A rare occurrence of lepra Type II reaction in pure neuritic leprosy: a case report

BACKGROUND: Pure neuritic leprosy (PNL) is an uncommon clinical form of leprosy characterized by nerve involvement without skin lesions, making diagnosis challenging. Type II lepra reaction (erythema nodosum leprosum, ENL) is rarely associated with PNL. CASE PRESENTATION: We report a 39-year-old male from Harar, Ethiopia, who presented with a 10-month history of progressive numbness, tingling, and weakness in the left hand. Clinical examination revealed thickened and tender ulnar nerve, sensory loss, hypothenar atrophy, and clawing of the ring and little fingers. Nerve conduction studies confirmed severe ulnar neuropathy, and ear-lobe biopsy was Negative for Bacilli establishing the diagnosis of PNL with Grade II disability based on clinical basis according to WHO classification after taking in account that the patient was on Anti-TB during the biopsy test. The patient was started on standard World Health Organization (WHO) multidrug therapy (MDT). After three weeks, he developed fever, arthritis, and tender supraorbital nodules consistent with Type II lepra reaction. He was managed with corticosteroids, physiotherapy, and continuation of MDT. Systemic symptoms subsided, though neurological deficits persisted. CONCLUSION: This case highlights the diagnostic challenges of PNL in the absence of skin lesions and the rare occurrence of Type II lepra reaction in this form. Early recognition, integration of advanced diagnostic tools, and timely physiotherapy are crucial to minimize disability in endemic settings.