[Allergy in general practice in Arhus County. Quality assessment of diagnosis, treatment and instructions to patients. III. Allergy testing].
BACKGROUND
The aim of this study was to compare the allergy test with the skin prick test and the specific IgE by Phadiatop test to a purely clinical allergy diagnosis by an allergy specialist in adult patients previously tested in general practice.


METHODS
A total of 103 patients suspected of having asthma and/or rhinitis were re-evaluated with a clinical diagnosis and the two allergy tests. Both the patient and the individual general practitioner were asked about existing allergy diagnosis.


RESULTS
The two test systems showed large differences in a semiquantitative linear system with an explained variation (r2) of only 8%. In comparison to a purely clinical diagnosis, they were diagnostically equal with both tests, with an additional 15% positive reactions of which 25% were judged clinically active. Both tests resulted in about 33% false-positive tests classified as clinically inactive. In the case of a positive Phadiatop test and clinically active allergy, both the patient and the general practitioner reported identical specialist diagnoses in about 75% of cases, while in 20-50% of the cases an identical diagnosis was reported when the clinical diagnosis was qualitatively different from the result of Phadiatop.


CONCLUSIONS
The results of the two test systems often differ, and they both detect extra positive tests, in which case they should be used in a serial manner. Both tests often result in a false-positive diagnosis, and identification of clinically relevant positive tests often requires an experienced medical evaluation.
Jensen
Jens Korsgaard
JK
Arhus Universitetshospital, Aalborg Sygehus, Lungemedicinsk Afdeling E, Aalborg. j.korsgaard@dadlnet.dk
Jakobsen
Mogens Klitgaard
MK
D000328:Adult; D000485:Allergens / Q000627:therapeutic use; D003718:Denmark; D005194:Family Practice / Q000592:standards; D006801:Humans; D006967:Hypersensitivity / Q000175:diagnosis* / Q000188:drug therapy / Q000628:therapy; D006969:Hypersensitivity, Immediate / Q000175:diagnosis / Q000188:drug therapy / Q000628:therapy; D007073:Immunoglobulin E / Q000097:blood; D007407:Interviews as Topic; D010353:Patient Education as Topic / Q000592:standards; D012017:Referral and Consultation; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012882:Skin Tests / Q000592:standards; D011795:Surveys and Questionnaires
D000485:Allergens; D007073:Immunoglobulin E