Occurrence and distribution of peptidergic nerve fibers in skin biopsies from patients with systemic sclerosis.

Systemic sclerosis is characterized by vascular dysfunction. Itch is sometimes present in early stages of the disease. This prompted us to study the innervation of the skin by immunocytochemistry. Antibodies to neuropeptide Y and vasoactive intestinal peptide were used for autonomic nerves. Sensory innervation was studied using antibodies to substance P and calcitonin gene-related peptide. Protein gene product 9.5 was used as a general neuronal marker. Skin biopsies from affected (lower arm) and non-affected (upper back) sites on 10 patients with systemic sclerosis and from corresponding sites on 10 sex- and age-matched healthy controls were studied. Regional variations were found in the occurrence of peptidergic nerve fibers. In the patients the density of nerve fibers (measured semiquantitatively) stained by the panneuronal marker was lower in affected than in unaffected skin (p < 0.05). There were no significant differences in peptidergic innervation between patients and controls. However, there was a tendency to higher density of neuropeptide Y-positive nerve fibers in the forearm skin in 6 to 10 patients, as compared to only 1 of 10 healthy controls.