Acute Diarrhea - Adult Management Approach

Step 1 - Assess Severity and Red Flags

Step 2 - Investigations (Selective, Not Routine)

• Bloody/mucoid stool, or fever >38.5°C
• Symptoms >7 days without improvement
• Severe dehydration or systemic signs of sepsis
• Recent antibiotic use (send C. diff PCR/toxin)
• Immunocompromised patient
• Outbreak setting or public health concern

• Multiplex molecular stool panel (PCR) - preferred over traditional cultures; higher sensitivity, faster turnaround
• C. diff toxin/PCR if antibiotic-associated
• Stool for ova and parasites if travel history or symptoms >7 days

Step 3 - Rehydration (First-Line for All)

• Inability to tolerate oral intake
• Severe dehydration
• Signs of sepsis

Step 4 - Symptomatic Agents

• 4 mg loading dose, then 2 mg after each unformed stool, max 16 mg/day
• Safe and effective for watery, nonbloody diarrhea without fever
• Avoid if: bloody stool, fever, suspected C. difficile - risk of toxic megacolon, prolonged fever, hemolytic uremic syndrome (with STEC)

• 524 mg every 30-60 min as needed, up to 8 doses/day
• Reduces stool frequency and nausea; avoid if aspirin-sensitive

• BRAT diet (banana, rice, applesauce, toast) is commonly recommended
• Avoid dairy temporarily (transient lactase deficiency post-viral illness)
• Resume normal diet as tolerated; prolonged fasting is not beneficial
• Goldman-Cecil Medicine, Table 26-5; Symptom to Diagnosis, 4th Ed.

Step 5 - Antibiotics (Rarely Indicated for Acute Diarrhea)

• STEC (E. coli O157:H7) - associated with increased risk of hemolytic uremic syndrome
• Uncomplicated Salmonella (non-typhoidal) in immunocompetent adults
• Goldman-Cecil Medicine, Table 26-5; Rosen's Emergency Medicine; Tintinalli's Emergency Medicine

Step 6 - When to Reassess or Refer

• Diarrhea persisting >7 days without improvement
• New development of bloody stool, fever, or worsening dehydration
• Inability to maintain oral hydration
• Elderly patients or those with significant comorbidities deteriorating

Summary Algorithm

Acute watery diarrhea x2 days, 6 episodes/day, healthy adult
         |
    Red flags? (blood, fever, recent antibiotics, travel, immunocompromised)
    /                \
   YES               NO
    |                 |
Stool testing    Clinical diagnosis (viral gastroenteritis)
Targeted Rx      Supportive care only:
                 - ORS / oral fluids
                 - Loperamide if watery/non-bloody
                 - BRAT diet, avoid dairy
                 - Reassess if >7 days

Treatment for Cracked Soles (Heel Fissures)

Classify Severity First

Grade I - Superficial Fissures

• Apply a thick emollient twice daily - after bathing is optimal when skin is still slightly damp
• Best OTC options: Eucerin, Cetaphil, CeraVe Healing Ointment, petroleum jelly (Vaseline)
• Occlusives (petrolatum-based) are more effective than thin lotions for very dry skin

• Urea works via two mechanisms: humectant (draws water into the stratum corneum) + keratolytic (breaks hydrogen bonds in hardened keratin)
• For Grade I: 10-15% urea cream, applied twice daily
• An RCT (J Tissue Viability 2021, PMID 34090765) confirmed 20% urea cream significantly outperforms placebo for plantar skin hydration - visible softening typically within 3-7 days at 20-25%

• Pumice stone or foot file used on wet skin (after soaking) 1-2x/week
• Removes hyperkeratotic buildup that prevents emollients from penetrating
• Do not file dry skin - always wet first

• Warm water soak for 10-15 min before exfoliation softens the callus
• Avoid prolonged soaking (>20 min) which paradoxically dries skin by disrupting the barrier

Grade II - Moderate Fissures

• Apply high-concentration urea cream at night, cover with cotton socks - the occlusion increases penetration depth substantially
• Known as "sock therapy" or "wet wrap"

• Effective for painful Grade II fissures that do not have signs of infection
• Fills the crack, reduces pain immediately, protects from mechanical stress during healing
• Applied once the crack is clean and dry; reapply as needed

Grade III - Severe/Bleeding Fissures

• Wound care: Clean with saline, apply antimicrobial dressing if infected
• Debridement: Podiatric or dermatology referral for safe removal of deep callus using a blade (do not attempt at home)
• Cyanoacrylate adhesive remains useful for pain relief and closure
• Topical timolol 0.5% gel - a case series (JAAD 2021, PMID 32479981) reported effective healing of deep painful heel fissures with topical timolol, thought to work via beta-receptor mediated keratinocyte proliferation (emerging evidence, off-label)
• If signs of infection (warmth, erythema, purulence): wound culture + topical or oral antibiotics depending on severity

Special Populations

• Heel fissures are high-risk - can be a portal for serious foot infections
• Use 20-25% urea (not higher concentrations that may over-exfoliate fragile skin)
• Avoid blade debridement at home
• Regular podiatry review is essential
• An RCT in diabetic patients showed urea cream reduced deep open fissures from 24% to 6.4% at 4 weeks vs. placebo (p=0.002)

• More prone due to reduced sebaceous gland activity and skin thinning
• Regular moisturizing is preventive, not just therapeutic

Prevention

• Moisturize heels daily year-round
• Wear supportive, closed-heel footwear (open-backed shoes increase heel fat pad splaying and friction)
• Avoid prolonged standing on hard floors without cushioned footwear
• Stay hydrated
• Manage underlying conditions: hypothyroidism, diabetes, psoriasis, eczema - all increase heel fissure risk

When to Refer (Podiatry or Dermatology)

• Grade III fissures with bleeding or signs of infection
• Diabetic foot with any fissure
• No improvement after 4 weeks of consistent topical therapy
• Underlying skin disorder suspected (psoriasis, palmoplantar keratoderma, tinea pedis)

ESR and CRP in Fever - What to Look For

Understanding the Two Tests

• Firestein & Kelley's Textbook of Rheumatology

ESR Reference Ranges and What Elevation Means

• Men: age ÷ 2 mm/h
• Women: (age + 10) ÷ 2 mm/h

Key point: An ESR >100 mm/h almost always has an identifiable serious cause - the underlying diagnosis is usually apparent from history and physical, especially at extreme levels. If no cause is found, repeat in months rather than initiating a blind workup. - Textbook of Family Medicine, 9e

• Best validated for polymyalgia rheumatica and temporal arteritis: 90% of biopsy-proven cases have ESR >30 mm/h (mean ~90 mm/h). A normal ESR does not rule it out - ~4% of cases have normal ESR.
• Monitoring treatment response in PMR/temporal arteritis (falls within days of corticosteroids)

CRP Reference Ranges and What Elevation Means

Critical rule: CRP >10 mg/dL = bacterial infection until proven otherwise. - Firestein & Kelley's Rheumatology

CRP Range Across Conditions

Serum CRP levels (mg/dL) across conditions - Firestein & Kelley's Rheumatology

How to Use Them Together in Fever

Procalcitonin (PCT) - A Better Bacterial Marker

• Normal PCT: <0.1 ng/mL
• Bacterial sepsis: can rise to >100 ng/mL
• PCT is not elevated in viral illness or non-infectious inflammatory states (unlike CRP which rises in both)
• Particularly useful for: antibiotic stewardship (guide duration), sepsis monitoring, differentiating bacterial from viral pneumonia
• Firestein & Kelley's Textbook of Rheumatology

Practical Summary

• Use CRP when you want a real-time inflammatory marker in acute fever - responds within hours, clears fast
• Use ESR when monitoring chronic conditions (PMR, temporal arteritis, TB response)
• CRP >10 mg/dL = strong pointer to bacterial infection
• ESR >100 mm/h = serious underlying disease (infection, vasculitis, myeloma)
• High ESR + low CRP in febrile patient = think SLE or viral illness
• Both normal = makes significant bacterial infection unlikely but does not exclude it
• Neither test replaces clinical judgment - always interpret alongside history, exam, and targeted investigations