We report the case of a patient who developed allergic contact hand dermatitis while receiving infliximab infusions for psoriasis and psoriatic arthritis. Patch testing showed multiple positive allergens. To our knowledge, this is the first case report of successful patch testing in a patient receiving tumor necrosis factor–alpha (TNF-α) blockade therapy. TNF-α blockers do not necessarily suppress allergic contact hypersensitivity and are not an absolute contraindication to patch testing.