The lepromin (Mitsuda) test is best described as:
- A A diagnostic test that becomes positive early in all untreated leprosy patients
- B A serological test detecting IgM antibodies to phenolic glycolipid-1
- C An intradermal test measuring delayed-type hypersensitivity to M. leprae antigens, useful for classification and prognosis but not diagnosis ✓
- D A skin test that distinguishes leprosy from other granulomatous diseases such as sarcoidosis
Correct answer: C. An intradermal test measuring delayed-type hypersensitivity to M. leprae antigens, useful for classification and prognosis but not diagnosis
Explanation
The lepromin test injects killed M. leprae intradermally and reads delayed hypersensitivity at 48 hours (Fernandez reaction) and 3 to 4 weeks (Mitsuda granuloma). It is positive in tuberculoid disease and negative in lepromatous disease, so it helps classify and predict prognosis, including reactions. It is never used to diagnose leprosy because many healthy contacts in endemic areas are also positive. Serology with anti-PGL-1 IgM is an entirely different test.
Reference: Harrison's Principles of Internal Medicine, 21st ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.