risk of urticaria with use of Aquafour

I am currently receiving radiation treatments. My skin is very sensitive. My doctor is concerned about risk of urticaria if I use Aquafour, however, Aquafour is the only thing which has relieved the burning sensation.  If I was going to get urticaria would it occur right away or only after prolonged use

[maatson]

I do not think Aquaphor would sensitize you with an urticaria in realistic terms.
Best wishes.