Alitretinoin for Hypertrophic Lichen Planus.

Dear Editor:

A 69-year-old male presented with a 1-year history of pruritic skin lesions affecting the extremities. He had no underlying disease or drug history. He had been diagnosed with viral warts and recommended cryosurgery in another Dermatology clinic. Physical examination revealed pruritic, purpuric hyperkeratotic plaques covered with whitish fine scales on both hands, ankles, and feet (Fig. 1A~C). Analysis of a specimen obtained from his right hand via punch biopsy revealed hyperkeratosis, acanthosis, thickening of the granular layer, and lichenoid lymphocytic infiltration with scattered eosinophils (Fig. 2). We received the patient’s consent form about publishing all photographic materials. Based on these clinical and histopathological findings, a diagnosis of hypertrophic lichen planus (HLP) was made. The patient was treated with oral alitretinoin (9-cis-retinoic acid) 30 mg/day for the first 2 months, and 10 mg/day for the next 2 months; subsequently, the lesions exhibited dramatic improvement after 4 months of treatment, and no recurrence occurred during 18-months follow-up (Fig. 1D~F). Alitretinoin was generally well tolerated, with no detectable adverse effects. Lichen planus is a chronic inflammatory skin disease, which is characterized by lichenoid skin inflammation with severe pruritus1. Compared to classic lichen planus, HLP tends to involve more pruritis and be more refractory to treatment; it also involves an increased risk of squamous cell carcinoma23. Alitretinoin is a vitamin A derivative, known to act as a panretinoic acid receptor agonist; importantly, it exhibits anti-inflammatory and immunomodulatory activities4. Because of its dual receptor activity, alitretinoin is more effective than other retinoids in treatment of patients with retinoidresponsive dermatoses5. Moreover, alitretinoin has a relatively favorable safety profile among vitamin A derivatives4. Therefore, we propose alitretinoin as a treatment option for patients with refractory and/or multiple severe HLP lesions.

Fig. 1

(A~C) Multiple hyperkeratotic plaques covered with whitish scales on both hands, ankles, and feet. (D~F) Improvement after 4 months of alitretinoin treatment.

Fig. 2

(A, B) Hyperkeratotic irregularly acanthotic epidermis, thickening of the granular layer, and hypergranulosis with lichenoid interface dermatitis representing hypertrophic lichen planus (A: H&E, ×40; B: H&E, ×100). (C) Lichenoid infiltration of lymphohistiocytes and eosinophils (H&E, ×400).