Viral Skin Infections

This is a condition caused by the Varicella zoster virus (VZV). It is a common childhood infection. It is characterized by an itchy rash, which appears first on the trunk and spreads out to other parts of the body. Papules and crusts form within a few days. Fever may be present. When the blisters occur they are in crops. The rash lasts 2 to 4 weeks. The condition is usually more severe in the elderly.

Diagnosis
Diagnosis is usually done clinically.

Treatment
Drugs

• Calamine lotion, topically twice daily or
• Chlorpheniramine, adults; 4mg orally twice daily, children up to 10 years; 2mg orally twice daily
• Acyclovir, 800mg orally 5 times daily for 7 days
• Paracetamol, adults; 500mg - 1g orally 3-4 times daily, children; 10-20mg/kg orally 3-4 times daily

This is a condition caused by the resurgence of the Varicella zoster virus. It is characterised by burning pain before the vesicular rash appears. The rash is always unilateral and does not cross the midline (see section 8.8, malignancies).

Treatment
Drugs

• Paracetamol 500mg - 1g orally 3 - 4 times daily.
• Gentian violet may be applied
• Acyclovir 5%, topically 4 hourly for 10 days.
• Acyclovir 800mg orally 5 times daily for 7 days.
• Carbamazepine 200-400mg orally 3 times daily. (for post herpetic neuralgia)

Treat secondary bacterial infection with appropriate antibiotics.

Severe neuralgia should be referred to a neurologist.

This is a condition caused by Herpes simplex virus (HSV) type 1 characterised by a vesicular rash around the mouth or genitalia.

Treatment
Drugs

• Usually, no drug therapy is required
• Wash lesions with saline water
• Paracetamol, adults; 500mg-1 g orally 3-4 times daily, children; 10-20mg/kg orally 3-4 times daily
• Acyclovir cream, 4 hourly.