Contact dermatitis is inflammation of the skin caused by contact with a substance that causes an allergic reaction. Or it can occur from contact with a substance that irritates the skin. A minor case of contact dermatitis may cause mild redness of the skin or a rash of small red bumps, while a more severe reaction may cause swelling, redness, and larger blisters.
            A rash usually starts about 48 hours after exposure to the irritating substance. Common causes of contact dermatitis include:
            
              - Poisonous plants, such as poison ivy, oak, or sumac.
 
              - Soaps, detergents, shampoos, perfumes, cosmetics, or lotions.
 
              - Jewelry or fabrics.
 
              - New tools, toys, appliances, or other objects.
 
              - Latex gloves.
 
            
            The location of the rash may provide a clue about the cause.
           
         
        
          
            
              Current as of: December 4, 2024