What can i use to treat a sunburn-like, itchy rash?

Aloe: You can start by trying aloe and supplementing with Benadryl (diphenhydramine) as needed for the anti-histamine effect and itching. If severe, se your dr. Use spf at least 15 or greater as prolonged sun exposure is a risk factor over time for skin cancer. Best wishes.

See a dermatologist: Get a diagnosis. Aloe will do no more than any other lubricant. Benadryl (diphenhydramine) will not help your itch. Be careful of benadryl: it is a sleeping pill which should only be used at bedtime. Meanwhile try Hydrocortisone cream.