[Leprosy with an unusual course]

In developed countries, Hansen disease, or leprosy, is a rare and little-known disease. Over the last few years, its prevalence in New Caledonia has remained stable (0.35 per 10,000 inhabitants). We report the case of an 11-year-old child who presented lepromatous leprosy complicated by a type 2 reaction. Despite appropriate treatment, the course was unusual with fever lasting a few weeks associated with asthenia, weight loss, and biological perturbations such as inflammatory syndrome, anemia, and hyperferritinemia. After a brief review of Hansen disease and its complications, we discuss the different hypotheses that can explain the clinical and biological progression of our patient (hemolytic anemia secondary to dapsone, type 2 reaction, and aspects of hemophagocytic syndrome) and describe therapeutic management, which led to a good outcome.