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Delayed patch test reactions at days 7 and 9
Author(s) -
MacFarlane A. W.,
Curley Regina K.,
Graham R. M.,
LewisJones M. Susan,
King Clodagh M.
Publication year - 1989
Publication title -
contact dermatitis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.524
H-Index - 96
eISSN - 1600-0536
pISSN - 0105-1873
DOI - 10.1111/j.1600-0536.1989.tb03121.x
Subject(s) - patch test , potassium dichromate , medicine , patch testing , sensitization , contact dermatitis , dermatology , surgery , anesthesia , allergy , immunology , chemistry , organic chemistry
403 consecutive patients were examined on days 2, 4, 7, and 9 following application of patch tests. Late positive reactions, i.e., those which manifested after day 4, were seen in 29 patients (7.2%). The allergens which most commonly produced late positive reactions were neomycin (7), potassium dichromate (4), and cobalt (3). Paired patch test readings on days 4 and 7 were more reliable than those on days 2 and 4. If only 1 patch test reading were performed, a single reading on day 4 would have been most useful. The reading on day 9 proved to be of limited value. Of 11 patients who were retested after an interval of more than 6 months, 7 showed earlier eliciting reactions, which may have been due to active sensitization.