The venomous puss moth caterpillar (Megalopyge opercularis; also called the asp) is present in the southern United States. It is teardrop shaped and has long silky hair, making it resemble a tuft of cotton or fur.
When a puss moth caterpillar rubs or is pressed against a person’s skin, its venomous hairs are embedded, usually causing severe burning and a rash. Pain usually subsides in about an hour.
Occasionally, the reaction is more severe, causing swelling, nausea, and difficulty breathing.
(See also Introduction to Bites and Stings.)
Treatment
- Relief of pain
Several techniques may soothe the pain and burning caused by puss moth caterpillar stings.
- Washing the sting with soap and water and using a hair dryer set on low to dry the area
- Putting tape on the site and pulling it off to remove embedded hairs to prevent further injury
- Applying isopropyl alcohol (rubbing alcohol) to the sting
- Applying a baking soda slurry
- Applying calamine lotion
- Placing an ice pack or an ice cube wrapped in plastic and a thin cloth over the sting
More severe reactions require immediate medical attention.
