Although both centipedes and millipedes have segmented bodies, millipedes have two sets of legs per segment directly under their body, whereas centipedes have only one set of legs per segment positioned on the side of their body. Seen from the side, centipede bodies appear more flat and millipedes appear more rounded.
Some 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, particularly when accidentally rubbed into the eye.
Image courtesy of the Public Health Image Library of the Centers for Disease Control and Prevention.
DK IMAGES/SCIENCE PHOTO LIBRARY
An ice cube wrapped in a 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 irrigated immediately.
Tetanus prophylaxis should be given (see table Tetanus Prophylaxis in Routine Wound Management).