QWhat is your initial workup for patients presenting with vulvar/genital itching?
When a patient presents with genital itching, I first obtain a few crucial details. I ask about a history of dermatologic disease, particularly psoriasis or eczema, as those can present as pruritic patches or plaques on the genitals. Also, the age of onset is key, as lichen sclerosus (LS) typically occurs after menopause in women, but lichen simplex chronicus (LSC, synonymous with eczema in the genital area) arises at any age. If they have an itch-scratch cycle, meaning it feels good to scratch but makes them itch more afterwards, that is consistent with LSC. Finally, I inquire about products, both over the counter and prescription, they have used, as many ingredients cause either allergic or irritant contact dermatitis1, 2.
Next, the physical exam is critical. LS has the characteristic appearance of atrophic white plaques, frequently with purpura if the patient has been scratching. LS is occasionally hypertrophic, but there is always a texture change. LSC looks subtle if not longstanding, but you should see some lichenification and accentuation of skin lines. Color change is a feature and depends on the patient’s skin type. In lighter skin, the plaques are pink or hyperpigmented, while in darkly pigmented skin, they sometimes appear hypopigmented. Genital psoriasis appears non-specific compared to psoriasis on non-genital skin and presents as pink patches without much scale. If you suspect psoriasis, examine the non-genital skin. In my experience, scalp psoriasis tends to co-exist with genital psoriasis. Finally, either irritant or allergic contact dermatitis causes geometric pink to red patches or plaques, at times with erosions because vesicle usually erode due to friction and moisture in the genital area.
Most importantly, if you are unable to make a diagnosis based on the history and exam, consider performing a biopsy, which should be read by a dermatopathologist.
1. L. Morrison, C. LeClair. Red Rashes of the Vulva. Obstet Gynecol Clin N Am: 44 (2017) 353-370.
2. Harper, J and Zirwas, M. ACD of the Vagina and Perineum: Causes, Incidence of, and Differentiating Factors. Clin Obstets and Gynecol: 58 (2015) 153-157.