One in five children in the UK suffers from dry skin and eczema. Atopic eczema is the most common type of eczema in children. Thought to run in families, it can begin in babies from six weeks old and continue throughout childhood. Approximately two thirds of children will have 'grown out' of eczema by puberty.
Triggers for flare-ups in children are similar to those of adults, but you might want to watch out for the following too:
Stress is a trigger, so keep an eye on your child's emotional state, particularly relating to stressful periods such as exam time at school.
Sources
http://www.nhs.uk/Conditions/Eczema-(atopic)/Pages/Introduction.aspx (last accessed May 2010)