[Actinic lichen planus: 32 cases].

OBJECTIVES

Actinic lichen planus is a variant form of lichen planus located on light-exposed areas, generally in children or young adults with dark skin living in tropical countries. Three forms have been described: annular, pigmented and dyschromic forms. The aim of this work was to determine the epidemiological, anatomic and clinical features of actinic lichen planus in our region.

PATIENTS AND METHODS

A retrospective study included 32 patients with actinic lichen planus on the basis of clinical features and histological findings. The geographical origin, age, sex, phototype and clinical and histological characteristics were recorded for each case.

RESULTS

The incidence of actinic lichen planus was estimated at 1 case per million inhabitants per year. Age in our patients ranged from 7 to 47 years (mean = 17 years), with female predominance (F/M = 2.5). Twenty-six patients were from the Sfax area. Phototypes ranged from III to V, mainly type IV (43.7%). Onset was usually in spring (in 18 cases). Facial involvement was the most frequent (91%) and the annular form predominated (84%); the pigmented form was found in 4 patients and the dyschromic form in 1. Histology showed typical actinic lichen planus in 18 cases and lichen planus in 14 cases.

DISCUSSION

Compared with data reported in the literature, our series showed a low incidence, younger patients and greater female predominance. The annular form appeared to be the most specific. The pigmented form raises problems of differential diagnosis with melasma. Certain histological signs are highly suggestive.