Case presentation:
A 75-year-old man, with a skin phototype IV, presented with itchy lesions on the face and the neck, evolving for 1 month. Dermatological examination revealed multiple purplish-brown annular lesions on forearms, neck, scalp and face (Figure 1) with involvement of the lower lip (Figure 2) . Histological examination of biopsy specimen from the forearm and the lower lip showed the same aspect characterized by interface dermatitis with band lymphocytic infiltrate and dermal elastosis (Figure 3) . The clinical presentation, the predilection of the lesions to the photo-exposed zones and the histopathological findings were compatible with the diagnosis of actinic LP.
Actinic LP is a rare variant of LP occurring on photo exposed areas in dark phototype patients. It mainly affects children and young adults.1 Several forms have been described: the annular form as in our case, the dyschromic and the melasma-like form. Unlike LP, mucosal involvement during actinic LP is usually absent and lip involvement is exceptionally reported.1,2
The involvement of the lower lip in our case is explained by an increased exposure to ultraviolet which is considered an important factor in the etiopathogenesis of actinic LP.
The treatment of actinic LP is based on photoprotection and topical corticosteroids. Other treatments have been proposed with variable results: hydroxycloroquine, acitretin, general corticosteroids and cyclosporine.2
Authorship: All authors had access to the data and a role in writing this manuscript.