Usage patterns
〈場所〉に湿疹ができるa rash/eczema develops on (a part of the body)
I got a rash on my arm and it's itchy.
湿疹が出るa rash breaks out
I break out in a rash when I use this cosmetic.
湿疹が悪化するthe rash worsens
The rash got worse after I stopped applying the medicine.
湿疹を治すto cure/treat a rash
I had my rash treated at a dermatology clinic.
湿疹をかくto scratch a rash
I ended up scratching the rash, which made it even redder.