Chemical Tattoo Treatment Leading to Systemic Cobalt Hypersensitivity

An otherwise healthy 36-year-old Caucasian woman, without prior history of atopic dermatitis or eczema, presented to an outside dermatologist with a generalized, severely pruritic eruption involving the entire body except the face. One month previously, she had used a 50% trichloroacetic acid tattoo removal solution on a blue-colored tattoo on the medial aspect of the left ankle. The patient's eruption persisted for 7 months, and after several attempts to slowly taper her prednisone dose, she presented to our institution. On physical examination, there was a 3-cm erythematous, lichenified plaque surrounding the tattoo (Figure). On the trunk and upper regions of the arms, there were scattered, 1- to 2-cm, nummular patches and plaques. Biopsy of a truncal lesion revealed spongiotic pustules with a mixed dermal infiltrate and scattered eosinophils, consistent with subacute spongiotic dermatitis.