Evaluation of Skin Prick Test Reading Time at 10 versus 15 min in Young Infants

Int Arch Allergy Immunol. 2022;183(8):824-834. doi: 10.1159/000522526. Epub 2022 Mar 29.

Abstract

Introduction: The optimal time point for reading the mean wheal diameter (MWD) of a skin prick test (SPT) in infants is not established. We aimed to assess if either of two reading time points of the SPT, 10 or 15 min, was superior to detect allergic sensitization (AS) in 6-month-old infants.

Methods: In 1,431 6-month-old infants from the population-based Preventing Atopic Dermatitis and ALLergies in children (PreventADALL) mother-child cohort, the SPT was performed with standard solutions for egg, cow's milk, peanut, wheat, soy, birch, timothy, dog, and cat. The MWD was measured after 10 and 15 min. AS was defined as a positive SPT with MWD ≥2 mm larger than the negative control.

Results: Overall, 149 (10.4%) infants were sensitized to at least one allergen at 10 and/or 15 min, while 138 (9.6%) had a positive SPT at 10 min and 141 (9.9%) at 15 min. A total of 12,873 allergen pricks were performed with 212 (1.6%) being positive at any time point, 194 (1.5%) positive at 10 min, and 196 (1.5%) positive at 15 min. The mean (95% CI) histamine MWD of 3.8 (3.8, 3.9) mm at 10 min was significantly larger than the 3.6 (3.6, 3.7) mm at 15 min.

Discussion/conclusions: Reading the SPT after both 10 and 15 min increased the number of 6-month-old infants with documented AS compared to reading after one time point only. As neither 10 nor 15 min reading time was superior to the other in detecting AS, our results indicate that readings at both time points should be considered. However, the histamine MWD was significantly larger at 10 min compared to 15 min. Reappraisal of SPT reading in infancy may be warranted.

Keywords: Allergic sensitization; Infant; Mean wheal diameter; PreventADALL; Skin prick test.

MeSH terms

  • Allergens
  • Dermatitis, Atopic*
  • Histamine
  • Humans
  • Immunoglobulin E*
  • Infant
  • Skin Tests / methods

Substances

  • Allergens
  • Immunoglobulin E
  • Histamine

Grants and funding

This study is part of a PhD project within the University of Oslo, Norway. The PreventADALL trial was supported by a number of public and private funding bodies with no influence on the design, conduct, or analysis of the trial. The PreventADALL study has received funding from the following sources: South-Eastern Norway Regional Health Authority, the Research council of Norway, Oslo University Hospital, the University of Oslo, Health and Rehabilitation Norway, the Foundation for Healthcare and Allergy Research in Sweden − Vårdalstiftelsen, the Swedish Asthma and Allergy Association's Research Foundation, the Swedish Research Council − the Initiative for Clinical Therapy Research, the Swedish Heart-Lung Foundation, SFO-V Karolinska Institutet, Østfold Hospital Trust, the European Union (MeDALL project), by unrestricted grants from the Norwegian Association of Asthma and Allergy, the Kloster foundation, Thermo Fisher, Uppsala, Sweden (through supplying allergen reagents) and Fürst Medical Laboratory, Oslo, Norway (through performing IgE analyses), the Norwegian Society of Dermatology and Venerology, Arne Ingel's legat, Region Stockholm (ALF project and individual grants), Forte, Swedish Order of Freemasons Foundation Barnhuset, the Sven Jerring Foundation, the Hesselman Foundation, the Magnus Bergwall Foundation, the Konsul Th. C. Bergh's Foundation, the Swedish Society of Medicine, the King Gustaf V 80th Birthday Foundation, Karolinska Institutet grants, the Cancer and Allergy Foundation, the Pediatric Research Foundation at Astrid Lindgren Children's Hospital, the Samaritan Foundation for Pediatric research, the Children's Foundation at Oslo University Hospital, and the Nansen Foundation, Roche Norway. The authors have no financial relationships relevant to this article to disclose.