Browntail moth caterpillar rash
Browntail moth caterpillar rash

My friend Jackie decided to sit under some oak trees one summer without noticing all of the browntail moth caterpillars above. She paid a dear price. Here’s what she posted to her friends on Facebook:

“Browntail moth rash is REAL! Real painful, real itchy, real gross and all over my upper arm/pit/and back and I was wearing a long-sleeved shirt and the browntail moth [caterpillar] hairs went right through the fabric.”

I got the remedy

Jackie said Cortisone 10 cream helped, but not a lot, and she had to work hard not to scratch. Several people responded with sympathy and remedies she might try. 

I also shared her story on Facebook and many people were quick with advice:

  • Whoa! Maybe a baking soda poultice?
  • We used a paste of baking soda and witch hazel and just leave it on the affected area for 5-10 minutes, 3X/day.
  • Is nasty stuff. got on neck and shoulders, had one on my arm and washed with Dawn and water, really seems to help.
  • Sounds weird but, try Banixx wound cream. You get it from a horse or dog’s supply. It helps things heal much faster.
  • Coastal Pharmacy and Wellness makes a spray that I have heard really helps the itching. 
  • You can also make a compound at home of Benadryl cream, hydrocortisone cream, aloe and witch hazel. I made a batch every night and used a cotton ball to apply to all the areas affected. I applied several times a day for the severe itching. It’s awful to be exposed to these caterpillars. You don’t know you have been infected with the hairs till the severe rash appears.
  • If this is a generalized allergic reaction (hives rather than a rash), she may need to see a doctor for treatment. And if at any time her tongue swells or she begins to wheeze, it becomes an emergency. I had a patient once who got body-wide hives from a caterpillar bite, and he needed emergency treatment for the allergic reaction he had.
  • How about Benedryl for rash?
    • Another person responded: yes it is good for itching, but don’t use both the spray and the pills. One or the other.
  • I have a terrible reaction to browntail. I would recommend Sarna which is a lotion you can get at the drugstore, or the prescription Browntail spray remedy that Kennebec Pharmacy compounds. She needs to soothe it, and not scratch or rub it. She might even have to bandage it lightly to keep her hands off it. Increasing the skin irritation by rubbing leads to infection. Also maybe an oral antihistamine will help?
  • This works for me! I had tiny rashes though:
    • I learned how to make an effective treatment from a pharmacist at Walgreen’s. You need a small Tupperware dish, cotton balls, a bottle of Witch Hazel, a tube of hydrocortisone cream, and Benadryl cream. You squeeze out half of the tubes for both creams and then add witch hazel until you have the consistency of calamine lotion. Then apply to the area with a cotton ball. You can use this four times a day.  
Courtesy Maine Center for Disease Control & Prevention

Feeling better

Jackie eventually recovered, but I heard a lot more caterpillar tales of woe, and have already begun to hear some over the past couple of days. The caterpillars are active from April to June, so be on the lookout. The hairs are still toxic throughout the summer, but according to the Maine CDC,  they get washed into the soil and are less of a problem over time.

Browntail moth caterpillars in 2022

If you want to know what’s happening or expected to happen this year, I found quite a bit of information on the Maine Forest Service Website. (I don’t know — between caterpillars and ticks, sometimes I think we’re just plain outnumbered!)

Knock out browntail campaign