Not All Rashes Are Allergic: Keratoderma Blennorrhagicum-Like Rash Masquerading as Contact Dermatitis

A 56-year-old Caucasian man was referred to the allergy clinic for evaluation of palmoplantar dermatitis. The patient’s rash developed one year prior to presentation. He described erythema, pruritus, and hyperkeratosis of the involved skin with the eventual development of deep fissuring. He had a history of onychomycosis of his toenails but no history of fungal skin rash. He was exposed to solvents, mineral spirits, and gasoline through his occupation in home renovation and wearing neither nitrile nor cotton gloves alleviated his symptoms. Prior evaluations were carried out by primary care and dermatology. He had been treated with topical emollients, topical steroids (including potent agents such as clobetasol) for suspected atopic dermatitis, and topical antifungal agents as well (although KOH prep was negative). All prior treatments failed to resolve his severe palmoplantar rash