The Frequency of Irritant and Lost Reactions in the Standard Patch Test / 대한피부과학회지

ABSTRACT

BACKGROUND: The patcl test is widely used for diagnosis of allergic contact dermatitis. However, it is sometimes difficiilt or even impossihle to differentiate between allergic and irritant reactions in patch test readings. The achievernent of valid results from the patch test require intelligent and careful patch testing and physirians with skills and experiences. OBJECTIVE: The purpos of this study was to assess the frequency, age and sex distr ibution, and the seasonal variatioii of irritant. and lost reactions in standard patch tests. METHODS: Patch test records of day 2 and day 4 were reviewed and analysed. Frequency of inritant and lost reactions were analysed by allergen, age, sex and season. RESULTS: A total 212 c ses of standard patch test records(male 69, female 143) were analysed. The results were as follovs ; 1. The over all frequency of lost reactions in the standard patch test were 33.5 percents and that of irritant reactions were 8.0 percents. 2. The frequency of lost reactions was lower in the age groups under twenty(7.7%) than in the older age groups(35.5%). However, there was no significant difference between the age groups over the third dec ide. 3. The seasonal variation was evident in lost reactions. The order of frequency was summer(45.0% ), winter(33.7% ), spring and fall(2l.1% ). 4. The order of frequency of lost reactions in the stclndard patch allergen was captan(5.7%), potassium dichromate(5.2%), cobalt chloride(4.7%), mercury amrnoniurn chloride(3.8%) c3lld wool alcohol(3.8%). CONCLUSION: Our result, show a relatively high frequency of lost and irritant. reaction in the standird patch test, and uggest second readings in the patch test would he of value.