Wool reaction?

When I react, it's either hives or a red dotted rash, kind of like prickly heat. . .

I'd guess that reactions vary by person. . . does your dc react to other things? Often I react to different skin irritants in a similar manner. . .

All 3 of my kids react with what looks like a heat rash. And it's only the area that directly touched the wool.

It's just weird, because he wore longies all winter with no skin problems. Now if I put him in a wool cover, he gets angry red spot around his thighs. It's upsetting, because I was planning on using wool through the summer, but I guess I'll have to figure something else out.

Could it be a chafing reaction, rather than a reaction to wool?