Lucio phenomenon – a rare life threatening state of leprosy

The Lucio phenomenon is a highly uncommon and severe form of reactional state associated with leprosy, particularly occurring in patients with untreated diffuse, non-nodular lepromatous leprosy. It manifests as a necrotising form of extensive cutaneous vasculitis, resulting in necrotic and haemorrhagic ulcers on the extremities. Despite its rarity and significant mortality rate, only a limited number of cases have been reported from Asian countries.We present a case of a 56-year-old male diagnosed with lepromatous leprosy and receiving the WHO-recommended multidrug treatment regimen. The patient presented with extensive nodulo-ulcerative lesions and minimal systemic symptoms. Histopathological examination confirmed the diagnosis of Lucio phenomenon rather than ulcerated erythema nodosum leprosum, a condition that mimics Lucio phenomenon. Notably, the patient exhibited a high morphological index (MI) and bacillary index (BI) in slit skin smear, despite receiving the recommended duration of one year of multibacillary treatment.Intravenous immunoglobulin (IVIG) was administered to the patient, resulting in complete re-epithelialization of the ulcers. This case underscores the importance of high clinical suspicion in diagnosing Lucio phenomenon and the timely use of IVIG to halt the progression of extensive vasculitis, thereby minimising complications.