A 32-year-old man with chronic diarrhea and iron deficiency anemia has intensely pruritic grouped vesicles over the extensor surfaces of elbows, knees, and buttocks. Direct immunofluorescence of perilesional skin shows granular deposits of IgA concentrated at the tips of dermal papillae. Which dietary factor perpetuates this eruption?
- A Lactose in dairy products
- B Purine-rich organ meats
- C Gluten-derived gliadin peptides ✓
- D Iodide in table salt
Correct answer: C. Gluten-derived gliadin peptides
Explanation
This is dermatitis herpetiformis, the cutaneous manifestation of celiac disease. Granular IgA at dermal papillary tips against epidermal transglutaminase causes neutrophilic microabscesses and subepidermal blisters. Both the rash and the enteropathy respond to a strict gluten-free diet, since gliadin peptides drive the immune response. Purines relate to gout, not this condition.
Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.