Reticular erythematous mucinosis on the midline of the back.

We report the case of a 51-year-old man who presented with reticular macular erythema and erythematous plaques on the midline of the back of 10 years' duration that seemed to worsen on exposure to sunlight. Based on the clinical and histopathologic findings, a diagnosis of reticular erythematous mucinosis (REM) was made. The patient was treated with hydroxychloroquine 400 mg daily and the lesions resolved by the end of the second week of therapy.