Genital itch is a common complaint. Although many conditions that cause generalized pruritus can affect the genital area, only conditions in which genital itch is a particular feature are included here. Pruritus ani is excluded from this section since its myriad causes would require more space than is available.
History of presenting complaint
• How long has the patient had the problem? Pruritus of short duration is usually related to an infection (for example dermatophyte, candidiasis, scabies or pediculosis pubis) or dermatitis (either irritant or allergic). Chronic pruritus is more commonly related to inflammatory disorders of skin and mucous membranes.
• Is the itch confined to a small part of the genital skin, the whole genital area or does it affect the whole body?
• Are there associated symptoms such as vaginal discharge, rash or ulceration?
• Have they had any significant ill health in the past or any sexually transmitted infections? Ask about skin diseases such as eczema and psoriasis and any history of allergy.
• Take a drug history. Have they tried treating the itch with anything, or could the itching be due to a drug allergy?
• As with any genital complaint, a sexual history is essential. If the history suggests that they could have acquired an STI, offer them an STI screen as well as an assessment of what is causing the itch.
The best clue to the cause of the itch is to first consider the area that is itchy see Table Clinical features of possible causes of genital itch.
Table Clinical features of possible causes of genital itch
Diagnoses to consider
|Generalized itch but particularly bad in genital region||3-10 mm red, often flaky papules/nodules on scrotum, penile shaft or vulva. Person mmnlainincr of Generalized itch. Might be a fine macular rash on trunk. Linear scaly appearance on finger webs or inner aspect of wrists.||Scabies||See site for further information and management advice|
|Any genital site||Fluid-filled blisters or pustules, usually tender, might have tender inguinal lymphadenopathy. Often slight redness and swelling around the lesions. Might have flu-like symptoms||Herpes||See site for further information and management advice|
|Discrete red patches, usually with central clearing and a rim of scale||Dermatophyte infection||Ideally skin scrapings should be sent to the microbiology laboratory for fungal studies before starting treatment. Try an azole antifungal with a mild steroid, e.g. Daktarin HC cream b.d. for 4 weeks.
If symptoms return following blind treatment, send skin scrapings for fungal microscopy and culture
|Thickened white skin with accentuated skin markings, usually seen on vulva but also on scrotum. Less common on penis||Lichen simplex||See site for further information and management advice|
|Discrete red patches. Surface scale unusual. Mild itch only. Might have similar albeit scalier lesions in other sites such as back of the elbows No obvious rash.||Psoriasis||See site for further information and management advice|
|Iron deficiency, hypothyroidism, hepatic or renal impairment. Psychological||Full blood count, ferritin, thyroid status and serum biochemistry. Consider referral to psychologist if all other tests negative.|
|Skin red in folds, particularly perianal region in children. Apparently superinfected genital dermatosis||Beta-haemolytic streptococci, coliforms or Staphylococcus aureus cellulitis||Swab for bacteriology to identify the causal organism, and discover antibiotic sensitivity profile|
|Pubic hair||1-mm diameter dark brown dots adherent to hairs and/or 2-mm diameter pale brown insects gripping tightly to skin. Might complain of having black specks (dried blood) appearing in underwear||Pubic lice, aka crab lice||See site for further information and management advice|
|Vulva||Thick white discharge visible externally or on speculum examination. Sometimes reddening of vulval skin and fissuring, particularly around perineum
Thin discharge, sometimes seems frothy when examined with a speculum. Sometimes reddening of vulval skin extending to thighs
|Vulvovaginal candidosis, aka thrush||See site for further information and management advice|
|Trichomoniasis||See site for further information and management advice|
|White areas of thinned skin probably containing small ecchymoses (bleeding into skin)||Lichen sclerosus. This also occurs in men, but itch is not a prominent feature for men||See site for further information and management advice|
|Flat warty area, poorly responsive to standard wart treatment. Might be pigmented. Patient might have a history of cervical intraepithelial neoplasia (cervical intra-epithelial neoplasia) and probably smokes||Vulval intraepithelial neoplasia||Refer to vulval clinic if available. Otherwise refer to colposcopy.|
|Groin||Characteristically, central clearing and peripheral scaling are seen in annular lesions. Darkened skin is seen in chronic disease||Tinea cruris (a dermatophyte infection)||Good hygiene important — wash with plain water and dry well. Try an azole antifungal with a mild steroid, e.g. Daktarin HC cream b.d. for 4-6 weeks|
|Uncircumcised glans penis||Red blotchy rash||Balanitis (not a diagnosis in its own right. It’s a sign of a large, disparate group of conditions)||Good hygiene important — wash with plain water and dry well. Try an azole antifungal with a mild steroid, e.g. Daktarin HC cream b.d. for 2 weeks|
Hopefully by now you have made a diagnosis and decided on treatment or referral. If in doubt, refer to a genitourinary medicine physician or dermatologist. Some hospitals have special clinics for penile or vulval dermatology staffed by specialists from both departments (and often a gynaecologist or urologist).
General advice for anogenital pruritus includes avoidance of moisture, careful drying if wet, wearing white cotton instead of synthetic undergarments, avoiding prolonged seating on vinyl surfaces to reduce sweating, as well as avoidance of perfumed products or coloured wipes (to decrease the risk of contact sensitization). An emollient such as diprobase or aqueous cream should be used as a soap substitute. Patch testing may be helpful in a few patients, especially if there is any associated erythema. It is preferable to use ointments instead of creams for topical treatment in the anogenital region, as the latter generally contain preservatives and are likely to cause contact allergy.
If you think that the itch is due to an STI, then as well as offering the appropriate treatment it is important to recommend tests for other infections that could have been acquired during the same encounter.