Value of thyroid and rheumatologic studies in the evaluation of peripheral neuropathy.

Peripheral neuropathy is a common disorder, often prompting an extensive initial laboratory evaluation. The initial evaluation is particularly challenging to primary care physicians and neurologists because of the broad differential diagnosis. Although screening thyroid and rheumatologic tests are frequently ordered, the diagnostic yield of these tests is unclear. Data from our institution were collected on patient demographics, clinical characteristics including warning signs suggestive of a diagnosis other than distal symmetric polyneuropathy, history of thyroid or rheumatologic disease, and laboratory tests ordered. Thyroid and rheumatologic screening tests are commonly ordered in the evaluation of peripheral neuropathy. Our findings suggest a low aggregate value of these tests based on low yield and infrequent changes in the suspected etiology or management of these patients.