Rash on 1yo neck

[PassTheAfterEights]

Just found this drying off after the bath in the folds of DS neck on one side - doesn't look like anything I've ever seen before and really hoping it is a side effect rash of his 1yo jabs which we had 3 days ago, not sure if it matches the description on the jab leaflets though, any advice would be gratefully received. Sorry photos are not great, hard to hold him still. Will obviously get to the gp ASAP. Tia.

Has any milk for trapped in the folds? Or sweat?

It looks a bit like a heat rash. Has he been sweaty and warm in these warm temperatures lately? That said, it’s totally possible it could be related to jabs. My youngest had a horrendous reaction to his 1 year jabs. He got irritable hip syndrome, which is basically them their joints become really inflamed and painful. I spent 2 nights sitting up awake in the chair holding him because he screamed in pain anytime I tried to lie him down. He also couldn’t crawl for about 4 days. He just completely lost the use of his legs. He was absolutely fine once the inflammation cleared up, but they had have really varied reactions.

Thanks both so much. Yes he's been warm (we're in Edinburgh but even here it's been a toasty couple of weeks) and had a raging fever Friday night through yesterday from the jabs and very sweaty at night. So hopefully that explains it. He's cooled down - so has the weather! - so I'll keep it dry and keep an eye on it. Really grateful for your help.

And @mindutopia really sorry to read about your poor bb's experience, how awful - must have been a big worry at the time. Hope it never recurs!