Vulval and scrotal pruritus

Vulval and scrotal pruritus

Cause

Itching of the genital skin is usually caused by skin dis-ease, or by rubbing, sweating, irritation or occlusion. Once started, genital itching seems able to continue on its own.

Presentation

The vulva and scrotum contain nerves that normally transmit pleasurable sensations. However, itching itself is not pleasurable, although scratching is. A torturing itch may be present all day, but more frequently appears or worsens at night. Once scratching has started, it per-petuates itself. The history is of an incessant and embar-rassed scratching. Examination may show normal skin, or the tell-tale signs of excoriations and lichenification.

Differential diagnosis

Itch is part of many inflammatory skin diseases. In the groin its most common causes are tinea, candida, erythrasma, atopic dermatitis, psoriasis, pubic lice, intertrigo and irritant or allergic contact dermatitis. However, patients with ‘essential’ pruritus show no skin changes other than those elicited by scratching. Sometimes the cause is psychogenic, but one should be reluctant to assume that this is the cause. Biopsy rarely helps. Look for clues by hunting for skin dis-ease at other body sites.

Treatment

Low potency topical corticosteroids sometimes help by suppressing secondary inflammation; however, atrophy sometimes quickly occurs, and then the itch is replaced by a burning sensation. A better approach is to eliminate the trigger factors for itchasuch as hot baths, tight clothing, rough fabrics, sweating, cool air, the chronic wetness of vaginal secretions, menstrual pads and soaps. Antipruritic creams, such as doxepin cream, pramoxine cream or menthol in a light emol-lient base, help to abort the itch–scratch–itch cycles. Many patients benefit from systemic antihistamines or tricyclic drugs such as amitriptyline or doxepin.

Complications

Atrophy is common but hard to see. Lichenification creates leathery thickenings, marked with grooves resembling fissures.