Leprosy is a caused by Mycobacterium leprae and affects mainly the skin and peripheral nerves. Cranial nerve neuropathy is common in patients with leprosy (~18%) and the trigeminal nerve is the second most affected.  However, there are very few reports showing trigeminal neuritis as the presenting symptom.

45 years-old male reported a dull right ear pain that lasted for 24 hours, which was followed by continuous shock-like and burning-like pain over the ipsilateral hemiface that worsened while chewing or tooth-brushing. Numbness was also reported and affected mainly the maxillary region. After medical evaluation, tooth-related pain was suspected, but no improvement was obtained after tooth extraction. He was also evaluated for temporomandibular joint dysfunction but it was also ruled out. He denied other clinical symptoms or disorders, as well as previous trauma or surgery involving the head or neck. Neurological examination was normal, apart from right-sided hypoesthesia over all trigeminal nerve divisions (especially V2). Brain Angio-MRI and laboratory workup were normal. He was diagnosed with atypical trigeminal neuralgia and carbamazepine was prescribed, with mild improvement. After two months, he started to present hemifacial swelling and erythema over V2 distribution, which worsened over a six-week period and spread to the jaw and left ear. He was referred to a Dermatology outpatient clinic and after a clinical evaluation, which included sensation tests, multibacillary leprosy was diagnosed. Auricular lesion biopsy revealed chronic granulomatous dermatitis and no bacilli was found. Treatment was started and great improved was obtained, despite persistent maxillary numbness.

Despite being rare, isolated neural involvement may be the presenting disorder in leprosy and, therefore, must be considered in patients with neuropathy of unknown etiology or with orofacial pain.