Chiggers are tiny mites, not insects, that can cause an intensely itchy reaction when their larval stage bites humans. These almost invisible arachnids, related to spiders and ticks, are generally harmless in North America, but their bites can be quite bothersome. While the irritation they cause is significant, chigger bites do not typically lead to serious health issues. Managing the itch and preventing future encounters can alleviate the discomfort from these common outdoor nuisances.
Soothing the Itch
Immediate action after potential exposure minimizes the impact. Taking a warm, soapy shower and scrubbing the skin with a washcloth helps dislodge any attached chiggers. Thoroughly washing clothes worn during exposure in hot water also helps remove any lingering mites.
Over-the-counter options provide relief from intense itching. Topical anti-itch creams or ointments with hydrocortisone, calamine lotion, camphor, menthol, or pramoxine soothe skin and reduce inflammation. Oral antihistamines also alleviate severe itching or sleep disruption. Applying a cold compress or ice pack numbs skin and decreases swelling, offering temporary comfort.
Home remedies can also manage discomfort. A cool bath, perhaps with colloidal oatmeal, soothes irritated skin. A baking soda and water paste, applied directly to bites, may reduce itching and inflammation. Avoiding scratching is important to prevent breaking the skin, which could lead to secondary bacterial infections.
What Happens When a Chigger Bites
Chiggers are the larval stage of mites and the only stage that feeds on humans. These tiny, six-legged larvae, measuring about 0.15 to 0.3 millimeters, are nearly invisible. When a chigger larva bites, it does not burrow into the skin or suck blood—a common misconception. Instead, it pierces the skin with its mouthparts and injects saliva containing digestive enzymes.
These enzymes break down skin cells, which the chigger ingests for nourishment. The injected saliva hardens surrounding tissue, forming a straw-like feeding tube called a stylostome. Intense itching and red bumps from chigger bites are primarily an allergic reaction to this saliva and the stylostome. Chiggers typically feed for a few days before detaching, but the allergic reaction and itching can persist for days, sometimes up to two weeks, even after the chigger is gone. Bites often appear as red spots or pimples, sometimes in lines, commonly found where clothing fits tightly, such as around ankles, waistbands, or behind the knees.
Avoiding Chigger Bites
Preventing chigger bites involves minimizing exposure and creating barriers. Avoid areas where chiggers are common, such as tall grass, overgrown fields, wooded areas, and moist, grassy spots, especially during late spring, summer, and early fall when they are most active. If entering these environments, protective clothing significantly reduces bite risk.
Long-sleeved shirts, long pants, and tall socks (with pant legs tucked into socks or boots) create a physical barrier against mites. Treating clothing with permethrin, an insecticide that kills chiggers on contact, adds protection. For exposed skin, insect repellents with DEET or picaridin deter chiggers. Apply these repellents to exposed skin, especially where clothing might not fully cover. After outdoor time, showering with soap and water as soon as possible washes away any chiggers before they begin to feed.