Skin wrinkling for diagnosing small fibre neuropathy: comparison with epidermal nerve density and sympathetic skin response.

OBJECTIVE

To compare simple tests of small nerve fibre function with intraepidermal nerve fibre density (IENFD) in the evaluation of small fibre neuropathy (SFN).

METHODS

Patients with idiopathic SFN of the hands were prospectively studied. Evaluation involved clinical examination, nerve conduction studies, sympathetic skin response (SSR) and skin wrinkling stimulated by water and EMLA (eutectic mixture of local anaesthetics).

RESULTS

Of 21 patients, 16 (76%) had low IENFD, 15 (71%) impaired water-induced wrinkling, 14 (67%) impaired EMLA-induced wrinkling, and nine (43%) abnormal SSR.

CONCLUSIONS

Stimulated skin wrinkling was nearly as sensitive as IENFD in diagnosing SFN, whereas SSR was of less use. Stimulated skin wrinkling is a useful supportive test when IENFD or other tests of small nerve fibre function are not available.