Annular lichen planus

Annular lichen planus (LP) is a rare form of lichen planus, which is a condition that affects the skin and/or mouth. In annular LP, specifically, affected people develop ring-shaped, slightly raised, purple lesions with no central atrophy (tissue breakdown). Purely annular LP is very rare; however, annular lesions occur in approximately 10% of all cases of lichen planus. The exact underlying cause of annular LP is unknown. Treatment is not always necessary as some cases of annular LP resolve on their own. Mild cases can often be managed with topical steroids, while more intensive therapies may be required for severe cases.