I woke up covered in a painful rash. A caterpillar with toxic hairs was to blame.

The moth is native to Europe and Asia and was introduced to New England in the 1800s. Maine, where I live, has a large population that comes out from hibernation in April and can cause rashes in humans until July.

The browntail moth caterpillar lives in trees

I first heard about browntail moths from my kids’ preschool. They have backwoods where kids explore nature throughout the year, and it’s not uncommon to get an email from the administration warning that some kids are coming home with rashes.

Still, the rashes I had seen on my kids were minor — little bumps on their fingers or the back of their hands. Nothing like mine, which spread on my arms, chest, back, legs, and toes.

The caterpillars’ hairs contain a toxin that, when brushed against skin, produces a poison ivy-like rash that is incredibly itchy and uncomfortable.

Derek V. Chan, a board-certified medical and cosmetic dermatologist at All Dermis Dermatology in New York City, said it’s key not to scratch the initial bumps. “You can spread the toxin and hairs to other areas of the body and cause new lesions to develop elsewhere,” Chan told me.

I tried over-the-counter products, but nothing worked

Before my dermatologist prescribed a topical steroid medication, I tried over-the-counter products to help with the itching.

I took Benadryl before bed and Claritin during the day. The ointment and gel helped ease the itchiness, but only for a little bit. I was especially uncomfortable at night and would wake up scratching my skin raw.

Now, I’m trying steroid cream, but my dermatologist warned me that I wouldn’t see results immediately. The duration of the reaction depends on your sensitivity to the toxin. In some people, it can last several weeks, Chan told me.

Chan said that on top of over-the-counter medication, “a cool bath with baking soda and/or finely ground colloidal oat powder” can ease the discomfort.

If you’ve already picked at the bumps — like I did, because I couldn’t stop scratching — Chan recommends wearing sun-protective clothing to avoid the areas getting darker from hyperpigmentation and always wearing SPF when outside.

Chan added that if your tongue swells or you have difficulty breathing after coming in contact with the toxins, it becomes a 911 emergency.

I didn’t touch an actual caterpillar

What’s tricky about browntail moth is that you don’t necessarily need to come in contact with it to get the rash. Touching an item that the moth walked over is enough to generate a reaction.

I still don’t know where I came in contact with one since my husband and three kids were thankfully spared from this torture. The only thing I can think of is that I took a nap with our dogs while my husband was doing bedtime with the kids. I assume they rolled on a caterpillar or a nest and then laid on me, transferring the toxins.

My dermatologist said she’s been seeing an increasing number of patients with browntail moth rashes. If you’re traveling to Maine this summer or your kids attend summer camp here, watch out for these caterpillars. The Maine Department of Agriculture Conservation and Forestry recommends using pesticides to control the population outdoors and a wet vac to remove any caterpillars from indoors.

Chan added that after spending time outdoors, people living in browntail moth-prone areas should keep their skin covered, take a cool shower once they are inside, wash clothes immediately after, and if they come in contact with any other surface where hairs or toxins may linger, wash bedding and towels.