BACKGROUND: The skin prick test is the diagnostic procedure of choice for determination of immediate hypersensitivity. A wheal diameter of 3 mm or larger is generally accepted as the cutoff for a positive test result, although the validity of this assumption has not been rigorously demonstrated. OBJECTIVE: To determine the skin prick wheal size that best identifies clinical allergy to cat. METHODS: Forty-five patients referred for evaluation of rhinoconjunctivitis underwent determination of atopic status by skin testing using the Greer Dermapik device and a combination of other modalities, including history, in vitro determination of specific IgE level, and nasal challenge with standardized cat pelt extract. Parameters evaluated before and after nasal challenge included symptom score and nasal lavage tryptase and prostaglandin D (PGD2) levels. RESULTS: The widely accepted 3-mm wheal for a positive skin test result to cat is highly sensitive but only moderately specific for diagnosis of cat allergy as evaluated by history, specific IgE level, postchallenge symptom score, and tryptase and PGD2 levels. Optimal cutoffs for a positive skin test result to cat based on receiver operating characteristic analysis and 95% positive predictive value were 5.5 mm or greater for each of these parameters. When a true-positive result for cat allergy was defined as a combination of positive history, specific IgE level, postchallenge symptom score, and tryptase and PGD2 levels and a true-negative result as all of these parameters being negative, a 6-mm cutoff was able to distinguish cat allergic from cat nonallergic individuals. CONCLUSION: In a potentially allergic population undergoing skin prick testing with the Greer Dermapik using standardized extracts, a 3-mm skin prick wheal will overestimate the presence of cat allergy. A 6-mm wheal appears to distinguish those individuals who are cat allergic from those who are not.
BACKGROUND: The skin prick test is the diagnostic procedure of choice for determination of immediate hypersensitivity. A wheal diameter of 3 mm or larger is generally accepted as the cutoff for a positive test result, although the validity of this assumption has not been rigorously demonstrated. OBJECTIVE: To determine the skin prick wheal size that best identifies clinical allergy to cat. METHODS: Forty-five patients referred for evaluation of rhinoconjunctivitis underwent determination of atopic status by skin testing using the Greer Dermapik device and a combination of other modalities, including history, in vitro determination of specific IgE level, and nasal challenge with standardized cat pelt extract. Parameters evaluated before and after nasal challenge included symptom score and nasal lavage tryptase and prostaglandin D (PGD2) levels. RESULTS: The widely accepted 3-mm wheal for a positive skin test result to cat is highly sensitive but only moderately specific for diagnosis of cat allergy as evaluated by history, specific IgE level, postchallenge symptom score, and tryptase and PGD2 levels. Optimal cutoffs for a positive skin test result to cat based on receiver operating characteristic analysis and 95% positive predictive value were 5.5 mm or greater for each of these parameters. When a true-positive result for cat allergy was defined as a combination of positive history, specific IgE level, postchallenge symptom score, and tryptase and PGD2 levels and a true-negative result as all of these parameters being negative, a 6-mm cutoff was able to distinguish cat allergic from cat nonallergic individuals. CONCLUSION: In a potentially allergic population undergoing skin prick testing with the Greer Dermapik using standardized extracts, a 3-mm skin prick wheal will overestimate the presence of cat allergy. A 6-mm wheal appears to distinguish those individuals who are cat allergic from those who are not.
Authors: Sarah K Wise; Sandra Y Lin; Elina Toskala; Richard R Orlandi; Cezmi A Akdis; Jeremiah A Alt; Antoine Azar; Fuad M Baroody; Claus Bachert; G Walter Canonica; Thomas Chacko; Cemal Cingi; Giorgio Ciprandi; Jacquelynne Corey; Linda S Cox; Peter Socrates Creticos; Adnan Custovic; Cecelia Damask; Adam DeConde; John M DelGaudio; Charles S Ebert; Jean Anderson Eloy; Carrie E Flanagan; Wytske J Fokkens; Christine Franzese; Jan Gosepath; Ashleigh Halderman; Robert G Hamilton; Hans Jürgen Hoffman; Jens M Hohlfeld; Steven M Houser; Peter H Hwang; Cristoforo Incorvaia; Deborah Jarvis; Ayesha N Khalid; Maritta Kilpeläinen; Todd T Kingdom; Helene Krouse; Desiree Larenas-Linnemann; Adrienne M Laury; Stella E Lee; Joshua M Levy; Amber U Luong; Bradley F Marple; Edward D McCoul; K Christopher McMains; Erik Melén; James W Mims; Gianna Moscato; Joaquim Mullol; Harold S Nelson; Monica Patadia; Ruby Pawankar; Oliver Pfaar; Michael P Platt; William Reisacher; Carmen Rondón; Luke Rudmik; Matthew Ryan; Joaquin Sastre; Rodney J Schlosser; Russell A Settipane; Hemant P Sharma; Aziz Sheikh; Timothy L Smith; Pongsakorn Tantilipikorn; Jody R Tversky; Maria C Veling; De Yun Wang; Marit Westman; Magnus Wickman; Mark Zacharek Journal: Int Forum Allergy Rhinol Date: 2018-02 Impact factor: 3.858
Authors: Cynthia A Esteban; Robin S Everhart; Sheryl J Kopel; Robert B Klein; Daphne Koinis-Mitchell Journal: Ann Allergy Asthma Immunol Date: 2017-09 Impact factor: 6.347
Authors: Abena S Amoah; Benedicta B Obeng; Irene A Larbi; Serge A Versteeg; Yvonne Aryeetey; Jaap H Akkerdaas; Laurian Zuidmeer; Jonas Lidholm; Montserrat Fernández-Rivas; Franca C Hartgers; Daniel A Boakye; Ronald van Ree; Maria Yazdanbakhsh Journal: J Allergy Clin Immunol Date: 2013-06-12 Impact factor: 10.793