The main purpose of the study is to find out

1. the natural course of refractory dermatitis herpetiformis and the development of possible complications
2. the strictness of gluten-free diet treatment in refractory dermatitis herpetiformis

Refractory dermatitis herpetiformis refers to dermatitis herpetiformis unresponsive to gluten-free diet therapy. So far, there is very little knowledge on the course of the disease and the causes and prognosis of refractory celiac disease.

Study patients with refractory dermatitis herpetiformis will be recruited. As a control material dermatitis herpetiformis patients with good response to gluten-free dietary treatment will be recruited.

Inclusion Criteria:

Study patients:

• Dermatitis herpetiformis diagnosis
• Dermatitis herpetiformis rash not responding to a strict gluten-free diet after at least 3 years

Control patients:

• Dermatitis herpetiformis diagnosis
• Dermatitis herpetiformis with good response to a gluten-free diet

Exclusion Criteria:

Study patients:

-Not following strict gluten-free diet

Control patients:

-Not following a strict gluten-free diet

Adult patients with refractory dermatitis herpetiformis