Unusually massive ulnar nerve abscess in a leprosy patient; a diagnostic and therapeutic challenge

An 18 year old male on multibacillary multidrug therapy (MBMDT) for 7 months with the diagnosis of borderline tuberculoid (BT) leprosy, presented with gradually progressive and massive right ulnar nerve abscess and radial cutaneous nerve abscess. He also had mobile complete claw hand of the right side. High resolution ultrasonography (HR USG) of the right ulnar nerve showed markedly thickened ulnar nerve with loss of normal fascicular pattern. It also showed heteroechoic collection, with central anechoic lesion suggestive of ulnar abscess, measuring about 145cc in volume. In addition to MBMDT, the patient was started on tapering oral prednisolone starting 40 mg daily. The ulnar nerve abscess was decompressed by percutaneous aspiration on three occasions every 3-4 weeks. Serial HR USG of nerves was carried out throughout the treatment period. No surgical intervention was required. After 24 months of MBMDT, complete resolution of nerve abscess with improvement in right ulnar nerve motor function was noted. The patient underwent corrective surgery for right claw hand.