LICHEN PLANUS SUBTROPICUS: DIRECT IMMUNOFLUORESCENCE FINDINGS AND THERAPEUTIC RESPONSE TO HYDROXYCHLOROQUINE

A 32-year-old black woman presented with the complained of a l-year history of asymptomatic “dark areas” on her face and neck. New lesions developed throughout this time and, once present, slowly increased in size and persisted. She denied systemic symptoms, including arthralgias and myalgias. Her occupation as a real estate agent involved frequent outdoor work. The family history was noncontributory. On physical examination there were multiple hyperpig-mented round-to-oval macules and papules measuring from 0.5 to 2.0 cm in diameter and located over the photoexposed lateral aspects of the face and neck (Figs. 1 and 2). New lesions were papules characterized by a subtle, raised “thread-like” border (Fig. 1, arrow). Older lesions were mac-ular, some with a slightly atrophic, hypopigmented center (Fig. 1, Flesh-colored polygonal papules were present in the V-shaped area on the anterior neck (Fig. 2). The remainder of the cutaneous examination, including the oral mucosa, was unremarkable. Histopathologic examination of a flesh-colored papule viewed on low power revealed a bandlike lymphohistiocytic infiltrate that focally obscured the dermoepidermal junction. Numerous homogenous eosinophilic bodies (Civatte bodies, cytoid bodies, apoptotic cells) and scattered melanophages were identified. In addition, there was epidermal hyperplasia, overlying orthokeratosis, and V-shaped hyper-granulosis. The rete was jagged and possessed a slightly eosinophilic hue (Fig. 3). Hyperpigmented, oval macules had a more patchy lichenoid infiltrate, less epidermal hyperplasia, but possessed a greater number of melanophages in the papillary dermis than new lesions. Periodic acid-Schiff (PAS) stained sections of either type of specimen were negative for basement membrane thickening and also negative for dermal mucin using the colloidal iron reagent. No deposits of immunoglobulin or complement were identified at the dermoepidermal junction by direct immunofluorescence microscopy, but numerous immunoglobulin-coated cytoid bodies were present. Laboratory testing was significant for a negative antinu-clear antibody (ANA) reaction and RPR. A complete blood cell count, results of serum chemistry, and the angiotensin converting enzyme level were within normal limits. Chest roentgenogram revealed no active cardiopulmonary disease. Based on the distinctive histopathology and the impressive, characteristic clinical presentation, the diagnosis of lichen planus subtropicus was made. Therapy with hydroxy-chloroquine 200 mg per day, topical hydrocortisone valerate 0.2% cream b.i.d. to inflammatory lesions, 3% hydroquinone solution b.i.d. to hyperpigmented lesions, and photoprotection were initiated. Partial resolution of the lichenoid lesions has occurred, new lesions have ceased to appear, and the hyperpigmentation has slightly improved.