Table I.

Diagnostic procedures in dermatitis herpetiformis (DH) and recommendations regarding when they should be applied

Procedure	Recommendation
Patient history and physical examination
Duration, severity and type of skin symptoms	Always
Presence of gastrointestinal and malabsorptive symptoms and signs	Always
Family history of coeliac disease and DH	Always
Presence of associated autoimmune diseases	Always
Diagnostic procedures
Direct immunofluorescence examination of perilesional skin biopsy	Always
Histopathological analysis of lesional skin biopsy	In obscure cases
Serum tissue transglutaminase or endomysial antibodies	Always
Small bowel biopsy examination	Only if gastrointestinal symptoms not compatible with coeliac disease exist
HLA DQ2 and DQ8 typing	Only in obscure cases