A 30-year-old man develops recurrent crops of brown scaly papules on the trunk and extremities that resolve slowly over weeks. A biopsy from a fresh lesion shows parakeratosis, mild spongiosis, and a lymphocytic infiltrate with extravasated red blood cells. The most likely diagnosis is:
- A Pityriasis lichenoides et varioliformis acuta
- B Pityriasis lichenoides chronica ✓
- C Lymphomatoid papulosis
- D Psoriasis
Correct answer: B. Pityriasis lichenoides chronica
Explanation
Pityriasis lichenoides chronica presents with recurrent brown scaly papules and shows mild interface dermatitis with extravasated RBCs. PLEVA shows more necrosis and ulceration. Lymphomatoid papulosis shows atypical CD30+ lymphocytes. Psoriasis shows regular acanthosis and Munro microabscesses.
Reference: Bolognia's Dermatology, 4th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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