A 50-year-old woman on hydralazine for hypertension presents with arthralgia, fever, and pleuritic chest pain. Antinuclear antibody test is positive. What is the most likely diagnosis?
- A Systemic lupus erythematosus
- B Drug-induced lupus ✓
- C Rheumatoid arthritis
- D Viral infection
Correct answer: B. Drug-induced lupus
Explanation
Hydralazine is a well-known cause of drug-induced lupus, especially in slow acetylators. The presentation with arthralgia, fever, pleuritis, and positive ANA is classic. Systemic lupus erythematosus would have additional features like renal involvement and anti-dsDNA antibodies. Rheumatitis arthritis causes symmetric small joint synovitis. Viral infection is less likely with positive ANA. Discontinuing hydralazine leads to resolution.
Reference: Katzung Basic & Clinical Pharmacology, 14th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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