What are the symptoms? An itchy discharge from your ear.
What causes it? This is an infection. It results from you marinading your ears in pool or sea water, then baking them in sunshine.
How can I treat it? Prevention is important because it tends to recur. Keep water out of your ears; use earplugs when you swim. And don't be tempted to ease the symptoms by prodding about with a cotton bud as it will only make matters worse. If it doesn't settle down, it'll need treatment with drops or a spray containing anti-inflammatories and antibiotics. See your GP.
Juvenile spring eruption
What are the symptoms?
This mainly affects young boys and causes sore swellings, blisters or crusts on the ears, usually a day or two after exposure to the sun. Typically, it appears in spring or early summer and may recur.
What causes it?
It's an unusual sensitivity to sunshine. Boys are more affected because their shorter hair does not shade their ears from the sun.
How can I treat it? Sunscreens and hats will shield the sensitive ear skin. So, too, will long hair - this may be a good excuse for your son to adopt that hairstyle he has always wanted. Any cooling cream will help the rash.