THERAPEUTIC HOTLINE Effectiveness of the association of cetirizine and topical steroids in lichen planus pilaris – an open-label clinical trial Roberto d’Ovidio*, Alfredo Rossi†&Tiziana Maria Di Prima‡ *AIDA-Tricologia and †Clinica Dermatologica, Università “La Sapienza,” Roma, I Clinica Odontoiatrica and ‡Università di Catania, Italy ABSTRACT: 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 treat- ment of this potentially disfigurating 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 coadministrated 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. KEYWORDS: cetirizine, lichen planus pilaris, topical steroid Introduction Lichen planus pilaris (LPP) is characterized by permanent loss of hair and visible follicular ostia with other minimal or evident inflammatory signs (erythema and follicular hyperkeratosis, telang- iectasia, melanin spreading), whereas from the histopathological point of view, there is hyper- granulosis, hyperkeratosis, acanthosis, degenera- tion of basal keratinocytes, and destruction of the basal membrane. In the superficial dermis, there is a band-like lymphomononuclear infil- trate, responsible for the destruction of the base- ment membrane, the basal layer, and outer epithelial sheets of the follicles. This infiltrate involves the follicle between the infundibulum and isthmus but spares the lower portion. There is a replacement of follicular structures with scar- like fibrous tissue. Anagen hair with gelatinous sheath can be extracted from the active border of the areas (FIG. 1). Scalp itching can be often asso- ciated with the disease. Lichen planus (LP) is now Address correspondence and reprint requests to: Roberto d’Ovidio, MD, AIDA-Tricologia, v.Campione, 2; 70124 Bari, Italy, or email: robdovi@tin.it. 547 Dermatologic Therapy, Vol. 23, 2010, 547–552 Printed in the United States · All rights reserved © 2010 Wiley Periodicals, Inc. DERMATOLOGIC THERAPY ISSN 1396-0296