Chiggers are tiny, biting mites that can turn an enjoyable outdoor experience into an intensely itchy ordeal. These microscopic creatures are a common concern for people spending time in grassy or wooded areas. Understanding what chiggers are and how to manage their bites is important for anyone who enjoys the outdoors.
Chiggers in Oregon
Chiggers are found globally, thriving in warm, humid environments. While often associated with the southeastern and midwestern U.S., they are present in Oregon, particularly in dense vegetation like tall grasses, wooded areas, and near water. They are most active from late spring through early fall, when ground temperatures are between 77 and 86 degrees Fahrenheit. Activity decreases below 60 degrees Fahrenheit and stops below 42 degrees Fahrenheit.
Their distribution in Oregon tends to be spotty, meaning they might be heavily concentrated in one specific area while being absent nearby. Chiggers often stay clumped together on leaves and grass, usually less than a foot off the ground. They wait for a host to brush by before attaching themselves.
Understanding Chiggers
Chiggers are the larval stage of certain mites, belonging to the same family as spiders and ticks. These tiny, six-legged larvae are nearly invisible to the naked eye, measuring only about 0.15 to 0.3 millimeters in length. They attach to a host, including humans, using tiny claws and then pierce the skin.
Contrary to misconception, chiggers do not burrow into skin or feed on blood. They inject digestive enzymes that liquefy skin cells, which they then consume, creating a hardened feeding tube. The intense itching and red welts are a reaction to these enzymes and the body’s immune response. Bites appear as itchy red bumps, sometimes with a blister or hive-like rash, often in clusters where clothing fits tightly, such as ankles, waist, or behind the knees. Itching usually begins hours after exposure and can last for several days, up to two weeks.
Avoiding and Treating Chigger Bites
Preventing chigger bites involves minimizing exposure to infested areas and using protective measures. When venturing into grassy or wooded environments, wearing long-sleeved shirts and long pants tucked into socks or boots can help. Loose-fitting, tightly woven fabrics offer better protection by making it harder for chiggers to reach the skin. Avoiding direct contact with tall grass, weeds, and dense brush is also advisable.
Using insect repellents can provide additional protection. Products containing DEET can be applied to exposed skin and clothing openings. Permethrin, an insecticide, can be applied to clothing and gear, but not directly to skin, providing long-lasting protection even through several washes. Upon returning indoors, taking a warm, soapy shower and thoroughly scrubbing the skin can dislodge any chiggers that may have attached. Washing exposed clothing in hot water also helps eliminate any lingering mites.
Treating chigger bites focuses on alleviating itching and discomfort. Over-the-counter anti-itch creams (e.g., calamine lotion, hydrocortisone, menthol, or pramoxine) and oral antihistamines (e.g., diphenhydramine) can provide relief and reduce inflammation. Applying a cold compress may also soothe the skin. Avoid excessive scratching to prevent skin breakage and secondary bacterial infections. Seek medical attention if symptoms worsen, show signs of infection, or do not improve within two weeks.