What factors may have triggered this asthmatic episode?

-" infections, usually those caused by a virus (e.g. colds or flu)

allergens, most commonly from house dust mites, pets or pollen

exercise, especially in cold weather

emotions, such as excitement, fear or anger

irritants, such as air pollution

smoking people with asthma and the parents of asthmatic children should avoid smoking

changes in the weather (e.g. a cold spell)

food additives, such as tartrazine (an artificial food colouring), or food allergens, such as peanuts (sensitised or allergic individuals can have a very severe allergic reaction).

certain medications some people may be allergic to some drugs (e.g. aspirin"