According to a recent study, there is a possible link between lichen sclerosus and psoriasis. Data show that female patients with lichen sclerosus of the vulva have a higher prevalence of developing psoriasis, compared to the expected rate in the general population.
Hamilton, New Zealand - A recent case study supports an association between vulval lichen sclerosus and psoriasis. This association may provide a useful insight into the pathogenesis of lichen sclerosus.
"In our case study, we reviewed women presenting with vulval lichen sclerosus and, interestingly, we observed that a higher proportion than expected also had psoriasis," says Amanda Oakley, M.B.Ch.B., F.R.A.C.P., DipHealInf, clinical director, department of dermatology, Waikato Clinical School.
"Thirty-five of the patients in our study (17 percent) gave a history of psoriasis, which affected the vulval area in 10 patients. This is a higher prevalence than the expected 2 to 3 percent in the general population. Most of these patients had a mild psoriasis confined to the scalp, some with moderate and some with severe with extensive plaques.
"Approximately a third of the patients have had psoriasis in the vulva, which may arise before or after a diagnosis of lichen sclerosus," Dr. Oakley tells Dermatology Times.
According to Dr. Oakley, the pathogenesis of lichen sclerosus remains unclear, though up to 60 percent of women with lichen sclerosus have one or more associated autoimmune disease, including thyroid disease, vitiligo, alopecia areata, pernicious anemia, diabetes mellitus and cicatricial pemphigoid. In her study patients, thyroid disease was reported in 39 patients (19 percent), and many patients were atopic (24 percent) and/or had at least one episode of dermatitis in the past (16 percent).
"Treating the symptoms of lichen sclerosus was mostly, but not always, relatively easy to manage with 0.05 percent clobetasol propionate cream or ointment," she says.
Dr. Oakley says clobetasol propionate cream (54 percent) and/or ointment (46 percent) cleared or had a good effect on vulval lichen sclerosus in nearly all patients, including those with vulval psoriasis. Other treatments included mild- to moderate-potency topical corticosteroids, pimecrolimus cream, calcipotriol cream, hydroxychloroquine 200 mg twice daily orally for three months to six months, and prednisone 40 mg orally daily for two months to three months.
Dr. Oakley says that, as with lichen sclerosus, there is a familial association in psoriasis and two distinct disease patterns, and both are T lymphocyte-mediated disorders.
"Like psoriasis, vulval lichen sclerosus can express itself in areas of trauma or scarring," she says.
Although Dr. Oakley's study confirmed a possible link between vulval lichen sclerosus and psoriasis, she says further studies are needed to establish the validity of the results seen in her patients.