SECONDARY PREVENTION OF ASTHMA: IS THIS POSSIBLE WITH ENVIRONMENTAL CONTROL, PHARMACOTHERAPY OR IMMUNOTHERAPY?

Asthma is common and to a large extent it has no cure. Children with a family history of atopy and those with a history of allergic diseases such as eczema, food allergy and allergic rhinitis are at increased risk of developing asthma. The prevention of asthma in such high-risk cases (secondary prevention of asthma) has been explored from three angles: environmental control, pharmacotherapy and specific allergen immunotherapy, all of which are discussed in this article. Pharmacotherapy in high-risk infants has produced largely disappointing results. General advice on the reduction of exposure to tobacco smoke and to outdoor and indoor pollution should be heeded. Excellent control of co-existent atopic conditions such as eczema may reduce progression to associated respiratory allergic conditions. Robust evidence now indicates that allergen-specific immunotherapy can prevent the development of asthma in children with moderate-to-severe allergic rhinitis and pollen allergy up to two years post immunotherapy, and perhaps even longer. Poor availability and the high cost of immunotherapy currently hamper its widespread use in South Africa.