An 8-year-old boy with psoriasis presented to the dermatology department at New York University with a 2-year history of thick crusted plaques involving >80% body surface area including the scalp, trunk, extremities, hands, and feet. No clinical evidence of arthritis was observed. The patient and his family were offered a variety of treatment options including narrow-band UVB phototherapy, methotrexate, and biologic agents. The patient qualified for enrollment in a multi-institution trial of etanercept in children, and was treated with doses of 0.8 mg ⁄ kg ⁄ week for over 24 months.As the patient's psoriasis, including on his scalp, improved on etanercept, a 9 cm · 8 cm patch of alopecia became increasingly evident at the frontal scalp. The patch was comprised of areas of intense perifollicular inflammation, follicular plugging, and scarring. As a kerion was considered in the differential diagnosis, despite the lack of detectable fungal infection by microscopy or by culture, a 4-week course of oral terbinafine dosed at 125 mg daily (based on body weight 24 kg) was given with no observed clinical improvement. A scalp biopsy revealed scarring fibrosis and some follicles with infundibular hypergranulosis, orthokeratosis, and focal parakeratosis. PAS stain failed to reveal fungi or a thickened basement membrane. A diagnosis of lichen planoplaris was made. Neither a class I topical corticosteroid nor topical tacrolimus improved the patient's condition.Lichen planopilaris is an inflammatory disorder involving the follicular apparatus and is an important cause of scarring alopecia (1,2). While most reported cases involve the scalp, cases involving the face, trunk, and vulva have also been reported. Lichen planopilaris is more common in females than males with typical age of onset between 40 and 60 years and no known racial predilection (1,2). Few cases have been reported in children (3).An association of lichen planopilaris with conditions other than lichen planus has not been firmly established. We are unaware of prior reports of lichen planoplaris occurring in association with psoriasis.Treatment of lichen planopilaris is challenging and has included the use of topical, intralesional, and systemic corticosteroids; cyclosporine; dapsone; topical calcineurin inhibitors such as tacrolimus; and systemic retinoids such as isotretinoin and acitretin (1). Immune suppression has also been achieved with the use of systemic steroid-sparing agents such as azathioprine and mycophenolate mofetil. While treatment with tumor necrosis factor (TNF)-a antagonists has been supported by studies identifying increased TNF-a levels in patients with lichen planus (4), our patient's alopecia was first noted during treatment with etanercept and did not improve during 2 years of therapy. The possible role of TNF-a antagonists in induction of lichen planus has been proposed in at least one other report in which linear lichen planus developed on the leg and foot of a patient undergoing etanercept therapy (5).
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