What is the treatment for dermatitis herpetiformis?

Treatment of Dermatitis Herpetiformis

A strict, lifelong gluten-free diet (GFD) is the cornerstone of treatment for dermatitis herpetiformis, with dapsone used as initial adjunctive therapy to rapidly control skin symptoms until the GFD becomes effective. 1

Understanding the Disease

Dermatitis herpetiformis is the cutaneous manifestation of gluten-sensitive enteropathy (celiac disease), characterized by intensely itchy urticated papules and small blisters typically on the elbows, knees, buttocks, and scalp. 1 This is fundamentally different from other forms of eczema or dermatitis—it requires addressing the underlying gluten sensitivity, not just treating the skin. 2

Primary Treatment: Gluten-Free Diet

The gluten-free diet addresses both the skin manifestations and the underlying enteropathy and must be maintained lifelong. 1

• A strict GFD reduces the daily requirement of dapsone significantly, with 93% of patients able to reduce their dapsone dose compared to only 16% on a normal diet. 3
• After one year on a GFD, patients need approximately 40% of their original dapsone dose, and after 3 years only about 20%. 3
• More than 70% of patients can discontinue dapsone entirely within 24 months of strict GFD adherence. 1
• Complete remissions occur only in patients on a GFD—28% of patients achieve complete remission and remain asymptomatic without any medication when they observe a strict diet. 3
• The response to GFD occurs regardless of the severity of jejunal mucosal changes or HLA-B8 status. 3

Consultation with an experienced dietitian who understands both celiac disease and dermatitis herpetiformis is essential for proper dietary management. 1 Patient education, motivation, and support are critical for achieving dietary adherence. 1

Adjunctive Pharmacologic Treatment: Dapsone

Dapsone provides rapid relief of skin symptoms while waiting for the GFD to take effect, which may take months. 1, 4

• Dapsone is FDA-approved as a primary treatment for dermatitis herpetiformis. 4
• The mechanism of action in dermatitis herpetiformis has not been fully established, but it provides effective symptom control. 4
• Dapsone is rapidly and almost completely absorbed when given orally, with peak concentration reached in 4-8 hours. 4
• Daily administration for at least 8 days is necessary to achieve a plateau blood level. 4
• The drug should be gradually reduced as the GFD takes effect rather than stopped abruptly. 1

Long-Term Benefits and Outcomes

A strict GFD reduces the risk of developing non-Hodgkin's lymphoma, which is increased in untreated dermatitis herpetiformis with severe gut involvement. 1

• GFD improves nutritional parameters and bone mineral density, with greatest improvements occurring in the first years of treatment. 1
• Loss of IgA from the skin (indicating immunologic resolution) occurs in approximately 24% of patients taking strict gluten-free diets for an average of 13 years. 5
• In severe forms of dermatitis herpetiformis, 87% of patients showed complete remission of skin manifestations after 18 months of GFD alone, with 13% showing improvement. 6

Monitoring and Follow-Up

Regular follow-up is necessary to monitor dietary adherence and clinical response, with annual follow-ups once disease is stable. 1

• Monitoring should include assessment of nutritional status, screening for associated autoimmune conditions, liver function tests, and dietary adherence evaluation through structured dietary interview and possibly serological testing. 1
• Negative serological tests do not necessarily indicate complete mucosal healing in adults. 1
• Even patients with normal villous architecture but increased intraepithelial lymphocytes should adhere to a GFD. 1

Critical Pitfalls to Avoid

Do not treat dermatitis herpetiformis like atopic dermatitis or other forms of eczema—topical corticosteroids are not the primary treatment. The disease requires addressing the underlying gluten sensitivity. 1, 2

• Dietary adherence can be challenging but is essential for long-term disease control—emphasize that this is not optional or temporary. 1
• Do not discontinue dapsone too rapidly before the GFD has had time to become effective (typically several months). 1
• Do not confuse dermatitis herpetiformis with eczema herpeticum (HSV infection of eczematous skin)—these are completely different conditions requiring different treatments. 7
• Avoid assuming that partial gluten restriction is sufficient—the diet must be strict to achieve optimal outcomes. 5