Open AccessComparison between visual score and erythema index (DermaSpectrometer) in evaluation of allergic patch tests
Author(s) -
Held Elisabeth,
Lorentzen Henrik,
Agner Tove,
Menné Torkil
Publication year - 1998
Publication title -
skin research and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.521
H-Index - 69
eISSN - 1600-0846
pISSN - 0909-752X
DOI - 10.1111/j.1600-0846.1998.tb00108.x
Subject(s) - patch test , erythema , formaldehyde , spearman's rank correlation coefficient , medicine , allergy , dermatology , contact allergy , correlation coefficient , correlation , contact dermatitis , mathematics , chemistry , statistics , immunology , geometry , organic chemistry
Background/aims: During the last decade several new bioengineering methods have been proposed for evaluation of patch test reactions in a more objective manner. The aim of the present study was to investigate the usefulness of erythema index (DermaSpectrometer) in a clinical setting, i.e., reading of allergic patch tests. Methods: Twenty patients with known allergy to formaldehyde participated in the study. Each patient had patch tests for 2 days with formaldehyde solutions from 0 to 10,000 p.p.m. applied. Clinical reading of the test sites and measurement of the erythema index by the DermaSpectrometer were done 24 h after removal. A control group of 20 volunteers with no allergy to formaldehyde were tested in a similar way. Results: Erythema indices were significantly higher for visually rated positive patch tests than for negative tests ( P <0.05). The single categories of visually positive reactions (+?, +, ++, +++) could not be unambiguously separated by the DermaSpectrometer. The correlation between clinical readings and the formaldehyde concentration (Spearman's rank correlation coefficient, r =0.60) was higher than between DermaSpectrometer readings and the formaldehyde concentration ( r =0.35). Conclusion: In a dilution series of formaldehyde patch testing, readings from a DermaSpectrometer were not found to give better information than visual readings.