Dermatitis herpetiformis (DH) is an extraintestinal manifestation of coeliac disease. The burden of illness in untreated coeliac disease is known to be considerable, but corresponding evidence for DH is lacking. In this study the burden of DH was evaluated prospectively in 52 patients newly diagnosed with DH using a study questionnaire and a validated Psychological General Well-Being (PGWB) questionnaire. The PGWB scores were compared with those of 110 healthy controls. Quality of life was significantly (p < 0.001) lower among patients with DH at the time of diagnosis, but after 1 year on a gluten-free diet their quality of life was at same level as that of the controls. The presence of gastrointestinal symptoms was shown to significantly increase the burden of untreated DH. We conclude that there is a significant burden related to untreated, but not to treated, DH, and the burden is even greater among DH patients with gastrointestinal symptoms.