A 13-year-old boy presented with multiple slowly progressive hyperpigmented lesions over face, and papules over dorsum of both hands for last 6 months. There was no history of trauma or pre-existing dermatosis. On cutaneous examination, most of the facial lesions appeared to be annular and atrophic plaques, and were present on forehead, upper lip, nose and preauricular area. Characteristically, they were surrounded by hypopigmented halo (Fig. 1). The papular lesions on dorsa of hands were typically violaceous in color and scaly being of different sizes (Fig. 2). Histopathology demonstrated wedge-shaped hypergranulosis, compact orthokeratosis, apoptotic basal keratinocytes and a dense band-like lymphocytic infiltrates in the papillary dermis with pigmentary incontinence.

Fig. 1 Annular and atrophic violaceus plaques surrounded by hypopigmented halo.

Fig. 2 Violaceous papules on dorsum of right hand.

Lichen planus is an idiopathic papulosquamous inflammatory skin disorder that may have several clinical morphological variants, including plaque, hypertrophic, atrophic, oral erosive, follicular, linear, vesiculobullous, pigmented and actinic variant. Actinic lichen planus, also known as lichen planus subtropicus/tropicus and lichenoid melanodermatitis, is considered as an uncommon photosensitive variant of lichen planus affecting primarily on sun-exposed areas. The classical presentation is gradual development of annular hyperpigmented atrophic plaques mostly over face, surrounded by a hypopigmented halo. Of note, mucosal involvement, pruritus and koebnerization are usually absent in this variant, unlike in classical form.

The differential diagnosis of actinic lichen planus includes lichen planus pigmentosus, polymorphous light eruption, discoid lupus erythematosus, granuloma annulare, sarcoidosis and postinflammatory hyper-pigmentation. Therapeutic options are photoprotection with broad spectrum sunscreens, topical steroids, oral hydroxychloroquine, dapsone, glucocorticoids, and retinoic acid derivatives.