Standardization of the Prick Test

Abstract

The different needles and methods used in the prick test give rise to disparate results. This has significance when carrying out multi-centre studies and when using the technique in the standardization of allergenic extracts. With test reliability as our objective, prick tests were carried out on 30 subjects: 10 patients sensitive to Dermatophagoides pteronyssinus received a glycerine extract of known allergenic potency, 10 healthy individuals 2.5% codeine phosphate in a glycerine solution, and another 10, histamine 1/1000. The total prick tests per individual was 27 with each of the needles employed (Allergy Pricker, the Morrow-Brown needle and Insulin needle in accordance with Pepy's procedure). The tests were carried out systematically by three different testers, and the total number of prick tests performed was 810. With the Allergy Pricker, no differences were observed among results obtained by the same tester, nor when the results of the three testers were compared. With the Morrow-Brown needle, the results varied in the same person and from one tester to another, and on many occasions the test was negative. With the Pepys method, no falsely negative results were obtained, but there was considerable variation in the size of the wheal. The variation coefficient is 41% with the Allergy Pricker, and 115% and 64% with the Morrow-Brown and Pepys method, respectively. In conclusion, the results obtained clearly indicate that the highest degree of reproducibility is obtained with the Allergy Pricker.

Measuring atopy in a multi-centre epidemiological study

“…Results have been expressed as mean diameter [4], positive or negative, with positive defined as mean diameter/-> 3 mm [1,8,9] or > 0 mm [10], and as area [11]. Allergen wheal diameter greater than 0.4 of 3 mg/ml histamine dihydrochloride wheal diameter [12] has been advocated and allergen area adjusted for histamine and negative controls [13] has been investigated.…”

“…Any recommendations will not necessarily apply to all epidemiological studies as methods of skin prick testing change, and several studies have reported differing wheal sizes between methods [11,17]. Results from different methods may therefore not be directly comparable.…”

Identification of adults with symptoms suggestive of obstructive airways disease: Validation of a postal respiratory questionnaire

“…The investigations performed have been described in a previous study [5] and included forced expiratory volume in one second (FEV 1 ), forced vital capacity (FVC), FEV 1 / FVC, a peak expiratory flow diary, skin prick testing using the skin prick/puncture technique [6] and reversibility testing to β 2 agonists [7]. A bronchial challenge test to histamine was also performed by the YAN technique [8].…”

Identification of new minor metabolites of penicillin G in human serum by multiple‐stage tandem mass spectrometry

“…Hypersensitivity reactions to penicillins are due to different metabolite formed in vivo when the antibiotic is administered 13. After the administration of PCN G, the β‐lactam ring irreversibly opens during nucleophilic attack, resulting in the formation of penicilloyl metabolites and the covalent binding to tissue macromolecules to produce the hapten‐protein complex and induce immune response.…”