Kitty Litter Dermatitis from-Bromo-2-Nitropropane-1,3-Diol

70-year-old white man presented with a 6-week history of an acute pruritic eruption in the axillary vaults, inguinal folds, and central lumbar area. Due to the severity of the pruritus, the patient was evaluated in the emergency department. He was treated with intramuscular triamcinolone, oral fluconazole, clobetasol cream, and miconazole powder, which provided only minimal relief. The patient had presented with brightly erythematous patches in the axillary vaults and inguinal folds with numerous erythematous, scaly, coalescing papules and plaques agminated on the lumbar region (Figure). Due to persistence, despite topical corticosteroids, an allergic contact dermatitis was suspected so patch-testing using the T.R.U.E. Test (SMARTPractice Denmark ApS, Hillerod, Denmark) epicutaneous system was conducted. Results were positive for 5-chloro-2-methyl-4-isothazolinone (panel 2.1, #17), budesonide (panel 3.1, #30), and 2-bromo-2-nitropropane-1,3-diol, also known as bronopol (panel 3.1, #36). The patient's topical medications were adjusted based on these results, and he was advised to avoid any products containing these contactants.