Neurosyphilis Mimicking Connective Tissue Disease

A male in his 60s developed a pruritic, maculopapular rash on his torso and arms, sparing his palms and soles. He tested positive for ANA and an initial skin biopsy identified "bullous lupus," supporting the diagnosis of a connective tissue disease. Additional symptoms included headaches, facial nerve palsy and hearing loss, which partially responded to oral corticosteroids. He subsequently developed a steroid-dependent left eye scotoma, neuroretinitis and optic nerve papillitis. Mycophenolate mofetil was added but an attempted oral steroid taper led to a worsening rash, progressive retinitis and papillitis. Neurosyphilis was confirmed by serum positive rapid plasma reagin test, reactive treponema pallidum antibodies, positive cerebrospinal fluid venereal disease research laboratory and positive spirochete immunostain of skin biopsy of lesional (rash) tissue. Treatment with intravenous ceftriaxone resolved his rash and visual symptoms. It is important to consider syphilis as a mimicker of connective tissue diseases.