Concordance between epidermal nerve fiber density and sensory examination in patients with symptoms of idiopathic small fiber neuropathy

Quantitation of epidermal nerve fiber (ENF) density is an objective diagnostic test of small fiber neuropathy (SFN). For a diagnostic test to be clinically useful it should correspond well with clinically meaningful physical findings. We performed a retrospective analysis of the concordance between foot ENF density and clinical findings in all patients seen at our institution with possible idiopathic SFN who underwent skin biopsy for ENF density determination. We found a high concordance between reduced foot ENF density and loss of pinprick sensitivity in this patient population. Our findings indicate that ENF density determination is a clinically relevant objective test in patients undergoing evaluation for possible SFN.