Abstract
We report two sarcoidosis cases complicated with small fiber neuropathy. Two female patients, 71-years-old and 67-years-old, were referred to our institute, complaining of paresthesia in their extremities. Neurological examinations revealed moderate impairment of senses of warmth and pain in their distals, but no impairment in touch, joint and vibration sensation. Hypohydrosis and constipation were seen in both patients. Nerve conduction and needle electromyogram studies were normal These results were compatible with small fiber neuropathy. Immunostaining of skin biopsy specimen revealed a significant decrease in epidermal nerve fiber density, and significant increase of axonal damage. From these findings, the two cases were definitely diagnosed as having small fiber neuropathy. Diclofenac and mexiletine hydrochloride relieved paresthesia to some extent in Case 1, and amitriptyline hydrochloride was effective in Case 2.
Peripheral nerve impairment in sarcoidosis has so far been commonly thought to be represented by cranial nerve palsy and mononeutitis multiplex, but our cases suggest that small fiber neuropathy is more frequently seen among sarcoidosis patients than previously thought. Nerve conduction study and skin biopsy are useful in the diagnosis of small fiber neuropathy among a wider variation of neuropathies with sarcoidosis.
