The evaluation of dermatitis herpetiformis begins with a medical history and physical examination.

Physical findings in someone with dermatitis herpetiformis include:

• Red rash with raised blistery skin
• Rash on the back part of the forearms and elbows
• Mouth lesions

The diagnosis of dermatitis herpetiformis is usually made on physical exam.

Tests that may be used to evaluate dermatitis herpetiformis include:

• Skin biopsy:
• With special immune studies that can detect dermatitis herpetiformis
• Thyroid profile
• Thyroid scan