Professional and Linguistic Assessments Board (PLAB) Practice Exam

Which skin condition is characterized by papules with intense itching and an increase in anti-IGA levels?

1. Contact dermatitis

2. Dermatitis herpetiformis

3. Psoriasis

4. Eczema

The correct answer is: Dermatitis herpetiformis

Dermatitis herpetiformis is a skin condition closely associated with gluten sensitivity and celiac disease. It is characterized by clusters of pruritic papules and vesicles that are intensely itchy, often appearing on the elbows, knees, buttocks, and scalp. The condition stems from an autoimmune response, which leads to the deposition of IgA antibodies in the dermal papillae. This immune response explains the increase in anti-IGA levels, making it a hallmark finding in patients with dermatitis herpetiformis. The presence of intense itching and the papular eruptions helps differentiate it from other skin conditions. While contact dermatitis can also present with itching and rash, it is generally triggered by allergens or irritants rather than a systemic immune response. Psoriasis, on the other hand, is characterized by well-defined plaques with silvery scales and typically does not exhibit significant changes in IgA levels. Eczema, while it can cause severe itching and lesions, does not specifically correlate with increased anti-IGA levels in the same manner as dermatitis herpetiformis. This distinct immune profile and symptomatology align dermatitis herpetiformis clearly with the question’s description.