What is the diagnosis and recommended treatment for a 15-year-old male patient presenting with vesicular skin lesions on the abdominal area, currently using Calmoseptine, and needing a medical certificate for return to school?

Medical Assessment and Management for 15-Year-Old Male with Vesicular Abdominal Lesions

Diagnosis

The most likely diagnosis is Herpes Zoster (Shingles), given the vesicular skin lesions on the abdominal area in a 15-year-old patient. 1, 2

Clinical Reasoning

• Vesicular lesions on the abdomen strongly suggest herpes zoster, which characteristically presents as a unilateral vesicular eruption in a dermatomal distribution 1, 2
• The progression pattern follows: erythematous macules → papules → vesicles → pustules → ulcers 3, 2
• Herpes simplex virus (HSV) is the primary alternative diagnosis but typically lacks the dermatomal distribution characteristic of zoster 1, 2
• In adolescents without immunocompromise, the disease duration is typically 2 weeks with new lesions erupting for 4-6 days 2, 4

Key Diagnostic Features to Confirm

• Look for unilateral dermatomal distribution along thoracic or lumbar dermatomes on the abdomen 1, 4
• Ask about prodromal pain 24-72 hours before rash onset, which strongly suggests zoster 2, 4
• Assess for grouped vesicles on an erythematous base progressing in stages 3, 2

Recommended Diagnostic Testing

Laboratory confirmation should be pursued given the atypical presentation without documented pain: 1, 2

• Tzanck smear from vesicle fluid - shows multinucleated giant cells confirming herpesvirus infection 2
• PCR testing of vesicle fluid - most sensitive/specific method to differentiate VZV from HSV 2
• Open vesicles with sterile needle and collect fluid on swab for testing 3, 2

Treatment Plan

Antiviral Therapy (Within PhilHealth Budget)

Acyclovir 800mg orally 5 times daily for 7 days 3, 4

• Dispense: 35 tablets
• Duration: 7 days
• Cost estimate: ₱150-250 (generic formulation)

Alternative if acyclovir unavailable:

• Famciclovir or valacyclovir may be considered but likely exceed budget 2, 4

Supportive Care

Calamine lotion or zinc oxide cream - continue current Calmoseptine for symptomatic relief

• Dispense: 1 tube (30g)
• Apply to lesions 3-4 times daily as needed
• Cost estimate: ₱30-50

Pain Management (if needed)

Paracetamol 500mg orally every 6 hours as needed for pain

• Dispense: 20 tablets
• Duration: 5 days
• Cost estimate: ₱20-30

Total medication cost: ₱200-330 (within ₱300 budget)

Medical Certificate

Diagnosis: Herpes Zoster (Shingles) - vesicular skin eruption, abdominal area

Recommendation: Rest at home for 7 days with antiviral treatment. Return to school after completion of treatment and when all lesions have crusted over (typically 7-10 days from onset). Patient is advised to avoid contact with pregnant women, immunocompromised individuals, and unvaccinated children until all lesions have crusted. Follow-up if symptoms worsen or new symptoms develop.

Certificate issued for: Medical leave from school due to contagious viral infection requiring isolation and treatment.

Patient/Parent Education

Explain that herpes zoster (shingles) is caused by reactivation of the chickenpox virus 3, 4

• The condition is contagious until all lesions crust over - avoid contact with vulnerable populations 3
• Lesions will progress through stages over 7-10 days before healing 2, 4
• Early antiviral treatment reduces duration and severity 3, 4
• Watch for secondary bacterial infection - increased redness, warmth, purulent drainage 3, 2

Critical Follow-Up Indicators

Return immediately if: 3, 2, 4

• Lesions spread beyond original area or become disseminated
• Severe pain develops or worsens
• Signs of secondary bacterial infection appear
• Eye involvement occurs
• Fever develops or persists beyond 3 days

Important Clinical Pitfalls to Avoid

• Do not assume HSV without confirming dermatomal distribution - both present with vesicles but distribution differs 1, 2
• Absence of pain does not exclude herpes zoster - some patients lack characteristic prodromal pain 4
• In immunocompromised patients, consider chronic ulcerations without vesicular component - but this patient appears immunocompetent 3, 2
• Secondary bacterial/fungal superinfection can complicate healing - monitor for signs 3, 2