bladder fully)
• Treat constipation aggressively (lactulose, bowel training)
• Perineal hygiene — front-to-back wiping in girls
• Avoid bubble baths, tight clothing
• Circumcision in boys with recurrent UTI and high-grade VUR (reduces recurrence)
• Cranberry juice — some evidence in older girls (not routinely recommended in young children)

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Complications of Untreated/Recurrent UTI

• Renal scarring (reflux nephropathy) → commonest serious complication
• Hypertension (renovascular)
• Chronic kidney disease / end-stage renal disease
• Urosepsis / septicaemia (especially in neonates)
• Renal abscess

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Summary Table: Management at a Glance

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Status Epilepticus (SE) — Criteria & Treatment

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Definition & Diagnostic Criteria

Status epilepticus = seizure lasting >30 minutes, OR two or more sequential seizures without full recovery of consciousness between them.

The shift from 30 minutes to 5 minutes as the operational treatment threshold reflects the fact that most seizures self-terminate within 2–3 minutes; any seizure persisting beyond 5 minutes is unlikely to stop spontaneously and requires treatment. — Katzung's Pharmacology, 16th Ed.; Goldman-Cecil Medicine

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Classification

By Convulsive Activity:

By Treatment Response:

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Aetiology / Causes

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Treatment Algorithm

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PHASE 0 (0–5 min): Active Seizure — Stabilisation

• Airway — position patient, airway adjunct if needed
• Breathing — oxygen (high-flow), pulse oximetry, monitor SpO₂
• Circulation — large-bore IV access × 2, cardiac monitor, BP monitoring
• Glucose — bedside blood glucose immediately; if <60 mg/dL or unknown → 50 mL 50% dextrose IV (preceded by thiamine 100 mg IV if alcoholism/malnutrition suspected)
• Position patient in left lateral position — prevent aspiration
• Labs: CBC, CMP (Na, Ca, Mg, glucose), creatinine, LFTs, AED levels, toxicology screen, ABG, blood cultures if infection suspected
• ECG monitoring

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PHASE 1 (5–10 min): FIRST-LINE — Benzodiazepines

• Lorazepam: less lipophilic → slower redistribution from brain → longer effective duration than diazepam
• IM midazolam = as effective as IV lorazepam in prehospital setting (RAMPART trial)
• Can repeat benzodiazepine once if no response in 5 minutes
• Risk: respiratory depression — have bag-mask ventilation ready

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PHASE 2 (10–30 min): SECOND-LINE — Established SE

Consider intubation at this phase if airway protection is needed or if patient is deteriorating.

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PHASE 3 (>30 min): REFRACTORY SE — ICU Management

• Endotracheal intubation and mechanical ventilation
• Continuous EEG monitoring (to detect NCSE, guide drug titration)
• Neuro-ICU admission

Therapeutic hypothermia is NOT beneficial in SE. — Goldman-Cecil Medicine

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Super-Refractory SE (>24 hrs on anaesthetics):

• Ketogenic diet (via NG tube)
• Pyridoxine (in neonates/infants — B6-dependent SE)
• Immunotherapy — IV steroids, IVIG, plasma exchange (if autoimmune encephalitis)
• Electroconvulsive therapy (ECT) — case reports
• Vagal nerve stimulation
• Surgical resection (if focal structural lesion)
• Transcranial magnetic stimulation (TMS)

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Summary of Drug Doses (Adults)

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In Children (Paediatric Specifics — OP Ghai)

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Monitoring & Investigations During Management

• Continuous EEG — essential once paralysis given; confirms NCSE; guides anaesthetic titration
• CT head — after seizure control (if new-onset SE, focal signs, trauma)
• LP — after seizure control if CNS infection suspected (empiric antibiotics/antivirals should NOT be delayed)
• MRI brain — once stabilised
• Temperature monitoring — treat hyperthermia actively (worsens neuronal injury)

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Prognosis

• Mortality: ~10–20% overall; up to 40% in RSE
• Neurological sequelae in survivors of prolonged SE: cognitive impairment, new-onset epilepsy
• Outcome determined primarily by underlying aetiology, not duration alone

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Hyperkalemia — Investigation & Management

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Definition & Classification

Always exclude pseudohyperkalemia first (haemolysis during phlebotomy — most common in infants/children; prolonged tourniquet, thrombocytosis, leucocytosis). Repeat sample from a free-flowing vein.

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Normal Potassium Physiology

• Total body K⁺ ~3500 mEq; 98% is intracellular (mainly muscle)
• Serum K⁺ is maintained at 3.5–5.0 mEq/L
• Kidney excretes 90–95% of daily K⁺ load via aldosterone-stimulated principal cells of the cortical collecting duct (Na⁺/K⁺ exchange)
• Insulin, catecholamines (β₂), and alkalosis drive K⁺ intracellularly
• Acidosis, cell lysis, and hyperosmolarity shift K⁺ extracellularly

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Causes of Hyperkalemia

1. Excess Intake / Exogenous Load

• Excessive K⁺ supplementation (IV or oral)
• Massive blood transfusion (stored blood K⁺ leaks from RBCs)
• Salt substitutes (KCl-containing)

2. Transcellular Shift (K⁺ out of cells)

• Metabolic acidosis — H⁺ enters cells, K⁺ exits (each 0.1 fall in pH → ~0.6 mEq/L rise in K⁺)
• Insulin deficiency / DKA — insulin normally drives K⁺ into cells
• β-blockers — block β₂-mediated cellular K⁺ uptake
• Hyperosmolarity — draws water and K⁺ out of cells
• Cell destruction / lysis:
  • Rhabdomyolysis
  • Tumour lysis syndrome
  • Haemolytic anaemia
  • Major trauma, burns
  • Massive haematoma

3. Decreased Renal Excretion (most common cause)

• Acute kidney injury (AKI) — especially oliguric
• Chronic kidney disease (CKD) — most common cause overall
• Hypoaldosteronism:
  • Addison's disease (primary adrenal insufficiency)
  • Hyporeninemic hypoaldosteronism (common in diabetes, elderly, CKD)
  • Congenital adrenal hyperplasia (salt-wasting type)
• Distal tubular dysfunction: sickle cell, amyloidosis, obstructive uropathy

4. Drugs (very common)

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Clinical Features

Neuromuscular:

• Muscle weakness (ascending) → flaccid paralysis (in severe cases)
• Paraesthesias
• Fatigue, malaise
• Rarely: respiratory muscle paralysis

Cardiac (most dangerous — from altered membrane potential):

• Palpitations, chest discomfort
• Bradycardia, arrhythmias
• Cardiac arrest (VF or asystole)

GI:

• Nausea, vomiting, abdominal cramping, diarrhoea

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ECG Changes in Hyperkalemia

Any ECG change = cardiac emergency → treat immediately with calcium

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Investigation

Confirm & Grade:

• Repeat serum potassium (to exclude pseudohyperkalemia) — free-flowing venipuncture without tourniquet
• ECG — mandatory; guides urgency

Identify Cause:

Transtubular K⁺ Gradient (TTKG):

• Normal >8–10 (adequate aldosterone-driven excretion)
• <5 in hyperkalemia → renal/aldosterone cause confirmed

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Management

Three Mechanisms of Treatment:

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STEP 1 — Membrane Stabilisation (If ECG changes present)

• Onset: 1–3 minutes; duration: 30–60 minutes — a temporising bridge only
• Caution: Do NOT give calcium in digoxin toxicity (hypercalcaemia + digoxin → "stone heart" / asystole)
• Repeat every 5 minutes if ECG changes persist

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STEP 2 — Intracellular Shift (Lower plasma K⁺ temporarily)

A. Insulin + Glucose (most reliable)

• Regular insulin 10 units IV + 50 mL 50% dextrose (25g glucose) IV
• Onset: 15–30 min; effect lasts 4–6 hours; lowers K⁺ by ~0.6–1.0 mEq/L
• Monitor blood glucose every 30 minutes (hypoglycaemia risk)
• If euglycaemic/hyperglycaemic, give insulin without glucose

B. Sodium Bicarbonate

• 50–100 mEq (1–2 amps) IV over 5–10 minutes (1–2 mEq/kg)
• Most effective in metabolic acidosis (pH <7.3)
• Less effective in normal pH or ESRD (minimal benefit in isolation)
• Onset: minutes; lowers K⁺ by ~0.5–1.0 mEq/L
• Risk: hypernatraemia, volume overload, alkalosis

C. β₂-Agonists (Salbutamol/Albuterol)

• Nebulised salbutamol 10–20 mg (4× normal bronchodilator dose) over 10 min
• OR IV salbutamol 0.5 mg in 100 mL N/S over 15 min
• Onset: 30–60 min; lowers K⁺ by ~0.5–1.5 mEq/L
• Synergistic with insulin
• Caution: tachycardia, may worsen ischaemia; ~20–40% of patients resistant (especially on dialysis)

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STEP 3 — Remove K⁺ from Body (Definitive)

A. Loop Diuretics (if renal function intact)

• Furosemide 40–80 mg IV (or 0.5–1 mg/kg in children)
• Enhances renal K⁺ excretion
• Only effective if urine output maintained

B. Cation Exchange Resins

C. Dialysis (most rapid, definitive K⁺ removal)

• Serum K⁺ >6.5 mEq/L with anuric/oliguric renal failure
• Refractory hyperkalemia not responding to medical treatment
• Severe ECG changes + renal failure
• Concomitant volume overload + hyperkalemia

• Removes 25–50 mEq K⁺/hr
• Dialysate K⁺ = 0 or 1 mEq/L for maximum removal

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Summary: Stepwise Treatment Table

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Management of Underlying Cause

• Stop/reduce offending drugs (ACEi, ARB, K-sparing diuretics, NSAIDs)
• Treat acidosis, AKI, DKA
• Fludrocortisone in hypoaldosteronism/Addison's
• Low-potassium diet (avoid bananas, oranges, potatoes, tomatoes)
• Treat constipation (impairs GI K⁺ excretion)

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Special Situations

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Vitamin D Deficiency (Nutritional Rickets)

Short Note — OP Ghai Essential Pediatrics

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Vitamin D Metabolism

Sunlight (UV 290–320 nm)
        ↓
7-dehydrocholesterol (skin)
        ↓
Previtamin D3 → Cholecalciferol (Vitamin D3)
        ↓ Liver (25-hydroxylase)
25-hydroxyvitamin D3 [25(OH)D3] — storage form; measured in serum
        ↓ Kidney (1α-hydroxylase — stimulated by PTH, low PO₄)
1,25-dihydroxyvitamin D3 [Calcitriol] — ACTIVE FORM
        ↓
Actions: ↑ Ca absorption (gut), ↑ Ca & PO₄ reabsorption (kidney),
         ↑ bone mineralisation, ↑ bone resorption (with PTH)

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Definition

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Aetiology / Risk Factors

Decreased Production / Intake:

• Exclusive breastfeeding without supplementation (breast milk is low in vitamin D — most important risk factor)
• Dark skin (melanin reduces UV-mediated synthesis)
• Limited sunlight exposure — purdah, indoor confinement, high-latitude countries
• Inadequate dietary intake (vegetarian diet, no fortified foods)

Decreased Absorption:

• Coeliac disease, inflammatory bowel disease, cystic fibrosis, cholestatic liver disease
• Short bowel syndrome

Increased Requirement:

• Rapid growth phases — infancy, adolescence
• Prematurity (limited placental transfer; liver immaturity)
• Twin pregnancies

Maternal Deficiency:

• Maternal vitamin D deficiency during pregnancy → neonatal rickets
• Maternal dark skin, purdah, poor diet

Drugs:

• Anticonvulsants (phenobarbitone, phenytoin) — accelerate hepatic 25-hydroxylation → increased catabolism
• Rifampicin, glucocorticoids

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Pathophysiology

↓ Vitamin D
    ↓
↓ Calcium absorption from gut
    ↓
Hypocalcaemia → ↑ PTH (Secondary hyperparathyroidism)
    ↓
PTH effects:
  • ↑ Bone resorption → releases Ca but causes bone loss
  • ↑ Renal Ca reabsorption
  • ↑ Renal PO₄ excretion → HYPOPHOSPHATAEMIA
  • ↑ Renal 1α-hydroxylase activity

Net result:
  Ca may normalise (or be low in early/severe deficiency)
  PO₄ = LOW (phosphaturia from high PTH)
  ALP = HIGH (osteoblast activation)
  ↓ Ca × PO₄ product → failure of bone mineralisation
    ↓
Accumulation of unmineralised osteoid at growth plates → RICKETS

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Clinical Features

Age of Presentation:

• 6 months to 2 years (most common; coincides with peak growth velocity and limited sun exposure in infancy)
• Neonatal rickets — in severely deficient mothers/preterm infants

A. Skeletal Features (most characteristic):

• Craniotabes — softening of skull bones (occipital/parietal); "ping-pong ball" feel on pressing; earliest sign in infants
• Frontal bossing — prominence of frontal and parietal bones (caput quadratum)
• Delayed fontanelle closure
• Delayed dentition; enamel hypoplasia

• Rachitic rosary — bead-like swellings at costochondral junctions (anterior ribs); a classic sign
• Harrison's sulcus (groove) — horizontal groove along lower chest wall at diaphragm insertion (due to softened rib pulling inward)
• Pigeon chest / pectus carinatum

• Kyphosis, scoliosis, lordosis

• Widening of wrists and ankles (most reliable clinical sign after infancy) — expanded metaphyses
• Bow legs (genu varum) — in toddlers who bear weight
• Knock knees (genu valgum) — in older children
• Coxa vara (deformity of femoral neck)
• Greenstick fractures (pathological)
• Delayed walking

B. Non-Skeletal Features:

• Hypotonia ("floppy baby") — generalised muscle weakness
• Hypocalcaemic tetany — carpopedal spasm, laryngospasm, Chvostek's sign, Trousseau's sign
• Hypocalcaemic seizures (early infantile rickets, before skeletal signs develop)
• Pot belly (muscle hypotonia + hepatosplenomegaly)
• Dilated cardiomyopathy (rare but potentially fatal — responsive to Vit D treatment)
• Growth retardation
• Increased susceptibility to infections (impaired immunity)
• Dental: delayed eruption, enamel hypoplasia, caries

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Investigations

Biochemistry:

ALP elevation is the earliest and most sensitive biochemical marker Serum 25(OH)D is the best measure of vitamin D status

Radiology (Wrist X-ray — most informative):

• Widening and blurring of the growth plate (epiphyseal plate)
• Loss of zone of provisional calcification

• Cupping, fraying, and splaying of metaphysis (hallmark)
• Widened metaphysis
• Decreased bone density (osteopenia)
• Cortical spurs, stippling

• Looser's zones (pseudofractures) in severe cases
• Reappearance of zone of provisional calcification (first sign of healing)

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Classification / Types of Rickets

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Treatment

1. Vitamin D Supplementation

• Used when compliance is doubtful
• Oral or IM: 1,00,000–6,00,000 IU (100,000–600,000 IU) as a single dose or divided over 1–5 days
• Preferred in developing countries and resource-limited settings
• 3,00,000 IU (3 lakh IU) single oral dose — widely used in India (OP Ghai)

2. Calcium Supplementation

• Essential — especially in calcium-deficiency rickets
• Elemental calcium: 500–1000 mg/day orally
• Calcium gluconate or carbonate
• Given alongside vitamin D — prevents hypocalcaemia worsening post-treatment ("hungry bones")

3. Diet and Sun Exposure

• Encourage 15–30 minutes of sunlight daily (arms and face)
• Calcium-rich diet: milk, dairy, green leafy vegetables
• Fortified foods

4. Treatment of Complications

• Hypocalcaemic seizures/tetany: IV calcium gluconate 10% — 1–2 mL/kg slowly (0.5 mL/min) under ECG monitoring, then maintenance oral calcium
• Orthopedic correction: most deformities correct spontaneously after 2–3 years of treatment; persistent severe bowing after age 3–4 years may need surgery

5. Special Types

• VDDR Type I: 1-alpha-hydroxyvitamin D (Alfacalcidol) or Calcitriol
• VDDR Type II: Very high doses of calcitriol + calcium infusions
• XLH rickets: Phosphate supplements + calcitriol; burosumab (anti-FGF23) now available
• Hepatic rickets: Water-soluble vitamin D or TPGS formulations

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Radiological Signs of Healing

1. Reappearance of zone of provisional calcification — first sign (within 2–4 weeks)
2. Reduction in metaphyseal cupping and fraying
3. Improvement in bone density
4. Normalisation of ALP (lags behind radiological healing — takes months)

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Prevention

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Key Points for Exam

• Most common cause: Exclusive breastfeeding without VD supplementation in dark-skinned infants with limited sun exposure
• Earliest sign: Craniotabes (infants); widened wrists (older children)
• Most sensitive biochemical marker: ↑ Alkaline phosphatase
• Best serum marker for VD status: 25(OH)D (NOT 1,25(OH)₂D)
• Classic X-ray findings: Cupping, fraying, splaying of metaphysis
• Rachitic rosary = costochondral beading (rickets); not same as "rosary beads" of scurvy (subperiosteal haemorrhage)
• Stoss dose used in India: 3 lakh (300,000) IU single oral dose
• Harrison's sulcus = groove at lower chest margin (diaphragm insertion on soft ribs)
• Chvostek's sign = tapping facial nerve → facial twitch (hypocalcaemia)
• Trousseau's sign = BP cuff inflation above systolic → carpopedal spasm (hypocalcaemia)

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