Athlete / Eleanor Archer.

An excellent and aspirational book about an athlete who has asthma, but manages it so that it doesn't interfere with her daily life and sport.
Age 8+

Charlie has asthma / Jenny Leigh

Simple story of Charlie the cheetah who is diagnosed with asthma and given advice and help to cope with it.
Age 5+

Zack has asthma / Jillian Powell.

Straightforward account of a child dealing positively with asthma.
Age 5+

Why is it so Hard to Breathe? - Pat Thomas

A basic introduction to asthma for children.  Reassuring in tone, it covers both the causes and how asthma is treated and managed.
Age 5+

When a book might help

Sharing stories about various situations can put a child’s mind at ease and make transitions and new experiences easier to cope with and more understandable.

Useful Organisation

Asthma UK
independent UK charity offering advice and support