**Core Concept**
Dermatitis herpetiformis is a chronic skin condition characterized by intensely itchy, blistering rash. It is associated with gluten sensitivity and celiac disease, and treatment involves addressing the underlying gluten intolerance.

**Why the Correct Answer is Right**
The drug of choice for dermatitis herpetiformis is dapsone, a sulfonamide antibiotic derivative. Dapsone works by inhibiting the production of leukotrienes, which are pro-inflammatory mediators involved in the pathogenesis of the disease. Dapsone also has anti-inflammatory properties, which help to reduce the severity of the rash. In addition, dapsone has been shown to improve the intestinal absorption of nutrients in patients with celiac disease, further supporting its use in the treatment of dermatitis herpetiformis.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect as it does not specify a treatment for dermatitis herpetiformis. While antihistamines may provide some relief from itching, they do not address the underlying cause of the disease.
**Option B:** This option is incorrect as corticosteroids may provide short-term relief from symptoms but do not address the underlying gluten intolerance. Long-term use of corticosteroids can also lead to significant side effects.
**Option C:** This option is incorrect as it does not specify a treatment for dermatitis herpetiformis. While antibiotics may be used to treat secondary bacterial infections, they do not address the underlying cause of the disease.

**Clinical Pearl / High-Yield Fact**
Dapsone is often used in combination with a gluten-free diet to manage dermatitis herpetiformis. Patients with dermatitis herpetiformis should also be screened for celiac disease and other autoimmune disorders.

**Correct Answer:** D. Dapsone