Abstract

A 34-year-old male of Indian origin presented with a 4-month history of bilateral sensory disturbance affecting the median nerve distribution and dorsum of both feet. Neurological examination was otherwise normal. A patchy absence of sensory responses was noted on nerve conduction studies and electromyogram (NCS/EMG). An interval re-assessment was arranged. However, over the next 3 months his sensory symptoms progressed to involve radial, ulnar, sural and peroneal nerves bilaterally. Repeat NCS/EMG confirmed a mononeuritis multiplex predominantly involving the sensory fascicles. The patient was admitted and was noted to have areas of hypopigmentation, a right lower motor facial weakness and ophthalmic branch trigeminal nerve involvement. The following investigations were negative or within normal limits: routine haematology, biochemistry, inflammatory markers, B12, folate, serum electrophoresis, hepatitis serology, HIV, serum ACE, and two autoimmune panels. MRI of the brain and spine, along with cerebrospinal fluid analysis, were also normal. Both punch skin biopsy and sural nerve biopsy demonstrated chronic granulomatous inflammation without evidence of Mycobacterium. A slit skin smear test demonstrated Mycobacterium leprae consistent with a diagnosis of primary neuritic leprosy. In the appropriate clinical context the differential diagnosis of mononeuritis multiplex should include leprosy.