What Are Chiggers?
- Chiggers are juvenile forms of a mite from the family Trombiculidae.
- Chiggers are only barely visible to the naked eye. Juvenile forms are red in color and have 6 legs.
- Chiggers live in all parts of the world. They are most commonly found in
- grassy fields,
- parks, gardens, and
- in moist areas around lakes or rivers.
- Symptoms of chigger bites include intense itching, and flat or raised red bumps on the skin. They sometimes have an appearance of a blister.
- Treatment for chiggers include home remedies to combat itching as well as over-the-counter (OTC) medications.
- Chigger bites can be prevented by using insect repellants, washing clothing worn outside in hot water, and avoiding areas favorable for chiggers, such as low-lying vegetation near a humid source.
The chigger mite is about 1/150th of an inch in length, meaning it is only barely visible to the naked eye. The juvenile forms, which bite humans, have six legs, while the adult forms have eight legs. Chigger mites are red in color, and the juvenile (biting) forms require a relatively humid environment, so they are most commonly located in vegetation that is near ground level. When human skin or clothing comes in contact with low-lying vegetation that hosts chiggers, the mites can infest the human and migrate on human skin in search of a feeding area.
Chiggers most commonly bite in areas of thinned skin such as wrinkles and folds. Therefore, chigger bites are commonly observed in the crotch and groin areas, in the armpits, and in the folds behind the knees. The ankles are also a common site for chigger bites. Other areas that are commonly bitten by chiggers are areas where the compression of clothing (such as belts) presents barriers to their migration.
A popular myth about chiggers is that they burrow into the skin and remain there, but this is incorrect. When the chigger bites, it inserts its feeding structures and mouth parts into the skin. They inject enzymes into the host skin that destroy the host tissue. The area then hardens, and a feeding tube, called a sylostome, develops at the bite area. Chiggers can feed on the skin for a few days through this structure if they are not disturbed.
Symptoms begin after the chigger has started to inject enzymes into the host skin. The actual bite itself is not noticeable.
- Symptoms of chigger bites include:
- Itching, that can be quite intense
- A raised or flat red bump on the skin
- A skin bump resembling a blister or pimple
Itching is the main symptom, and itching usually is most intense 1-2 days after the initial bite. The itching can last for several days, and it can take up to 2 weeks for the areas to return to normal appearance.
Any condition characterized by intense itching can lead to scratching. In turn, scratching can lead to disruption of the skin, with the potential for secondary bacterial infections of the skin.
When to Seek Medical Care for Chiggers
Chigger bites can typically be managed at home without the need for medical care. However, medical care should be sought if a person has been bitten by a chigger and develops signs of a secondary bacterial infection of the skin (spreading areas of redness, warmth, pus, and increasing tenderness or pain).
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How do you get rid of chiggers?
Treatment of chigger bites is directed toward relief of the associated itching (see medical treatment below); this will reduce the chance of secondary bacterial infections due to scratching which can break down the skin barrier to infection.
Home Remedies for Chiggers
Over-the-counter (OTC) medications can be used if necessary for control of symptoms of chigger bites. There have been many home remedies reported to treat chigger bites, but many of these are based upon the incorrect belief that the chiggers burrow into and reside in the skin. Home remedies designed to get rid of chiggers, such as bleach, nail polish, turpentine, or alcohol applied to the bites in an attempt to "suffocate" the chiggers are not effective since the mites do not actually reside within the skin.
The only effective treatments are anti-itch creams and medications (see below). Home remedies to relieve itching, such as cool showers or baths, colloidal oatmeal baths, or cool compresses may bring some relief.
Where do chiggers live?
People can take steps to prevent being bitten by chiggers using the following methods:
- Wash the skin with soap and water after outdoor activity.
- Wash clothing that has been worn outdoors with hot water.
- Avoid vegetation that is low to the ground when outdoor temperatures are favorable to chiggers. (Chiggers do not bite at colder temperatures [below 60 F or 15.5 C] and are not found in areas hotter than 99 F or 37.2 C.)
- Use insect repellents, such as DEET (carefully follow instructions on any insect repellent as some applied inappropriately may cause problems, especially in children).
- Wear long pants and long sleeves during outdoor activity along with high shoes or boots. Pant legs should be tucked into boots if possible.
Chigger bites resolve on their own without any long-term complications. However, scratching of affected areas can result in skin wounds that can become infected by bacteria. Travelers to areas in Asia should be made aware that endemic scrub typhus from chigger bites needs to be treated quickly with appropriate antibiotics as untreated infections can lead to poor outlooks (encephalitis, pneumonitis, and death).
Medically reviewed by Avrom Simon, MD; Board Certified Preventative Medicine with Subspecialty in Occupational Medicine
Cennimo, David J. "Scrub Typhus." Updated Jul 22, 2013
Missouri Department of Conservation. "Chiggers."