Some children with asthma only wheeze when they have a cold or upper respiratory infection. This is considered a lifelong condition, but the frequency and severity of symptoms may change as your child gets older.

A combination of genetics and environmental factors can cause your child to develop seasonal allergies. While you can't change your child's genetics, you can reduce or delay your child's reactions and symptoms by minimizing exposure to triggers.

Substances that cause allergies in 3-4 year olds include foods, medicines, animal hair, dust mites, molds and pollen, etc. Children 3 years old often have allergies with symptoms related to the respiratory tract (allergic rhinitis), skin (eczema) or intestinal problems (food allergies).