A person with chiggers has a skin infestation by a tiny insect.

Chiggers is the name used for the larvae of a very small insect, called the harvest mite. Larvae are immature forms of insects after they hatch from the egg. The mite is found on tall grasses in the southern part of the US. The larvae attach to the surface of the skin. The term, chiggers, is also used to describe the itchy, red rash caused by the harvest mite larvae.