Lichen planopilaris.

P, a 20-year-old laborer displayed initial symptoms of the disease in question when he was 10 years old. Initially he had an asymptomatic progressive loss of hair on the scalp. A couple of years later he had mild to moderate pruritis, and the appearance of slate-blue eruptions on the scalp and elsewhere on the body. This resulted in a complete loss of hair on the vault of the scalp, which led him to seek specialist opinion. Skin surface examination revealed the presence of grayish-blue acuminate follicular papules, disposed singly and in groups (plaques). The pilo-sebaceous orifices were conspicuously obliterated and filled by keratin plugs. Perifollicular erythema was a predominant feature on the scalp. The lesions were present over the scalp, around the neck, chest, back, axillae, groin and legs. Shiny atrophied scalp skin depicting scarring alopecia mimicking male-type baldness was a salient feature. In addition, it was studded with conspicuous acuminate papules in its center (Fig. 1a). The known nonhairy (glabrous) skin had classic lichen planus lesions (Fig. 1b). Hemotoxylin-eosin stained microsections prepared from typical lichen planus (LP) lesions over the abdomen and those of lichen planopilaris (LPP) of the scalp were simultaneously studied. The former revealed changes in the epidermis comprising of hyperkeratosis, increase in thickness of stratum granulosum, hydropic degeneration of the basal cell layer and band-like lympho-histiocytic infiltrate pressing against and invading the epidermis, while the latter revealed uniform atrophy of the epidermis and vacuolization of basal cells. The hair follicles were dilated and were filled with keratin plugs. In addition to fibrosis of the dermis, pigment laden microphages and lympho-histiocytic infiltrate was prominent. The follicles and the sebaceous glands were absent. However, arrectores pilorum and sweat glands were preserved (Fig. 2a,b).