As advised, see your doctor sooner, instead of later. After radiation, my skin was sensitive, basically from the bridge of the nose to the collar bone, where the field of radiation was, so I rarely shaved, plus being no facial hair was growing for quite some time. Other skin products, sun, even foods can cause skin sensitivities after radiation, chemo and with certain medications too.

About 4 months after radiation, I developed shingles (herpes zoster), which is related to the chicken pox, so if you had that, one can be susceptible to it, especially with a lowered immune system, stress. Mine, a painful rash and blisters, started on the stomach, and then side and back. Some get it on the face too. Not saying that's what it is, but in such cases, it's best to treat it as soon as possible.

I hope your husband feels better!