Cutaneous field stimulation of sensory nerve fibers reduces itch without affecting contact dermatitis.
BACKGROUND
A new technique, cutaneous field stimulation (CFS), which activates electrically unmyelinated C-fibers, is used to treat localized itch. Its action is similar to that of capsaicin, the pungent agent in hot peppers, which enhances delayed allergic reactions. The aim of the study was to investigate how experimental contact dermatitis responds to CFS.


METHODS
Twelve patients with contact dermatitis in response to nickel were treated by CFS for 1 h each for four consecutive days. A flexible plate containing electrodes was applied to a test area on the upper arm and was stimulated by a constant current (0.8 mA). On the fifth day, patients were provoked by epicutaneous application of nickel sulfate (allergic contact dermatitis) and benzalkonium chloride (irritant contact dermatitis), and by intradermal tuberculin (delayed immunologic reaction). Twelve other patients with IgE-mediated allergy were treated by CFS on the lower arm for 1 h and were then pricked with histamine and allergen extracts (wheal volume was measured) and were tested using benzoic acid (nonimmunologic contact urticaria; closed test). Ten of these patients were also treated by CFS for four days, and experiments were performed on the fifth day.


RESULTS
Test reactions to nickel, benzalkonium, and tuberculin were found to be unaffected by CFS treatment. Although allergic prick test reactions were enhanced (by 28%) after a single CFS treatment, the associated itch was significantly reduced both after single and repeated CFS treatments (by 65% and 38%, respectively).


CONCLUSIONS
Repeated use of CFS to reduce itch has no adverse effects on contact dermatitis.
Wallengren
J
J
Department of Dermatology, University Hospital, SE-221 85 Lund, Sweden.
D000279:Administration, Cutaneous; D000328:Adult; D000368:Aged; D000891:Anti-Infective Agents, Local / Q000009:adverse effects / Q000627:therapeutic use; D000935:Antifungal Agents / Q000009:adverse effects / Q000627:therapeutic use; D001548:Benzalkonium Compounds / Q000009:adverse effects / Q000627:therapeutic use; D019817:Benzoic Acid / Q000009:adverse effects / Q000627:therapeutic use; D003429:Cross Reactions / Q000187:drug effects; D017449:Dermatitis, Allergic Contact / Q000503:physiopathology* / Q000628:therapy*; D017453:Dermatitis, Irritant / Q000209:etiology; D003875:Drug Eruptions / Q000209:etiology; D004599:Electric Stimulation Therapy; D005260:Female; D006801:Humans; D006969:Hypersensitivity, Immediate / Q000503:physiopathology / Q000628:therapy; D008297:Male; D008875:Middle Aged; D009412:Nerve Fibers / Q000502:physiology*; D009532:Nickel / Q000009:adverse effects / Q000627:therapeutic use; D011537:Pruritus / Q000503:physiopathology* / Q000628:therapy*; D019275:Radiopharmaceuticals / Q000009:adverse effects / Q000627:therapeutic use; D011984:Sensory Receptor Cells / Q000502:physiology*; D012882:Skin Tests; D016896:Treatment Outcome; D014373:Tuberculin / Q000187:drug effects; D014581:Urticaria / Q000139:chemically induced
D000891:Anti-Infective Agents, Local; D000935:Antifungal Agents; D001548:Benzalkonium Compounds; D019275:Radiopharmaceuticals; D014373:Tuberculin; D009532:Nickel; D019817:Benzoic Acid