To assess the sensitivity, specificity, and predictive value of pinprick perception and its concordance with established laboratory measures in small fiber neuropathy.
Fifty-six patients suspected of SFN underwent detailed evaluation and standardized quantitative sensory and autonomic testing. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value of pinprick sensation were determined.
Pinprick perception had relatively consistent results between modalities with moderate sensitivity (70%); combining the testing modalities increased the diagnostic yield. PPV of pinprick approached 89%; however, negative predictive value was 19%.
As a screening tool, pinprick has high PPV for SFN, but many patients are likely to be missed if they report unimpaired subjective perception of pinprick sensation. Multimodal testing is recommended in clinically suspected cases to positively rule out SFN.