Systemic allergic contact dermatitis from intravesical instillation of the antitumor antibiotic mitomycin C

6 cases of contact allergy to the antitumor antibiotic mitomycin C from intravesical instillation are described. Reports suggest that up to 9% of patients treated with mitomycin C for chemoresection/prevention of superficial bladder cancer will develop cutaneous side-effects. Patients may present either with vesicular dermatitis of the hands and feet and/or dermatitis of the genitals, or with more widespread eruptions. Probably most, if not all, skin reactions are caused by contact allergy. The distribution is suggestive of systemic contact dermatitis from mitomycin C absorbed from the vesical mucosa.