Your child may be allergic to nickel.
Some children develop an allergy to nickel. When your child’s bare skin rubs against snaps, buttons, or even a belt, nickel can leach out and irritate the skin. Nickel is a very common cause of allergic contact dermatitis, occurring in nearly 10 percent of the population.
Your doctor may advise a low potency steroid cream to apply to the rash. If the rash is very itchy, talk to your doctor about an over-the-counter antihistamine, such as Benadryl, to make your child more comfortable. With treatment, the rash should clear up within a couple of weeks.
The only way to keep the rash from returning is to avoid the nickel. Be sure to get rid of that new belt your little one started wearing right before the rash developed. You could also try applying clear nail polish or Scotch tape to the back of the buttons or snaps so they are not in direct contact with the skin.
Reviewed by Dr. Sara Connolly, April 2019