Chiggers - Facts, Bites, Treatment and Prevention

Brief Synopsis: Chigger larvae pierce the skin and inject a person with a salivary secretion that contains powerful digestive enzymes.

Once a chigger has started to inject digestive enzymes into a person's skin, often within one to three hours, the person begins to experience symptoms.

Chiggers are the juvenile, or larvae, form of a type of mite belonging to the family, 'Trombiculidae', (also called berry bugs, harvest mites, red bugs or scrub-itch mites). The mites are arachnids, such as ticks or spiders, and can be found throughout the world. Chiggers live most commonly in grassy fields, forests, parks, gardens, as well as in areas that are moist, such as near rivers or lakes. The majority of chigger larvae that cause bites can be found on plants that are fairly close to the ground because they need a high-level of humidity in order to survive. Chiggers are hard to see with the naked eye due to their length; they are less than 1/150th of an inch long. Chiggers are red and are easiest to see when they are present in clusters on a person's skin. Juvenile chiggers have six legs, while the adults have eight.

Chigger larvae attack everyone from picnickers and campers to bird watchers and berry pickers. They are found in the largest numbers in early summer when weeds, grass, and other forms of vegetation are at their heaviest. Chiggers do not burrow in a person's skin; instead, they insert their mouthparts into a person's skin pore or hair follicle. The bites create small, red-colored welts on the person's skin that are accompanied by an intense itching similar that that experienced with poison sumac or poison ivy. The symptoms of a chigger bite are many times the only way of learning that an outdoor area is infested with the creatures because they are so small. Chiggers also bite a number of animals such as turtles, snakes, birds, and smaller mammals.

Adult chiggers spend the winter either near, or slightly below, the surface of the ground or other protected places. Female chiggers become active in the Spring time, laying up to fifteen eggs each day in vegetation when soil temperatures reach sixty degrees or more. The eggs hatch into six-legged larvae capable of biting human beings. Once they have hatched, chigger larvae climb onto vegetation and seek a host to bite. Once they have fed, the larvae drop off of their host and transform into eight-legged nymphs which then develop into adult chiggers. Both nymphs and adults eat the eggs of isopods, springtails, and mosquitoes. The life cycle of chiggers is approximately fifty to seventy days, with adult female chiggers living up to a year and producing offspring for the duration of their lives. Multiple generations of chiggers are hatched in climates that are warmer, although only two or three develop each season in more northern states. Chiggers are commonly encountered in the late spring and summer.

Chigger bite

The larvae of chiggers do not burrow into a person's skin; they also do not suck a person's blood. Chigger larvae pierce a person's skin and inject the person with a salivary secretion that contains powerful digestive enzymes. The enzymes break down skin cells that the larvae ingests; the tissues become liquefied and the larvae sucks the tissues up. The digestive fluid also causes surrounding tissues to harden and form a straw-like tube of hardened flesh called a, 'stylostome,' which the larvae uses to suck further digested skin cells through.

The larvae feeds for four days, and once it has fully-fed, it drops from its host, leaving a red welt with a hard, white center on the skin that itches severely and has the potential to develop dermatitis. Swelling, itching, welts, or fever can continue for a week or longer. Scratching a bite, or

breaking the skin, can result in a secondary infection. Fortunately, chiggers are not known to spread any forms of disease in America. The majority of chigger bites occur around a person's ankles, groin, crotch area, in a person's arm pits, or behind the person's knees. Barriers to migration on a person's skin, such as belts, might be one reason why chigger bites are also common around a person's waist, or in other areas of a person's body where migration is prevented due to compression from clothing.

The bite from a chigger itself is something that is not noticeable. Once a chigger has started to inject digestive enzymes into a person's skin, often within one to three hours, the person begins to experience symptoms.

The symptoms of a chigger bite can include the following:

  • Pronounced itching
  • The itching persists for several days
  • The itch is due to the presence of the stylostome
  • The area of the bite may be reddened, flat, or raised
  • The itch is usually most intense within 1-2 days after the bite
  • Complete resolution of the skin lesions can take up to two weeks

Treating Chigger Bites

Many of the home remedies for chigger bites are based upon the belief that chiggers somehow burrow into and remain in a person's skin; these beliefs are incorrect. People have applied alcohol, nail polish, and bleach to bites in attempts to somehow suffocate or kill chiggers. Due to the fact that chiggers are not present in the person's skin, these remedies are not effective in the slightest.

Treatment for chigger bites is directed towards relieving the itching and inflammation the person is experiencing. Corticosteroid creams and calamine lotion can be used to control the itching. Oral antihistamines such as diphenhydramine can also be used to provide relief.

When a person returns from a chigger-infested area they should wash their clothing in hot, soapy water for around a half an hour. The infested clothing should not be worn again until they are washed appropriately or exposed to hot sunshine. Clothes that have not been washed, or clothes that have been washed in cold water, will still contain chiggers and reinfest a person's skin. It is important for the person to take a hot bath or shower and wash with soap repeatedly. The chiggers might be dislodged from the person's skin, but the person will still have the stylostomes that cause the severe itching.

Deep scratching with the intention of removing stylostomes may cause a person to contract a secondary infection. To temporarily relieve itching, apply benzocaine, calamine lotion, or hydrocortisone cream. Some people use cold cream, vaseline, or baby oil. Chigger bites do not cause any long-term complications of themselves. Prolonged itching and scratching can lead to skin wounds that have the potential to become infected.

Preventing Chiggers

To help prevent the presence of chiggers, mow weeds, briars, lawns, thick vegetation, and eliminate moisture and shade. Doing so will reduce the populations of chiggers. Allow sunlight and air to circulate freely. Chigger larvae have the ability to penetrate a number of types of clothing, but high boots and trousers made of tightly-woven fabric that is tucked into stocking or boots can help in deterring them. Before you enter an area where you know chiggers are present, protect yourself by using a repellent such as deet, Off, Detamide, Repel, or another form of insecticide. Apply the repellent to your skin and your clothing, particularly your arms, hands, and legs – as well as opening in your clothing. Keep moving since the worst chigger infestations happen when you are sitting or laying down.

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