Inflammation and Immune Pathology USMLE Step 1 Practice Question
A 38-year-old man with no prior skin conditions presents with erythematous, scaly patches on his elbows and knees. Vital signs: BP 128/82, HR 88, RR 16, Temp 37.2°C. Removing scales reveals pinpoint bleeding. Serum uric acid is elevated at 7.8 mg/dL. Histology shows acanthosis, parakeratosis, and elongated rete ridges with dilated capillaries in dermal papillae. Joint pain is notably absent. Which pathologic mechanism best explains the epidermal hyperplasia in this condition?
Answer choices
- AType I hypersensitivity with IgE deposition in the basal layer
- BBacterial lipopolysaccharide-induced chronic granulomatous inflammation
- CAntibody-mediated destruction of desmosomes
- DMast cell infiltration with tryptase-mediated collagen degradation
- EIncreased keratinocyte proliferation driven by Th17 cytokines IL-17 and IL-22Correct answer
- FAutoimmune destruction of melanocytes with compensatory epidermal proliferation
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