Invasive caterpillars causing Maine residents to break out in rashes

Caterpillars are taking over Maine — but they aren’t the kind you should befriend. Instead, these critters will leave you with painful rashes wherever they touch.

The state is experiencing an outbreak of the browntail moth caterpillar, an invasive species found on the coast of Maine and Cape Cod. They are easy to identify: They are about 1.5 inches long and dark brown, with white stripes along their sides and two orange dots on their back. 

Unfortunately, they are also hard to escape, being found in schools, parks, playgrounds, homes — and pretty much everywhere else. 

The hairs of the bug are poisonous and can cause a blistery rash, similar to poison ivy, upon contact with skin — which can occur from airborne hairs, not only from direct contact with the bug itself. These hairs can remain in the environment long after they’ve been shed from the insect’s body. 

If they are breathed in, the tiny hairs can also cause serious respiratory distress — a heightened concern during the coronavirus pandemic. Children and adults have been warned to avoid contact with them. 

The Maine Center for Disease Control and Prevention has declared the creepy crawlies a public health nuisance. There have been reports of more caterpillars than usual in the state since their active season began in April, and they have expanded to all 16 counties as the season reaches its peak. 

Health officials say that the majority of individuals affected by the hairs develop a localized rash, which can last from a few hours up to several days. For some who are more sensitive, the rash can be severe, lasting for several weeks.

The rash is a result not only of the barbed hairs embedding into the skin, but also from a chemical reaction to the poisonous toxin in the hairs. 

According to the Bangor Daily News, neighborhood Facebook groups have been dominated by discussions on the various ways to treat the rash in recent weeks. 

“We have had people coming in looking for remedies,” Christine Cattan, a pharmacist at Bangor Drug Company, told the newspaper. “It can be hard to diagnose just by looking because [the rash] kind of looks like prickly heat but it does have a characteristic mottled looking effect.”

Luckily, there are some easy ways to treat the rash, including ice packs, ibuprofen and topical creams. 

“Any sort of antihistamine will help,” Cattan said. “I also recommend people use a nice hydrocortisone cream with aloe to soothe the irritation.”

The risk of exposure to the hairs decreases after June but continues throughout the summer. 

According to the Maine Department of Agriculture, Conservation and Forestry, the caterpillars began pupating earlier this year than they typically do, likely due to a warmer spring. The silk cocoons surrounding these pupae contain the final skin of the caterpillars, meaning they are full of toxic hairs. 

“Generally speaking, this year will be as bad or worse than last year in terms of potential encounters with browntail moth,” officials at the department said. “Browntail moth populations in Maine have been in an outbreak phase since 2015, and populations last year continued to increase.” 

Several cities are now raising awareness on prevention methods, including changing clothes after outdoor activities, wearing a mask, goggles and coveralls when doing activities like yard work and drying laundry inside.