Rash from condom?

My hubby and I used a condom for the first time in a while. We used the same brand from the same box a month or two ago and nothing happened, though not long into our session we decided it sucked and took it off lol. But this time he kept it on the whole time and got a small itchy rash on the head of his penis. I'm not sure if it's an allergic reaction or just friction. I know sometimes people can develop an allergy later in life and I'm wondering if maybe this happened, but I don't really know. Thoughts?