Chiggers, the larval stage of certain mites, are present in California. These nearly microscopic arachnids, not insects, are commonly found in warmer, humid regions of the United States. They can cause discomfort for those who encounter them in various outdoor environments. Understanding their habits helps minimize exposure and manage bites.
Chigger Presence and Identification
Chiggers thrive across California, particularly in warm, humid areas like grassy fields, brushy regions, and wooded environments. They are often encountered in the Central Valley and parts of Southern California. The parasitic larval stage, measuring 0.15 to 0.5 millimeters, is difficult to see without magnification. These six-legged larvae congregate on vegetation, often less than a foot off the ground, waiting for a host.
When a host brushes against infested vegetation, chigger larvae quickly transfer to the skin. They do not burrow; instead, they attach to the surface, often in areas where clothing is tight or skin is thin, such as ankles, waistlines, or armpits. Once attached, they inject saliva containing enzymes that digest skin cells, creating a feeding tube called a stylostome.
Through this tube, they feed on liquefied tissue. This feeding process, which can last for several days, causes intense itching and characteristic red welts. Bites typically appear as small, red bumps, sometimes resembling pimples or blisters, and are often clustered. Itching usually begins several hours after attachment and can persist for one to two weeks.
Preventing and Treating Chigger Bites
Preventing chigger bites requires precautions in areas where they are likely to be present. Wearing protective clothing, such as long-sleeved shirts and long pants, creates a barrier against these mites. Tucking pant legs into socks or boots further reduces exposed skin and prevents chiggers from crawling underneath clothing. Applying insect repellents containing DEET to exposed skin or permethrin to clothing provides effective protection. Permethrin-treated clothing should dry before wear, and DEET should not be applied to infants under two months.
Showering promptly with soap and water after outdoor activities helps remove unattached chiggers from the skin. Washing clothes worn during exposure in hot water is advisable to kill any remaining mites.
If bites occur, treatment focuses on relieving intense itching and preventing secondary infections. Over-the-counter anti-itch medications like calamine lotion or hydrocortisone cream can be applied. Cool compresses or a cool bath can also alleviate discomfort. Avoid scratching bites, as this can break the skin and lead to bacterial infections. If symptoms worsen, signs of infection appear, or itching persists, seeking medical attention is recommended.