My 1yr old has a strange, red, raised scratch like mark on the back of his neck for a week + now. it's not going away and gets more red if he gets hot. pharmacy nurse said his 1 gland by his ear is slightly enlarged. not itchy, no apparent pain?

Allergy or heat rash: It seems a benign rash. One year old kid won't complain itchy, I assume. It is not typical as heat rash but I am more suspecting of an allergic reaction with something new he wears. Does he wear a new bib, give example? You can try hydrocortisone cream or ointment (over the counter), twice a day for a couple days. If it goes away, it is likely a form of contact dermatitis (allergic rash).