Some of the larger centipedes can inflict a painful bite, causing swelling and redness. Symptoms rarely persist for more than 48 hours.
Millipedes do not bite but may secrete a toxin that is irritating, causing burning and itching of the skin and, particularly when accidentally rubbed into the eye, causing redness, swelling, and pain of the conjunctiva or the cornea.
An ice cube wrapped in plastic and a thin cloth and placed on a centipede bite usually relieves the pain.
Toxic secretions of millipedes should be washed from the skin with large amounts of soap and water. If a skin reaction develops, a corticosteroid cream should be applied.
Eye injuries should be flushed with water (irrigated) immediately.