Prick tests to aeroallergens: is it possible simply to wipe the device between tests?
BACKGROUND
Improperly performed skin prick tests (SPT) can lead to wrong allergy diagnosis and incorrect treatment. To overcome false-positive results it is recommended to change the puncture device between each test, although very few studies have examined the real drawbacks (false-positives) and advantages (time and cost savings) of using only one device.


METHODS
Two groups of 20 patients with rhinitis or asthma, sensitized to either house-dust mites or grass pollens, had successive serial SPT to 9% codeine phosphate and the relevant allergen using the same needle or lancet, wiped between each test.


RESULTS
With both the needle and the lancet, there were 12.5-67.5% false-positive results using the house-dust mite or grass pollen allergen extracts, respectively. There were no false-positive results with the 9% codeine phosphate.


CONCLUSIONS
Our study shows that this technique is not reliable as it provoked an unacceptable number of false-positive results.
Piette
V
V
Maladies Respiratoires, INSERM U454-IFR3, Hôpital Arnaud de Villeneuve, CHU de Montpellier, France.
Bourret
E
E
Bousquet
J
J
Demoly
P
P
D000293:Adolescent; D000328:Adult; D000393:Air Pollutants / Q000276:immunology*; D000485:Allergens / Q000032:analysis*; D039741:Antigens, Dermatophagoides / Q000032:analysis*; D060829:Arthropod Proteins; D003546:Cysteine Endopeptidases; D003951:Diagnostic Errors; D004869:Equipment Safety; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012882:Skin Tests; D014783:Viscosity
D000393:Air Pollutants; D000485:Allergens; D039741:Antigens, Dermatophagoides; D060829:Arthropod Proteins; D003546:Cysteine Endopeptidases; C451162:Dermatophagoides pteronyssinus antigen p 1