How To Treat Browntail Moth Rash: Relief and Prevention
You may already be familiar with threatening browntail moth caterpillars, especially if you live in the northeastern US. Found primarily on the coast of Maine and Cape Cod, the dangers of browntail moth caterpillars are two-fold: They cause skin rashes and also feed on trees to the point of killing them. Due to their seasonal resurgence, this bothersome creature is receiving lots of attention lately. As the weather warms and people begin heading outdoors, browntail moth caterpillars are also emerging from their webs in the trees. For information on when and where to spot them, how to treat a browntail moth rash, and how to prevent your plant life from being destroyed, keep reading.
Quick Reference: Browntail Moth Rash
- What causes it: tiny barbed, toxic hairs from browntail moth caterpillars (Euproctis chrysorrhoea), found mainly along the coast of Maine and on Cape Cod.
- First aid: wash your clothes and take a cool shower right away, then use Benadryl or hydrocortisone cream on the itchy, blistered, poison-ivy-like rash.
- Highest risk: April through July, when caterpillars are in their third larval stage. The toxin can stay active in the environment for one to three years.
- See a doctor if: you have trouble breathing after exposure, which can follow inhaling the hairs.
- Remove webs: clip winter webs between October and mid-April, before the caterpillars emerge.
If you live in the northeastern United States, you may already know the browntail moth caterpillar by its sting. Found mainly along the coast of Maine and on Cape Cod, this small caterpillar carries a double trouble: its barbed hairs raise an itchy, poison-ivy-like rash on people, and its appetite can strip the leaves off a tree. As the weather warms each spring and folks head back outdoors, the caterpillars come out of their webs in the treetops right alongside us. Here is how to treat a browntail moth rash, how to spot the culprit, and how to keep your yard and trees out of harm’s way.
Treating Browntail Moth Rash
If you brush up against the stinging hairs of a browntail moth caterpillar while walking in the woods, wash your clothes and take a cool shower as soon as you can. A few hours later you may notice a rash much like the one poison ivy leaves: itchy, blistered, and swollen skin. Most people get a localized rash that lasts anywhere from a few hours to several days. Folks with more sensitive skin can get a more severe rash that lingers up to several weeks. Take Benadryl or dab hydrocortisone cream on the area to ease the symptoms. You can also reach for a bar of our Poison Ivy Soap, which calms browntail moth rashes just as well. If you are looking for more soothing options, our roundup of poison ivy remedies and prevention tips applies to this rash too.
One symptom calls for more than home care. Trouble breathing is possible after exposure, especially if the hairs are inhaled, and it can lead to more serious problems. If you are having trouble breathing, seek medical attention immediately. The Maine Forest Service, which tracks the insect closely, keeps an up-to-date browntail moth fact sheet with current guidance for residents in affected towns.
When And How To Spot Them
The greatest risk of exposure to these tiny toxic caterpillars runs between April and July, when they are in their third larval stage. The toxin does not leave with them, though. It can stay stable in the environment for one to three years and may turn airborne again if something stirs it up.
Browntail moth caterpillars have a dark brown body with a segmented white stripe running down each side and two noticeable red spots on the back. Younger caterpillars may not show the white stripes yet. Their bodies grow to about 1.5 inches long and are covered in toxic, barbed hairs.
Adult browntail moths have snow white wings, a wingspan of roughly 1.5 inches, and a tuft of dark-brown hair on the tip of the abdomen, which is how the moth earned its name. That brown tip sets it apart from the similar Yellow-tail moth, which carries a yellow tip instead. The adults fly at night during July and August and are strongly drawn to light, especially between 10 p.m. and 2 a.m. The adult moths themselves are not dangerous, since their hair is not toxic. Still, if you spot the adults, there is a good chance their caterpillars are nearby, so keep watch and take precautions.
Browntail Moth Caterpillar Look-a-likes
Browntail moth caterpillars are often confused with their long brown-haired look-a-likes, the Eastern Tent and Gypsy caterpillars. Here is how to tell them apart. The browntail moth caterpillar has white tufts running alongside its body. The Eastern Tent caterpillar instead has a white stripe down the center of its back, with blue spots that look like the “eye” in a peacock feather along each side of the stripe. The gypsy moth caterpillar has prominent knobs with hairs on each side and pairs of blue and red spots along its back. These two look-a-likes are not as harmful as the browntail moth caterpillar, though the gypsy moth is also known to cause skin irritation and damage to trees.
- Browntail moth: dark brown body, white tufts down each side, two red spots on the back, about 1.5 inches.
- Eastern Tent: white stripe down the center of the back, peacock-eye blue spots along each side.
- Gypsy moth: knobs with hairs on each side, pairs of blue and red spots along the back.
How To Minimize Exposure To Browntail Moth Caterpillars
The first line of prevention is staying away from heavily infested areas, but those are not always marked or known. It helps to wear long sleeves and pants of tightly woven fabric, which makes it harder for the barbed hairs to catch in your clothes. Tucking your pants into your socks helps too.
If you live where the browntail moth population is large, wear a mask while raking, mowing, or weed-whacking so you do not inhale hairs that get stirred up. Do your yard work on damp days, when moisture levels are high, to keep the hairs from going airborne. Wipe down or rinse off lawn furniture before you use it. And avoid drying laundry outside in spring and summer, so clothing, towels, and bedding do not pick up the hairs.
Pets and clothing can carry these barbed hairs indoors as well. Give your pets a quick brush-off before they come inside, especially after a walk in the woods or a roll in the yard in June and July. Do the same for yourself. Before heading in, swipe your clothes with duct tape or a lint roller to pick up any loose hairs. That same trick may catch ticks that have hitched a ride, so it does double duty in summer. For more seasonal know-how, see our collection of helpful household hints.
A Danger To Farms And Gardens
The browntail moth is a health concern for farms, gardens, and forests as well. The caterpillars overwinter in webs at the tops of trees. In spring, as the buds begin to open, these hungry caterpillars move in and feast on the foliage of hardwoods and shrubs, including oak, apple, crab apple, cherry, rugosa rose, hawthorn, and beach plum. They can defoliate a tree twice in a single season, which puts considerable stress on it. Feeding that heavy can stunt plant growth, lead to branch dieback, and even kill the tree.
DIY Browntail Moth Management
Prevention is the key to curtailing a widespread outbreak. The best way to clear browntail moths from your yard or garden is to watch for and remove any visible moth nests. Winter webs usually sit on the ends of tree branches, made of white silk wrapped tightly around leaves and twigs. Web clipping is advised between October and mid-April, before the caterpillars emerge from the winter webs and start feeding on new leaves. Clip any webs you can safely reach, and stay clear of hazards such as power lines. Leave the hard-to-reach ones to a professional. Once a web is removed, throw it in the trash, burn it, or soak it in soapy water for a good long while.
If you miss the window for web removal, insecticides labeled for controlling caterpillars are often effective when applied consistently before late May. Consider hiring a licensed pesticide applicator if the job is beyond a simple home treatment. If you would rather keep your beds chemical-free, a few of our old-fashioned household remedies are worth keeping on the shelf for the rest of the garden.
Browntail Moth by Region and Season
The browntail moth follows a steady yearly cycle, and knowing which stage you are in tells you what to do next. The hairs are a hazard for far longer than the caterpillars are out, so the calendar matters as much as the place.
By region, the heaviest activity stays along the coast of Maine and on Cape Cod, though pockets turn up across New England wherever the host trees grow. Because the toxin lingers in the environment for one to three years, even areas where the caterpillars have thinned out can still carry a risk on a windy day or during yard cleanup.
Browntail Moth History
You may already know this troublesome creature, especially if you live in the northeastern United States. The browntail moth, Euproctis chrysorrhoea, was accidentally introduced to Massachusetts from Europe in 1897 and spread quickly. By 1913 this public health nuisance had swept across New England and as far north as Nova Scotia, reaching south into Long Island as well. More than a century later, it remains a fixture of the Maine and Cape Cod coast, which is why the same precautions our grandparents used still hold up today.
Browntail Moth Rash: Frequently Asked Questions
How do you treat a browntail moth rash at home?
Wash your clothes and take a cool shower as soon as you can after exposure. A few hours later you may get an itchy, blistered, poison-ivy-like rash. Take Benadryl or apply hydrocortisone cream to ease the symptoms. A bar of Poison Ivy Soap helps calm the rash too. Most cases last from a few hours to several days, though sensitive skin can react for up to several weeks.
When are browntail moth caterpillars most dangerous?
The greatest risk runs from April through July, when the caterpillars are in their third larval stage. The toxic hairs do not disappear with them, though. They can stay active in the environment for one to three years and may become airborne again if disturbed.
What does a browntail moth caterpillar look like?
It has a dark brown body about 1.5 inches long, a segmented white stripe running down each side, and two noticeable red spots on the back. Younger caterpillars may not show the white stripes yet. The whole body is covered in toxic, barbed hairs, so never handle one with bare hands.
How do I tell a browntail moth caterpillar from a look-a-like?
Browntail caterpillars have white tufts running along each side. The Eastern Tent caterpillar has a white stripe down the center of its back with peacock-eye blue spots, and the gypsy moth caterpillar has knobs with hairs and pairs of blue and red spots. The look-a-likes are less harmful, but the gypsy moth can still irritate skin and damage trees.
When should I remove browntail moth webs?
Clip winter webs between October and mid-April, before the caterpillars emerge and start feeding. Remove only the webs you can safely reach, stay clear of hazards like power lines, and leave the high ones to a professional. Throw the webs in the trash, burn them, or soak them in soapy water. If you miss the window, caterpillar insecticides applied before late May are often effective.
When should I see a doctor for browntail moth exposure?
Seek medical attention right away if you have trouble breathing after exposure, which can happen if the hairs are inhaled and may lead to more serious problems. For an ordinary skin rash, home care is usually enough, but do what is best for you and your family.
Have you ever seen the browntail moth or suffered from its rash? Let us know in the comments below. And remember, our Poison Ivy Soap helps with browntail moth rash too.
Natalie LaVolpe
Natalie LaVolpe is a freelance writer and former special education teacher. She is dedicated to healthy living through body and mind. She currently resides on Long Island, New York, with her husband, children, and dog.
- Natalie LaVolpe
- Natalie LaVolpe
- Natalie LaVolpe
- Natalie LaVolpe
This is a horrible rash and the fact that there are no warnings posted in places where there are obvious infestations like Lake Pemaquid Campground in Damariscotta, Maine is just plain wrong. This causes serious health problems! I am covered in welts and will have terrible scarring. I had to throw out my camping gear because the toxic hairs are likely all over everything and I had no idea this was even possible. Had there been a public posting I could have at least tried to protect myself and my dogs or reconsidered camping there. I feel like that’s extremely irresponsible of both the business, the town and the state. That campground has a serious infestation that they know about but but say it’s “wildlife” I have tried witch hazel, aloe, rose water, teenu spray, prescription strength (2%) hydrocortisone cream, Afterbite natural, colloidal oatmeal bath (Aveeno) and ice. Plus Benadryl around the clock and Ibuprofen. Nothing is working. I want to tear my skin off. You can’t get the hairs out of your skin bc they are so tiny and barbed, and they continue to release toxin. This caterpillar is a creature straight out of hell.
I didn’t realize the rash I had was a brown tail moth. I didn’t think I came in contact with one. Well, looking today around my door my place is covered in them! I was given prednisone and hydroxizine for this mysterious rash. It didn’t help. Out of desperation to stop this insane itching that seemed to spread when i scratched it, I reached for some tinactin cream and it cleared this rash up within three days i tried the hydrocortisone creams and the calamine lotion which did nothing. I hadn’t noticed these moths around my door, I thought maybe the cat came in contact with something or i’m allergic to her fur. NOPE! Those suckers are outside my door! Time to get rid of them. So try some tinactin cream or spray and see how it works for you.
Ouch! We’re sorry you had a run in! Glad you were able to heal up quickly.
I have had a severe case of brown tail that goes over every single extremity front and back for five years. I live under a huge oak tree so there is no way for me to escape it’s wrath. After trying different remedies and having it last for me about a month and a half in duration I can tell you what really works. Calamine and baking soda are a joke. My friend taught me at the first slightest itch to immediately use rubbing alcohol or hand sanitizer on it immediately. Keep putting it on the area over and over as soon as it starts itching. Bathing in the ocean brings such an insane amount of relief too. If it’s burning and nothing works run immediately to water for immediate relief. I also have a spray nearby made of witch hazel hydrocortisone lidocaine I shake it all up in a dollar tree water bottle to spray on me as needed. Lastly my new found best friend is the extra strength icy hot with double the menthol. I put that on as needed when nothing else works. I promise you if u follow my advice you will be ok.
Vaseline and Rose Water has worked wonders, first I cleaned with rosewater then applied Vaseline no itch at all, gonna try mixing with tape idea after i clean this off.
Packing tape works wonders without chemicals. Apply to the surface with light pressure then peal away. Quick, easy, instant relief.
Have it now. Been using topical triamcinolone (steroid) and Benadryl 50mg every 12 hrs for 4 days with no relief. Only relief is from an ice pack but pain and intense itching return as soom as I remove the ice pack. Fortunately, was masked at the time of exposure, so didn’t inhale any. Rash goes right up to the borders of the mask but spares the area that was covered by the mask.
Woe is me! Both arms. Couple of things I found out: the “prescription” your doc can send the pharmacy is nothing more than Benadryl plus cortisone plus lidocaine dissolved in witch hazel and shaken up. You can make this yourself. Consult your doc to verify proportions. Keep in fridge and discard after 1 month. Apply twice a day but no more than 3 times a day due to the steroid. Also, keep the affected area cool. Don’t take hot showers or bundle up to stay warm. If it’s on your arms as mine is, wear a vest rather than a sweater. We hired a boom truck to get rid of the webs early this spring before the larvae emerged, and they still got us!
Uggh! Good luck! Hope you feel better.
Last June my forearms were covered with the rash…I’m a gardener and am always outside…I layered several creams to fight the itchiness which helped…I stocked up ahead of time for this year..I’m in Central Maine and they’re rampant, unfortunately..
Yes we have had some of our staff get this rash too. Good luck. They are very abad in Maine this year.
? Thank you for the information. ?
Hi Angela,
Glad you found it useful and thanks for leaving a comment!
Yes had it last spring 2021 it was way worse than poison ivy. Its a itchy painful rash lasted two weeks! My ace is on Troy Maine…. I hope these caterpillars drop off like the gypsy months did..
Hi John,
A few of our colleagues at Farmers’ Almanac have also experienced the rash. Will keep your fingers crossed that they find a similar ending to the gypsy moth. Thanks for leaving a comment here.