Research

Allergic sensitisation in South Africa: Exploring regional variation in sensitisation

C van Rooyen, S van den Berg, P J Becker, R J Green

Abstract


Background. Allergy is a common health problem in South Africa (SA), and a rational approach to allergy testing is essential to ensure cost-effective as well as optimal patient diagnosis and management.

Objectives. To review allergy testing data with respect to current national testing recommendations, and to explore the regional variations in sensitisation.

Methods. Retrospective data review on allergy testing from a private pathology provider in SA over a 2-year period. Data on skin-prick testing (SPT) and allergen-specific IgE testing originating from all the provinces of SA were collected and analysed with regards to allergen positivity rate and regional sensitisation patterns.

Results. Among the patients (N=45 0320) tested for a suspected inhalant allergy, 46% tested positive. Only 45% of these received additional testing for the nine recommended inhalant allergens included in the current national testing protocol. Among the patients (N=6 775) who received SPT for a suspected inhalant allergy, 59% yielded one or more positive results. The most frequent sensitising allergens were house dust mite (Dermatophagoides pteronyssinus) and grass pollen. The house dust mite, Blomia tropicalis, was a significant sensitiser in coastal regions. SPT identified two other important regional allergens which are not included in the current recommendations for inhalant allergen-specific IgE testing.

Conclusions. The current diagnostic recommendations include allergens that demonstrate significant sensitisation in all regions of SA. Two additional allergens that show significant regional sensitisation in the South African population were identified. These findings may aid the recommendations for the most appropriate and cost-effective approach to allergy testing of symptomatic patients in SA.


Authors' affiliations

C van Rooyen, AMPATH Laboratories, Pretoria, South Africa; Department of Paediatrics and Child Health, Faculty of Health Sciences, University of Pretoria, South Africa

S van den Berg, AMPATH Laboratories, Pretoria, South Africa; Department of Paediatrics and Child Health, Faculty of Health Sciences, University of Pretoria, South Africa

P J Becker, Research Office, Faculty of Health Sciences, University of Pretoria, South Africa

R J Green, Department of Paediatrics and Child Health, Faculty of Health Sciences, University of Pretoria, South Africa

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Keywords

Allergic sensitisation; South Africa; Regional variation; Inhalant allergens; Maize pollen; Cockroach; D. pter-onyssinus; House dust mite; Grass pollen; Mould; A. alternata; Bermuda grass; Rye grass; Cat; Dog; Lipid transfer proteins; LTP; Profilin; PR-10

Cite this article

South African Medical Journal 2020;110(7):686-690. DOI:10.7196/SAMJ.2020.v110i7.14420

Article History

Date submitted: 2020-07-07
Date published: 2020-07-07

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