Serial high-resolution ultrasonography demonstrates dynamic inflammatory changes during multidrug therapy in leprosy...

Leprosy is a chronic granulomatous infection caused by Mycobacterium leprae, the leading infectious cause of nerve impairment-related disability. Peripheral neuropathy may occur before, during, or after diagnosis and treatment or as a result of leprosy reactions. High-resolution ultrasonography (HRUSG) provides a more precise evaluation of peripheral nerve abnormality in leprosy patients than clinical examination alone. Longitudinal data assessing dynamic alterations following multidrug treatment (MDT) using HRUSG are limited, especially in endemic settings. We report two leprosy patients who underwent HRUSG evaluation before and after MDT.

Case 1: A 20-year-old male with tuberculoid leprosy presenting with a hypoesthetic hypopigmented plaque on the left arm without palpable nerve enlargement. HRUSG performed before and three months after MDT revealed no nerve abnormalities. Case 2: A 47-year-old male with borderline lepromatous leprosy and severe reversal reaction presented with multiple hypoesthetic erythematous plaques, finger shortening, and stocking anesthesia, without palpable nerve thickening. Pre-treatment HRUSG markedly increased cross-sectional area (CSA) (e.g., ulnar nerve up to 37.0 mm²), hypoechogenicity, and hypervascularity. After two months of MDT combined with corticosteroids, CSA decreased across examined nerves (e.g., ulnar nerve to 27.2 mm²), and hypervascularity resolved in several sites, while hypoechogenicity persisted.

This first longitudinal HRUSG comparison of TT and BL leprosy cases in Indonesia demonstrates that serial ultrasonography can detect subclinical nerve involvement and document early structural improvement during therapy. HRUSG may serve as a non-invasive adjunct for monitoring inflammatory activity and therapeutic response in leprosy neuropathy.