Let's talk rashes! He's my second baby but never experienced a localized rash other than diaper rash on a baby before (my daughter had hives before but this is so different). Any ideas? No fever and no other rashes on his body and it doesn't seem to both him. Could it be a food allergy? I just always assumed those allergies were more widespread than one spot (on the back of his thigh). Seems so random!

(He's 10 months so he hasn't had a vaccine since 6 months old and this started to appear about two weeks ago. I've been putting desitin on it but likely need to change to something else). Any advice? TIA!

Same pic just one with and without the flash on.