Plant life harbors numerous small insects and other creatures. Occasionally “buggy things” get on our skin. Bees, wasps, mosquitoes, ticks, ants and spiders are easily seen. We flick them off before they sting or attach to our skin.
However, other creatures are invisible to the human eye. We feel something but can’t seem to locate anything.
High heat and humidity can magnify the irritation. Here are a few of the super-small creatures that may cause us to itch.
Tiny itches
A chigger bite may be the most common cause of a delayed invisible itch. Chiggers are not insects. They belong to same group of organisms as mites and ticks. Chiggers do not burrow into the skin or suck blood. A chigger attaches to the skin and injects juices into the bite wound. Chigger bites produce a hard, red welt that begins to itch intensely a day or two after exposure. People may not associate the itch with the fact that they were bitten while walking through grass or weeds two days before. Itching is the result of the human immune system responding to the chigger saliva.
Other small mite bites can be traced to bats or birds nesting in an attic or on a window ledge. Sometimes they come from rats or mice. When the animal dies, the mites can come indoors and bite people. These mites are smaller than fleas or lice.
There is another group of biting insects called midges (also called “no-see-ums” or biting gnats or punkies). They are most commonly found along rivers and lakeshores. Like mosquitoes, only the females attack humans and feed on blood. The biting midge uses a saw-like mouthpart to enter our skin.
These gnats are so tiny that they can squeeze through mesh screen. However, they are weak fliers, so a porch fan can prevent them from entering the screen door. Spraying screens with bug repellent also can be an effective control.
Thrips are another tiny insect that can cause an itch. They can barely be seen with the naked eye and also can enter screen doors. Their cone-shaped mouthparts are made for rasping and sucking. Most thrips feed on plants, which may include landscape plants and grasses found next to homes. They often cause distorted and discolored flowers or buds. Their feeding also can cause gray- or white-speckled areas on leaves. Thrips are serious pests on vegetables (especially onions) and flowers (roses, gladiolus, iris). They can be brought into homes on cut flowers, plant material or clothes that have been hung outdoors.
Other itches
At this time of year, we often blame all our itches on invisible insects. Some people are so convinced their itching is caused by insects, they overuse bug spray or continually clean their skin with harsh chemicals. They develop real itching from the drying soaps or detergents.
There are lots of potential causes of itching other than pests.
Many people have plant allergies that may cause them to itch. Some itching may be caused by shampoos, cosmetics or medications. Itching and skin irritation are common during pregnancy or in people with liver or kidney problems. Insulation fibers blown through air ducts also can cause itching in some people. New and old carpeting or upholstery can cause irritation.
Causes of itches can be hard to diagnose. Clear cellophane tape can be used to capture insects. The tape is then put on a white card. For a $12 charge, we can observe the sample under a microscope Consult a dermatologist once insects are ruled out.
Contact Tom Stebbins at 855-6113 or tstebbins@utk.edu.