Brown-Tail Moth Rash: Symptoms, Duration and Treatment

May 18, 2024 | 2 min read

Question on this topic? Get an instant answer from AI Doctor.Instant answer from AI Doctor.

Brown-tail moth rash is caused by contact with the toxic hairs of the brown-tail moth caterpillar, resulting in red, itchy bumps. Symptoms include intense itching and swelling, lasting from a few days to two weeks; treatment involves washing the area, using cool compresses, and avoiding scratching.

What is Brown-Tail Moth Rash?

Brown-tail moth rash is a skin condition caused by contact with the toxic hairs of the brown-tail moth caterpillar. The rash typically develops when these tiny, barbed hairs embed into the skin, leading to an allergic reaction, according to the NPS.

This reaction results in red, itchy bumps that can form clusters and spread across the affected area. The rash is common in areas exposed to the caterpillar's hairs, such as the arms, neck, and face.

The severity of the rash can vary, with some individuals experiencing mild irritation and others suffering from intense itching and inflammation.


  • Contact with caterpillar hairs: The primary cause is direct contact with the brown tail moth caterpillar's toxic hairs.
  • Airborne hairs: The hairs can become airborne and cause a rash when they land on the skin.
  • Contaminated clothing or surfaces: Touching clothing, bedding, or surfaces contaminated with the caterpillar's hairs can also lead to the rash.
  • Seasonal activity: The risk of developing the rash is higher during late spring and summer when the caterpillars are most active.

What Does Brown-Tail Moth Rash Look Like?

Brown tail moth rash looks like small, red bumps on the skin. These bumps may form clusters and spread.

The rash is often itchy and can become inflamed. It may also develop into a blistering condition if scratched.

Look for raised, red bumps that are itchy and in clusters. The rash typically appears on exposed skin areas.

Symptoms of Brown-Tail Moth Rash

Initial symptoms

  • Tingling or burning sensation on the skin
  • Red bumps appearing shortly after contact

As the rash progresses, the itching can become more intense. The rash area may also swell and become more irritated. The rash can cause significant itching and discomfort. Scratching may lead to further irritation and potential skin infections.

How Long Does Brown-Tail Moth Rash Last?

The duration of a brown tail moth rash can vary depending on the severity of the reaction and the individual's skin sensitivity. Typically, the rash lasts for a few days to a couple of weeks. In most cases, the intense itching and redness subside within a week.

However, if the rash is severe or if there has been extensive contact with the caterpillar hairs, the symptoms might persist for up to two weeks. Proper care and avoiding further exposure to the hairs can help shorten the duration of the rash.

How to Treat Brown-Tail Moth Rash?

Treating brown tail moth rash involves a combination of relieving symptoms and preventing further irritation. Here are some steps to manage the rash:

  • Clean the affected area: Gently wash the skin with soap and water to remove any remaining caterpillar hairs.
  • Avoid scratching: Scratching can worsen the rash and lead to infections. Keep nails short to minimize damage.
  • Cool compresses: Applying cool, wet compresses can help reduce itching and swelling.
  • Moisturize: Use gentle moisturizers to soothe dry and irritated skin.
  • Avoid further exposure: Stay away from areas where brown-tail moth caterpillars are present, and wear protective clothing when necessary.
  • Consult a healthcare professional: If the rash is severe or persists, seek medical advice for additional treatment options.
AI Assistant

Have Questions?

Have a question on this topic? Submit it here and get an instant answer from our AI Doctor.

Privacy Note!This tool is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always consult a professional before taking any actions.

Consult Top Doctors

Consult Top doctors from the US & Europe to validate your diagnosis and treatment strategy before making crucial health decisions.


Top doctors





You’re only one click away from a life-changing journey

Virtual health assistant powered by AI
350+ world-renowned Doctors