Dr Phil Kieran: My sporty teenager has an unusual summer rash

The pattern your son has doesn’t really fit with vitiligo, though, so the more likely culprit is pityriasis or tinea versicolor.

A one-off visit to the GP to confirm the diagnosis and get advice on preventing it would make sense. Picture: iStock 

For the second year in a row, my teenager has developed pale patches on his upper chest during the summer. It’s not itchy and becomes more obvious after he has been out in the sun and the surrounding skin tans. He’s a sporty boy, mostly playing soccer, and sweats heavily.

We will go through the two most likely conditions, neither of which is dangerous or worrying.