The study will be a prospective evaluation of dapsone gel, 5% in patients with a clinical diagnosis of dermatitis herpetiformis. Active disease must occur on the patients' bilateral elbows or bilateral knees at the time of study enrollment. Active disease will be defined as five or more papules/pustules/vesicles on an extremity. Randomization of one of the patient's extremities (either one elbow or one knee) to the treatment group will occur at time of enrollment. Randomization will be in the sequence of right side assigned to odd numbered patients and left side assigned to even numbered patients. Thus, the first patient to be enrolled, patient number one, would be randomized to treatment on his or her right side. Depending on the site of active disease, he or she would apply topical dapsone gel, 5% to the right elbow or knee twice daily for the duration of the study.