Unveiling Lepromatous Leprosy in a Non-endemic Region: A Case of Delayed Diagnosis and Effective ROM (Rifampin, Ofloxacin, and Minocycline) Therapy

Leprosy, or Hansen's disease, is a chronic granulomatous infection caused primarily by <i>Mycobacterium leprae</i>. Although its global incidence has declined since the introduction of multidrug therapy (MDT), the disease remains endemic in regions such as India, Brazil, and Indonesia. Additionally, sporadic cases continue to occur in non-endemic areas, including rural areas of the United States, due to migration and travel. We report a 62-year-old male who presented with erythematous, edematous plaques on the arms and trunk, along with progressive hand numbness. He also had a history of frequent travel to Mexico, with the most recent trip nearly a decade prior. After initial misdiagnosis and treatment failure, repeat biopsies revealed numerous Fite-positive acid-fast bacilli. After polymerase chain reaction (PCR) confirmed <i>M. leprae</i>, the diagnosis of lepromatous leprosy was established. The patient was treated with a multidrug regimen consisting of rifampin, ofloxacin, and minocycline (ROM therapy) for 24 months, achieving significant clinical improvement within eight weeks without any significant adverse effects. This case demonstrates leprosy's long incubation period and its ability to mimic other chronic dermatoses, contributing to diagnostic delays. Histopathology combined with PCR was essential for diagnostic confirmation. ROM therapy demonstrated a favorable treatment outcome, presenting a well-tolerated alternative to the World Health Organization's standard MDT regimen with rifampin, dapsone, and clofazimine. Clinicians should maintain a high index of suspicion for leprosy in patients with chronic, non-healing skin lesions, particularly when there is a history of travel to endemic regions, even many years prior. Further research comparing ROM and MDT regimens is warranted.