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Hives and Caterpillars

by Lora Stewart, MD


There are certain types of insects that can cause allergic reactions.  Most people know about bees and fire ants, but there is a caterpillar that can cause allergic reactions too.

The Douglas-fir Tussock Moth caterpillar is covered with small hairs which may cause allergic reactions in some people and some pets.  The typical reaction includes rash, hives, redness and itching of the skin, sneezing, runny nose and watery eyes.  The reaction is called “Tussockosis”.   The caterpillars must touch your skin in order to cause the allergic reaction, it is not airborne.

Douglas County currently has high levels of tussock moths and caterpillars.  The Douglas-fir tussock moth caterpillars are a native species that primarily feed on Douglas fir needles. According to the Douglas county website, the current tussock moth caterpillar activity is occurring on both private and US Forest Service lands between Perry Park and Valley Park, areas off Dakan Road and west of Pine Creek Road.

Preventative measures include:

  • Avoid spending time in infested areas

  • Avoid touching the caterpillars

  • Wear long sleeves, long pants and gloves

  • Wash exposed skin immediately with soap and water

  • Shower and change clothes after spending time in an infested area

  • If rash occurs, treat with Over-The-Counter anti-itch creams and anti-histamines.

If the rash is significant or the medications are not working, contact our office.

Contact us with any questions or concerns, and have a fun and safe summer!