Clinical Analysis: 7-Month-Old with Fever (4 days), Jaundice, Petechiae, Deranged BT/PT-INR, Raised Bilirubin, Normal Liver Enzymes, TLC 23,000

Key Clinical Synthesis

• Fever × 4 days (infectious/inflammatory trigger)
• Jaundice (hemolysis or hepatic involvement)
• Petechiae (thrombocytopenia or platelet dysfunction)
• Prolonged Bleeding Time (BT) → platelet dysfunction or thrombocytopenia
• Prolonged PT/INR → coagulation factor consumption
• Raised Bilirubin with NORMAL liver enzymes → hemolytic jaundice (not hepatocellular)
• TLC 23,000 → leukocytosis (infection/sepsis)

Most Likely Diagnosis

🔴 Sepsis-induced DIC (Disseminated Intravascular Coagulation)

"The clinical consequences include a life-threatening combination of bleeding from loss of platelets and clotting factors... and RBC injury and anemia from microvascular hemolysis." — Rosen's Emergency Medicine, p. 111

Differential Diagnosis (in order of priority)

1. Sepsis → DIC (Most likely)

• Gram-negative sepsis (E. coli, Klebsiella, Salmonella, Meningococcus) in a 7-month-old
• Meningococcemia classically: fever + petechiae → can rapidly progress to purpura fulminans
• DIC ISTH score: prolonged PT (2 pts), thrombocytopenia if <100k (1-2 pts), elevated D-dimer (2-3 pts)

2. Hemolytic Uremic Syndrome (HUS)

• Triad: microangiopathic hemolytic anemia + thrombocytopenia + acute kidney injury
• Typically post-diarrheal (STEC O157:H7), but can be atypical
• Elevated bilirubin (hemolysis) + coagulopathy + normal LFTs fits
• Look for: oliguria/anuria, elevated creatinine, schistocytes on smear

3. Malaria (if endemic area)

• P. falciparum in infants: fever, hemolytic jaundice (elevated indirect bilirubin), thrombocytopenia, DIC in severe disease
• Normal transaminases in early stages
• TLC may be normal to elevated

4. Viral hemorrhagic fever / Dengue

• Fever + thrombocytopenia + coagulopathy + jaundice
• TLC 23k less typical (dengue usually causes leukopenia), but possible in secondary infection
• Dengue: PT prolonged, bleeding tendency, elevated bilirubin with modest/no LFT rise early

5. Neonatal/Infantile Immune Thrombocytopenic Purpura (ITP)

• Petechiae + prolonged BT (platelet-mediated)
• But: does NOT cause fever, does NOT cause elevated bilirubin, does NOT prolong PT — less likely

6. Acute Liver Failure with Concurrent Hemolysis

• Wilson disease (though rare at 7 months), galactosemia, tyrosinemia
• But: liver enzymes typically markedly elevated in acute liver failure — makes this less likely given normal enzymes

Critical Investigations to Order Immediately

DIC Diagnostic Scoring (ISTH Overt DIC)

Immediate Management

Stabilize First (ABC)

• IV access, fluid resuscitation if hemodynamically compromised
• Oxygen

Treat the Trigger

• Broad-spectrum IV antibiotics immediately (do not wait for cultures):
  • Ceftriaxone 100 mg/kg/day (covers gram-negatives including Meningococcus)
  • Add ampicillin if Listeria concern (< 3 months; less relevant at 7 months but consider)
  • Cover gram-positives if skin source/MRSA risk

DIC-specific Replacement Therapy (if active bleeding or severe):

• Fresh Frozen Plasma (FFP): 10–15 mL/kg — replaces consumed clotting factors
• Platelet transfusion: if < 20,000 or active bleeding with < 50,000
• Cryoprecipitate: if fibrinogen < 100 mg/dL (rich in fibrinogen, factor VIII, vWF)
• Vitamin K IV: all infants with coagulopathy (rule out hemorrhagic disease of infancy)

Monitor:

• Repeat coagulation profile, platelet count every 6–12 hours
• Urine output (renal function)
• Neurological status

Bottom Line

Sources: Rosen's Emergency Medicine, 9th ed.; Henry's Clinical Diagnosis and Management by Laboratory Methods, 23rd ed.

Revised Clinical Picture with Stable Vitals

Revised Priority Differential

🔴 1. Dengue Fever with Dengue Hemorrhagic Fever (DHF)

The WHO DHF grading:

• Grade I: Fever + non-specific constitutional symptoms + positive tourniquet test
• Grade II: Grade I + spontaneous bleeding (petechiae, gum bleed)
• Grade III/IV: Circulatory failure (shock) — NOT present here

🟡 2. Malaria (P. falciparum or P. vivax)

• Fever paroxysms, hemolytic jaundice (indirect bilirubin ↑, enzymes normal)
• Thrombocytopenia very common in malaria
• BT prolonged due to thrombocytopenia
• PT/INR prolonged in severe malaria
• TLC can be elevated with secondary bacterial infection
• Stable vitals = uncomplicated to moderately severe malaria

🟡 3. Compensated / Early DIC (from occult infection)

• Vitals stable does NOT exclude DIC — chronic/compensated DIC exists
• Sepsis source may be occult (UTI is #1 in this age group — E. coli UTI in a 7-month-old is classic)
• No shock → early/compensated phase

🟢 4. Hemolytic Uremic Syndrome (HUS) — atypical

• Less likely without renal impairment signs, but check creatinine
• Usually post-diarrheal prodrome

Now Focus Your Workup

Most Urgent Tests Given Stable Vitals:

Management with Stable Vitals

Do NOT give antibiotics empirically yet

• Wait for cultures/directed workup unless UTI/occult sepsis confirmed
• Avoid NSAIDs (worsen dengue/malaria thrombocytopenia and bleeding)

Supportive Care:

• Oral rehydration / IV fluids — avoid over-hydration (capillary leak in dengue)
• Paracetamol only for fever (no ibuprofen/aspirin)
• Vitamin K IV/IM (0.5–1 mg for infants) — given deranged PT/INR, rule out Vitamin K deficiency coagulopathy
• No platelet transfusion unless < 10,000 or active significant bleeding in a stable patient

Monitor closely for deterioration:

• Vital signs every 2–4 hours
• Watch for: drop in platelet count, rising haematocrit (dengue plasma leak), fall in BP, altered sensorium
• Day 4–5 of dengue = critical defervescence phase — highest risk of shock

Key Decision Point

Where are you geographically?

• Dengue-endemic area (South/Southeast Asia, sub-Saharan Africa, Latin America) → Dengue DHF is #1
• Malaria-endemic area → Malaria is #1
• Both endemic → Test simultaneously

Why TLC is High (23,000) in This Infant

Causes in THIS Clinical Context

1. Bacterial Sepsis / Occult Bacteremia (most important)

• The classic cause of leukocytosis with left shift (neutrophilia + bands)
• UTI, pneumonia, meningitis, bacteremia — all common at this age
• Leukocytosis + fever + coagulopathy = sepsis until proven otherwise
• Check DLC — neutrophilia + bands = bacterial infection

2. Stress Leukocytosis (Demargination)

• Fever itself causes catecholamine release → demargination of WBCs from vessel walls into circulation
• Can add 10,000–15,000 to baseline count purely from fever stress
• No true infection needed — seen in any severely febrile infant

3. Reactive Leukocytosis from Hemolysis

• Active hemolysis (which this child has, given raised bilirubin with normal enzymes) stimulates bone marrow
• Bone marrow responds to RBC destruction by releasing more cells — including WBCs in the process
• Classically seen in sickle cell crisis, severe malaria, HUS

4. Secondary Bacterial Infection Complicating Primary Viral Illness

• If primary illness is dengue or malaria, a superimposed bacterial infection (aspiration pneumonia, UTI) drives leukocytosis up
• Dengue itself causes leukopenia — so leukocytosis in suspected dengue strongly suggests either:
  • Secondary bacterial co-infection, OR
  • It is not dengue (reconsider diagnosis)

5. Malaria-specific

• P. falciparum: can cause leukocytosis (unlike other species which typically cause leukopenia/normal)
• Monocytosis is characteristic — check DLC for monocytes

6. Early Phase of Viral Illness

• First 24–48 hrs of some viral infections (EBV, CMV, HHV-6) can briefly show leukocytosis before the typical leukopenia/lymphocytosis develops
• At day 4 of fever, this is less likely to still be in that early phase

What the TLC Tells You Diagnostically

Bottom Line

TLC 23k in this child = bacterial sepsis must be actively ruled out, even if vitals are stable now. An occult UTI (commonest serious bacterial infection at 7 months) can present with fever, leukocytosis, jaundice (E. coli UTI causes hemolytic jaundice in infants), coagulopathy — and still maintain stable vitals early on.