Lues and lupus: syphilis mimicking systemic lupus erythematosus (SLE)

Malar rash and photosensitivity are common findings in systemic lupus erythematosus (SLE). However, a number of inflammatory, dermatologic, infectious or drug-induced conditions may mimic cutaneous findings of SLE. These typically include seborrheic dermatitis, contact dermatitis, rosacea, polymorphous light eruption, syphilis and dermatomyositis sine myositis. Herein we describe a patient with fever, malar rash, alopecia, photosensitivity, arthralgias and lymphadenopathy who was subsequently diagnosed with secondary syphilis. In this case report we review clinical and histopathological findings in the differential diagnosis of malar rash and photosensitivity and discuss the overlapping features of syphilis and SLE.