Risk of fractures in dermatitis herpetiformis and coeliac disease: a register-based study.

Objectives: Dermatitis herpetiformis (DH) is a cutaneous manifestation of coeliac disease. Bone fracture risk is increased in coeliac disease, but little knowledge exists about bone complications in DH. This study aimed to evaluate the risk of hip and other hospital-treated fractures in DH and coeliac disease in a high prevalence area with good adherence to a gluten-free diet. Materials and methods: Hip, proximal humerus, wrist and ankle fractures in 368 treated DH and 1076 coeliac disease patients between 1970 and 2015 were reviewed from the National Hospital Discharge Register. Hip fracture incidence rates for DH and coeliac disease patients were compared to those for the general population. The overall fracture risk for DH was compared to coeliac disease. Results: The hip fracture incidence rates for DH and coeliac disease patients did not differ from the general population. In females aged 80-89, the hip fracture incidence was higher in DH than in coeliac disease, but the risk for any hospital-treated fracture was lower in DH compared to coeliac disease (adjusted HR 0.620, 95% CI 0.429-0.949). The DH and coeliac disease patients with hospital-treated fractures were diagnosed at an older age, but the degree of small bowel mucosal damage did not significantly differ between patients with and without fractures. Conclusion: The incidence of hip fracture is not increased in treated DH or coeliac disease in an area with high awareness and dietary compliance rates. However, patients with DH seem to have a lower risk for fractures overall compared to coeliac disease.