Dermatitis herpetiformis is likely an autoimmune disease that occurs on the basis of a genetic predisposition, triggered by gluten sensitivity, leading to damage in both the skin and small intestinal mucosa. The skin manifestations are characterized by polymorphic lesions such as erythema, papules, wheals, and blisters. It predominantly affects middle-aged men, with most patients exhibiting allergies to iodine, gluten, and cow's milk. This condition is rare, has a prolonged course, and alternates between exacerbations and remissions. However, the prognosis is favorable, with few fatalities. In children, the disease may naturally resolve after puberty.

bubble_chart Clinical Manifestations

1. The lesions are polymorphic, including erythema, papules, wheals, and blisters of varying sizes. The blisters often cluster densely, with clear fluid and thick walls, showing a negative Nikolsky's sign. After the blisters resolve, significant pigmentation remains. The condition follows a chronic sexually transmitted disease course characterized by recurrent episodes and remissions;
2. The skin lesions are mainly distributed on the scapulae, buttocks, arms, thighs, and extensor surfaces of the elbows and knees, with little to no involvement of the oral mucosa;
3. Cutaneous pruritus is intense, but systemic symptoms are rare;
4. Some patients may develop malabsorption syndrome and steatorrhea.

bubble_chart Diagnosis

1. The skin lesions are polymorphic, characterized by clustered or annular arrangements of serous blisters;
2. The lesions are mainly symmetrically distributed on the shoulders, scapulae, buttocks, arms, sacrum, and extensor surfaces of the elbows and knees;
3. Cutaneous pruritus is severe, but systemic symptoms are rare;
4. It may be accompanied by manifestations of malabsorption syndrome;
5. Histopathology shows subepidermal blisters without acantholysis, with abscesses composed mainly of neutrophils at the tips of the papillae;
6. Direct immunofluorescence (DIF) examination of the perilesional and normal skin reveals granular IgA deposits at the tips of the papillae;
7. Some cases exhibit allergic reactions to iodides;
8. Small intestine biopsy shows focal villous atrophy and chronic inflammatory cell infiltration in the lamina propria.

bubble_chart Treatment Measures

Treatment Principles

1. Avoid foods containing Y gum such as wheat-based foods, and avoid iodine-rich foods like kelp and seaweed;
2. Avoid iodine-containing medications;
3. Systemic drug therapy;
4. Local symptomatic treatment.

1. For mild cases, restricting Y gum-containing diets and symptomatic treatment of skin lesions can control the condition;
2. For more severe cases, dapsone is the first choice, followed by corticosteroids.

bubble_chart Cure Criteria

1. Cured: Rash subsided, symptoms disappeared, and no new lesions appeared;
2. Improved: Partial resolution of rash, symptoms alleviated, with occasional new lesions;
3. Not cured: Continued appearance of new lesions with no improvement in symptoms.