This boy developed progressive hyperpigmented atrophic plaques with hypopigmeted halos on sun exposed areas of the face. Note the sparing under his nose. The plaques of actinic lichen planus or lichen planus actinicus are confined to the light exposed areas and are usually annular. They probably represent an isomorphic phenomenon and are most commonly found on the lateral aspects of the forehead and tops of the hands. This variant may account for 20-30 percent of cases of lichen planus in the Near East and has benn shown to be triggered by ultraviolet B light. The eruption tends to improve in the winter and flare in summer. Histopathologic features are typical of lichen planus.
Grayish brown annular plaques with hypopigmented halos