When the skin seems to get away from you... that is --always has some irritation---it might be a good idea to look at nutrients that support the skin.
Low zinc will result in irritations becoming infected.
Low biotin will also damage the skin.
Low omega-3 fatty acids in the diet, will affect skin because they repair cell membranes.
There are always organisms on the skin. But a good barrier, keeps them from becoming pathogenic and infecting you.
People with poor glucose control also get fungal infections easily.
Biotin doses would start at 5mg or so daily. Biotin is very benign with no reported side effects. Most supplements are in the microgram range, but I'd try higher doses to see if you are in need of it for some reason.
Zinc can be depleted from the body by drugs. The most common are ACE inhibitors, and acid blocking drugs for heartburn. OptiZinc is the most easily tolerated zinc and not expensive. One a day is typically enough for most people.
Omega-3s can be in food now, many foods have them added now. Or you can get a quality fish oil, or krill oil and take 2 of them daily. Take with food. This can really help with skin issues.
Welting from pressure is considered an allergic response.
http://dermatology.about.com/cs/hives/a/pressurt.htm
If you have this in other body areas in response to pressure...it would be a good idea to see a dermatologist.