The histopathological finding that differentiates lichen planus from lichenoid drug eruptions is:
- A Eosinophils and plasma cells in the infiltrate ✓
- B Saw-tooth rete ridges
- C Band-like lymphocytic infiltrate at the dermoepidermal junction
- D Max-Josef bodies (colloid/civatte bodies)
Correct answer: A. Eosinophils and plasma cells in the infiltrate
Explanation
Both lichen planus (LP) and lichenoid drug eruptions share saw-tooth rete ridges, band-like lymphocytic infiltrate, vacuolar degeneration of basal cells, and colloid bodies (Civatte/Max-Josef bodies). The histological clues favoring a lichenoid drug reaction over idiopathic LP include: the presence of eosinophils, plasma cells, parakeratosis, deeper perivascular infiltrate, and spongiosis. Colloid bodies are seen in both. This distinction matters clinically as management differs.
Reference: Neena Khanna Illustrated Synopsis of Dermatology & STD, 6th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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