Genital herpes zoster
Aetiology
- After chickenpox, the herpes zoster virus lies dormant in a sensory nerve ganglion.
- If reactivated later, shingles presents in the affected dermatome.
- More common in the elderly, immunosupressed and those with haematological malignancies.
Presentation
- Unilateral pain (often severe) and itching in perineal area. May have fever.
- A few days later, unilateral vesicular rash develops in the region of the affected nerve.
- Dries, crusts and heals over the following few weeks.
- Pain may persist for months, especially in the elderly (post herpetic neuralgia).
- Risk of secondary infection and dysuria.
Management
- Usually clinical diagnosis but viral swab can be taken for confirmation.
- Antiviral therapy recommended for the over-sixties or if immunosupressed.
- Treatment is aciclovir 800mg five times daily for seven days. More effective if started within 72 hours of rash onset.
- Topical calamine lotion or wet dressings with 5% aluminium acetate.
- Topical lidocaine for painful urination.
- Analgesics for pain. If necessary add amitriptyline, gabapentin or topical capsaicin.
Herpes simplex presents with small painful blisters
Genital herpes simplex
Aetiology
- Caused by the herpes simplex virus, usually type-2.
- Usually sexually transmitted.
- Following initial infection, the virus lies dormant but may reactivate.
Presentation
- Itching, tingling and burning in the perineal area.
- Groups of small painful blisters develop on the labia, vagina or cervix.
- Risk of secondary infection, dysuria and retention of urine.
- Risks in pregnancy include microcephaly, microphthalmia, intracranial calcifications or chorioretinitis.
Management
- Diagnosis may be confirmed by viral swab of blister fluid.
- Topical treatment as for herpes zoster.
- Early treatment with an antiviral (aciclovir 200mg five times daily for five days) may settle the condition quicker.
- Prophylactic antiviral therapy for frequent recurrences for up to six to 12 months.
