Definition

Millipedes are worm-like bugs. Certain types of millipedes release a harmful substance (toxin) all over their body if they are threatened or if you handle them roughly. Unlike centipedes, millipedes do not bite or sting.

The toxin that millipedes release keeps away most predators. Some large millipede species can spray these toxins as far as 32 inches (80 centimeters). Contact with these secretions may cause allergic reactions in some people.

This article is for information only. DO NOT use it to treat or manage an actual toxin exposure. If you or someone you are with has an exposure, call your local emergency number (such as 911), or your local poison control center can be reached directly by calling the national toll-free Poison Help hotline (1-800-222-1222) from anywhere in the United States.

Poisonous Ingredient

The harmful chemicals in millipede toxin are:

• Hydrochloric acid
• Hydrogen cyanide
• Organic acids
• Phenol
• Cresols
• Benzoquinones
• Hydroquinones (in some millipedes)

Where Found

Millipede toxin contains these chemicals.

Symptoms

If the millipede toxin gets on the skin, symptoms may include:

• Staining (skin turns brown)
• Intense burning or itching
• Blisters

If the millipede toxin gets in the eyes, symptoms may include:

• Blindness (rare)
• Inflammation of the membrane lining the eyelids (conjunctivitis)
• Inflammation of the cornea (keratitis)
• Pain
• Tearing
• Spasm of the eyelids

Nausea and vomiting may occur if you come into contact with a large number of millipedes and their toxins.

Home Care

Wash the exposed area with plenty of soap and water. Do not use alcohol to wash the area. Wash eyes with plenty of water (for at least 20 minutes) if any toxin gets in them. Get medical attention right away. Tell your health care provider if any toxin got in your eyes.

Before Calling Emergency

Have this information ready:

• The person's age, weight, and condition
• The type of millipede, if known
• The time the person was exposed to the toxin

Poison Control

Your local poison control center can be reached directly by calling the national toll-free Poison Help hotline (1-800-222-1222) from anywhere in the United States. This national hotline will let you talk to experts in poisoning. They will give you further instructions.

This is a free and confidential service. All local poison control centers in the United States use this national number. You should call if you have any questions about poisoning or poison prevention. It does NOT need to be an emergency. You can call for any reason, 24 hours a day, 7 days a week.

What to Expect at the Emergency Room

If possible, bring the millipede to the emergency room for identification.

The provider will measure and monitor the person's vital signs, including temperature, pulse, breathing rate, and blood pressure. Symptoms will be treated.

Outlook (Prognosis)

Most symptoms often go away within 24 hours after exposure. A brownish discoloration of the skin may persist for months. Severe reactions are mainly seen from contact with tropical species of millipedes. The outlook may be more serious if the toxin gets in the eyes. Open blisters may become infected and require antibiotics.

References

Erickson TB, Marquez A. Arthropod envenomation and parasitism. In: Auerbach PS, Cushing TA, Harris NS, eds. Auerbach's Wilderness Medicine. 7th ed. Philadelphia, PA: Elsevier; 2017:chap 41.

Micheletti RG, James WD, Elston DM, McMahon PJ. Parasitic infestations, stings, and bites. In: Micheletti RG, James WD, Elston DM, McMahon PJ, eds. Andrews' Diseases of the Skin Clinical Atlas. 2nd ed. St Louis, MO: Elsevier; 2023:chap 20.

Seifert SA, Dart RC, White J. Envenomation, bites, and stings. In: Goldman L, Cooney KA, eds. Goldman-Cecil Medicine. 27th ed. Philadelphia, PA: Elsevier; 2024:chap 98.