Subcutaneous granuloma annulare of the scalp in childhood: a case report and review of the literature.

Granuloma annulare is a benign inflammatory skin lesion of unknown etiology that is usually seen in adults and children and subtypes of it includes localized granuloma annulare, generalized granuloma annulare, subcutaneous granuloma annulare and arcuate dermal erythema. Etiology and pathogenesis of granuloma annulare are obscure, although there is much evidence for an immunologic mechanism. Precipitating factors are insect bites, sunburn, photochemotherapy, drugs, physical trauma, acute phlebitis and sepsis after surgery. Some investigators were suggested a relationship of granuloma annulare to a latent or clinically manifest diabetes or rheumatoid arthritis. In contrast, an association of subcutaneous granuloma annulare with these diseases in childhood has not been reported in the literature. Subcutaneous granuloma annulare of the scalp is rare lesion in childhood and nodules on the scalp are usually non-, or slightly mobile, whereas lesions on the extremities are freely mobile. For definitive diagnosis, a biopsy should be performed but wide surgical intervention or medical treatment is not indicated. In case of recurrence, no additional diagnostic studies are necessary.