Common indoor and outdoor aero-allergens in South Africa

Abstract

Identification of the allergen responsible for symptoms is the key to the management of the allergic patient. It is important that every practitioner should be familiar with the common allergens in South Africa to make a specific allergy diagnosis in such patients.

South Africa, because of its wide range of ecological biomes, is home to most of the common indoor and outdoor aero allergens recognised globally. It also has a number of indigenous grass, tree and insect allergens which appear to be “unique” to the African region.

Exposure to aero allergens may be indoor or outdoor, during every day life, via the inhalant, ingestant or cutaneous routes, but may also occur in an occupational environment.

Aero allergens of South Africa, which are also encountered around the world, are listed in Table 1. In addition to such a wide range of common aero allergens, South Africans are also exposed to full range of food allergens, some of which, e.g. Perlemoen (Haliotis midae) and other seafood allergens are unique to the region, but some may be encountered as accordingly during food processing. The review will focus on the common aero allergens of South Africa.

Most of the common allergens to inhalants may be diagnosed using commercial allergy skin tests or ImmunoCAP RAST tests, but specific diagnosis of novel or unique allergies previously unrecognised, may be performed by specialist allergy centres, with facilities for titrated skin prick testing with fresh extracts, or using Western blotting or basophil histamine release test in the laboratory.