title: Potential use of the topical niacin skin test in early psychosis -- a combined approach using optical reflection spectroscopy and a descriptive rating scale.
abstract: The niacin skin phenomenon reflects a prostaglandin (PG) mediated flush and oedema reaction. As PG metabolism is linked to breakdown of membrane lipids, diminished sensitivity to niacin application suggests potential disturbance in membrane phospholipid-arachidonic acid-PG pathways. We aimed to evaluate and quantify topical niacin skin reaction in early psychosis using optical reflection spectroscopy (ORS) and a new descriptive assessment scale integrating time course, redness, and oedema. Niacin skin tests were performed on 25 medicated first-episode psychosis patients fulfilling DSM-IV criteria for schizophreniform psychosis or schizophrenia and on 25 healthy controls. Nicotinic acid was applied in four dilution steps to the subjects inner forearm skin and skin reaction was consecutively assessed using ORS and a seven point rating scale. Both descriptive ratings and spectroscopic measures revealed significant group differences at the lower niacin concentrations (0.001 and 0.0001 M). At higher concentrations (0.01 and 0.1 M) only descriptive ratings were capable to show significant group effects. Data of both methods showed moderate to strong correlation (r=0.605) as long as the erythema was not affected by the oedema. The data suggest that niacin sensitivity is inversely correlated with negative symptoms. Both methods demonstrate that niacin sensitivity is impaired in a group of first episode psychosis patients and are therefore able to distinguish a subgroup of patients with metabolic impairment. Niacin sensitivity in high risk populations and the specificity of impaired skin response are subjects of further investigation.
authors.affiliation: Department of Psychiatry, University of Jena, Philosophenweg 3, D-07743, Jena, Germany. smesny@web.de
authors.forename: Stefan
authors.initials: S
authors.lastname: Smesny
authors.forename: Gregor
authors.initials: G
authors.lastname: Berger
authors.forename: Timm
authors.initials: T
authors.lastname: Rosburg
authors.forename: Sven
authors.initials: S
authors.lastname: Riemann
authors.forename: Stefan
authors.initials: S
authors.lastname: Riehemann
authors.forename: Patrick
authors.initials: P
authors.lastname: McGorry
authors.forename: Heinrich
authors.initials: H
authors.lastname: Sauer
mesh_terms: D000287:Administration, Topical; D000293:Adolescent; D000328:Adult; D014150:Antipsychotic Agents / Q000627:therapeutic use; D039721:Diagnostic and Statistical Manual of Mental Disorders; D005260:Female; D006801:Humans; D008297:Male; D009525:Niacin / Q000008:administration & dosage; D055095:Optics and Photonics / Q000295:instrumentation; D011453:Prostaglandins / Q000502:physiology; D011618:Psychotic Disorders / Q000175:diagnosis* / Q000188:drug therapy / Q000503:physiopathology; D012882:Skin Tests; D013057:Spectrum Analysis / Q000295:instrumentation; D014665:Vasodilator Agents / Q000008:administration & dosage
chemical_list: D014150:Antipsychotic Agents; D011453:Prostaglandins; D014665:Vasodilator Agents; D009525:Niacin