Toddler chafing behind knees

[Mackemh]

Hi. My toddler starts to chafe behind her knees whenever the weather gets warm.
It doesn't seem to bother her, but it looks sore.

Does anyone have any recommendations for what I can buy to help with this (UK), or should I get something from the doctor?

Cheers.

How would she have chafed behind the knees? Surely this is eczema? If so then liberal application of moisturisers (4-5x daily) and see her GP to (a) confirm the diagnosis and (b) consider a steroid cream if it's quite bad or not settling.