RESUMO
Lichen planus is considered a T cell-mediated immunological disease. Even mast cells may contribute to the pathogenesis of the disease. Keratinocytes of the basal layer of the skin and/or the hair follicle may represent the "target/victim" of an immune aggression, determining the destruction of the hair follicle and thus scarring alopecia. Therefore, there is a compelling urgency for effective treatment of this potentially disfiguring dermatosis. Our data provide a further therapeutic opportunity: the use of an antihistaminic drug--cetirizine (CTZ)--in an "anti-inflammatory" regimen. We propose the use of CTZ at the dosage of 30 mg/daily. Twenty-one patients affected by lichen planus pilaris (LPP) of the scalp have been treated. Topical application of steroids has been coadministered in all cases during the therapy. Clinical effects, in the sense of stabilization with cessation of the inflammation (erythema, follicular hyperkeratosis, loss of anagen hair), were achieved in all patients but three. One patient developed cardiac arrhythmia after 3 months of successful treatment and dropped out. Our cases indicate that a combined therapy of topical steroid with CTZ can be a safe and effective choice even in severe cases of lichen planus pilaris, so often refractory to the therapy.