How do bumps from a caterpillar sting last?

Bumps may form after a caterpillar has crawled on the skin. The bumps may go away after 3 to 5 days. If the bumps itch, a good home remedy is to apply any stick deodorant to the affected area when it starts to itch. A person should seek medical attention if the bumps appear in the form of blisters or turn a bright red.