Etiological and clinical aspects of skin sensivity

Abstract

Rashes in dermatological disease are often accompanied by subjective symptoms, but in some cases the subjective symptoms are the most prominent signs of skin disorder. This is the case in "stinger patients", who may have an obvious skin disease, but in other cases there are no clear-cut reasons for the symptoms.

Thirty-two rosacea patients and 30 patients without obvious skin disease, but with subjective skin symptoms related to work with visual display units (VDU), and 32 skin-healthy control persons were double-blind tested with 5 % lactic acid and water (the "Stinger test"). The rosacea patients and those with VDU associated skin symptoms had significantly more subjective skin symptoms than did the control persons.

Twenty-four patients with VDU associated skin symptoms and 12 age- and sex-matched controls were subject to provocation by combinations of experimental stress and electric and magnetic fields. Stress provocation resulted in feelings of more intense mental stress and elevated heart rate, but no skin symptoms. The patients reported increased skin symptoms when they knew or believed that the electromagnetic field was turned on. Cells expressing SOM, CD1 a, TNF-alpha, or mast cells, in the skin, or stress-related hormones melatonin, prolactin, ACTH, NPY, and GH in blood were not affected by the stress exposure nor by exposure to electromagnetic fields. The results indicate that conditional effects may be of importance in inducing symptoms in patients with VDU associated skin symptoms.

Thirty-two patients with rosacea were treated with flashlamp pulsed dye laser focusing on effects on skin sensitivity, as well as neuromediator expression and nerve density using skin biopsies. Clinical investigations and "Stinger tests" were performed before and 3 months after the treatment. Thirty-one patients who were stinger positive before treatment showed decreased scores after treatment and only one patient had the same stinger score before and after treatment. The number of PGP 9.5 positive fibers in the epidermis and papillary dermis was decreased after the treatment. This was also the case for substance P in the papillary dermis as well as for VIP positive fibers, while no difference was noted for CGRP.

Twenty-five patients with atopic dermatitis, with a history of stress worsening, were investigated by biopsies from Stinger positive and negative areas from the nasolabial folds and processed for immunohistochemistry regarding nerve density, including axonal growth, expression of neuromediators and mast cells (tryptase positive). Sixteen patients (64%) were Stinger positive, while nine (36%) were negative. There was an increase in the number of VIP positive fibers and mast cells, and a tendency to an increased number of substance P positive fibers in the Stinger positive compared to the negative skin. In contrast, there was a decrease in the number of CGRP positive nerve fibers in the Stinger positive skin. There was a tendency to a lower salivary cortisol ratio in Stinger positive patients, indicating that the degree of chronic stress might be of importance.

Thus, patients with acne rosacea and atopic dermatitis are stingers, as well as subjects with symptoms when exposed to VDU. Nerve density, neuropeptides such as substance P, CGRP and VIP, and mast cells, may have an etiological role for the sensitive skin in these patients.