Under this title are included a number of chronic annular and gyrate eruptions. Individual lesions start as small, pink, infiltrated papules that slowly enlarge and form a ring as the central area flattens and fades. Extension may be irregular to leave arciform segments. The edge may be smooth or scaly, rarely, vesiculation occurs. The lesions are usually located on the buttocks, thighs and upper arms, but any area may be involved. The entire course of the disease lasts for months to years. In the majority of cases the aetiology remains obscure. Trigger factors include fungal infections, drug hypersensitivity, immunologic disorders, blood dyscrasia and neoplastic disease.
Erythema Annulare Centrifugum Darier