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A 45-year-old man presented with subacute acral painful paresthesias with subsequent development of a persistent “awful” taste causing severe nausea and weight loss, a globus sensation causing coughing spells, heartburn, constipation, erectile dysfunction, and orthostatic syncope. He took no relevant medications and had no pertinent family history or exposures. He exhibited sluggish pupils and anisocoria, and lower extremity mild vibratory loss and allodynia. Autonomic testing revealed failure of sudomotor, cardiovagal and baroreceptor reflexes, and orthostatic hypotension. EMG/NCS was unremarkable. Skin biopsy showed length-dependent epidermal and sweat gland nerve fiber loss. Cerebrospinal fluid (CSF) protein was elevated. Evaluation for structural, infectious, neoplastic, autoimmune, toxic and metabolic etiologies was unrevealing. Syncope and constipation improved with pyridostigmine, but neuropathic pain and GI symptoms were refractory to pharmacologic intervention, and he eventually required a gastrostomy tube for long term nutrition. Autonomic testing improved after IVIg.

The subacute time course and elevated CSF protein suggest an immune-mediated SFSAN. While patients with autonomic neuropathies may develop GI symptoms due to gastrointestinal dysmotility and gastroesophageal reflux (GR), the refractory dysgeusia was considered out of proportion in this case. Isolated distorted taste perception has been reported in familial dysautonomia due to peripheral denervation of small sensory fibers. Additionally, dysgeusia and dysautonomia have been described in anti-glycine receptor encephalomyelitis. The prominent dysgeusia probably resulted from irritation of visceral afferent taste sensory fibers with some contribution from GR as a result of an inflammatory SFSAN.