Approach to the evaluation of small fiber peripheral neuropathy and disorders of orthostatic intolerance

Small fiber peripheral neuropathy is a frequently encountered neurological disorder, which can be difficult to diagnose. In this article, the differential diagnosis of small fiber neuropathy is discussed, along with role of autonomic testing, skin biopsy, and quantitative sensory testing, in establishing a definitive diagnosis of small fiber peripheral neuropathy. Disorders of orthostatic intolerance, including postural orthostatic tachycardia syndrome (POTS), are also discussed, emphasizing diagnostic evaluation and a treatment approach to these disorders.