Intradermal positivity after negative prick testing for inhalants.
OBJECTIVE
Examine the incidence of positive intradermal tests after a negative skin prick test for 24 inhalant antigens.


METHODS
Retrospective study. Charts from patients who underwent modified quantitative testing (MQT) over a 3-year period were reviewed. Patients were initially tested with Multi-Test II. Subjects with negative wheals to a specific allergen were then tested with a 1:500 weight:volume intradermal injection of that allergen.


RESULTS
One hundred thirty-three patients underwent MQT for 24 antigens. Allergens with the highest incidence of positive intradermal wheals after negative prick testing were Dermatophagoides pteronyssinus and Dermatophagoides farinae at 26.67%. Allergens with elevated incidence of positive intradermals included fusarium, cockroach, cocklebur, rough marsh elder, and ragweed, all with incidences of 16% to 19%.


CONCLUSIONS
Positive intradermal responses after negative prick testing occur commonly. Future study is needed to determine the generalizability and clinical significance of these findings.


METHODS
C-4.
McKay
Shawn P
SP
Department of Otolaryngology-Head and Neck Surgery, Wayne State University, 4201 St. Antoine, Detroit, MI 48202, USA.
Meslemani
Danny
D
Stachler
Robert J
RJ
Krouse
John H
JH
D000465:Algorithms; D006801:Humans; D007428:Intradermal Tests; D012189:Retrospective Studies; D012882:Skin Tests