Entries from January 2008 ↓

There is a helpful information sheet on mites, entitled “Biting Mites in Homes,” from the Alameda County Vector Control Services District (Alameda, California). The sheet distinguishes between rat mites, northern fowl, and tropical fowl mites:

Several types of mites are associated with cases of skin dermatitis in humans. The tropical rat
mite, Ornithonyssus bacoti, is one of the most commonly encountered species. The tropical fowl mite,
Ornithonyssus bursa, and northern fowl mite, Ornithonyssus sylviarum, both associated with domestic
or wild birds, can also be found in homes. The tropical rat mite is a parasite of rats and inhabit the area
in and around the rat’s nesting area. Although none of these species are truly parasitic on humans or
pets, they will readily bite humans. Some people are unaffected by the bites while others will
experience itching and dermatitis. The bite is normally pimple sized that itches for up to a week or so.
The bite mark may last as long as three weeks. The bites can be randomly found on the body but often
are found under areas where clothes constrict the body or areas such as under armpits and breasts.
Scratching may lead to secondary bacterial infections. Fortunately rat mites do not vector disease.
Rat mites are very small, approximately the size of a period.

The sheet includes photos of spiny rat mites and tropical rat mites, and of bites on a woman from a tropical rat mite. (Though these are in black and white, they are nevertheless helpful.)

You can click here to download a PDF and read the rest.

Oregon State provides an overview in “Mites that Bite” to various biting (and other) mites and ticks here (click to load PDF).

Texas A&M Cooperative Extension notes that the most important thing to do when faced with biting mites is to seek possible bird or rodent sources. Identifying the mite that’s biting you is crucial.

Identification and detection are not simple, since mites are so small.  You really need a professional to detect, identify and get rid of mites found in the home.

This isn’t really about what’s biting you, but a new theory suggests biting mites may have led to the extinction of dinosaurs.

CORVALLIS, Ore., Jan. 3 (UPI) — A U.S. zoologist says dinosaurs may have been killed off by tiny, biting, disease-carrying insects.

If true, it represents one of many causes, not the sole reason for extinction.

The concept is outlined in the new book What bugged the dinosaurs? Insects, Disease and Death in the Cretaceous by George and Roberta Poinar.

“We don’t suggest that the appearance of biting insects and the spread of disease are the only things that relate to dinosaur extinction,” Poinar said. “Other geologic and catastrophic events certainly played a role. But by themselves, such events do not explain a process that in reality took a very, very long time, perhaps millions of years. Insects and diseases do provide that explanation.”

You can click here to read the rest of the story from United Press International.

Scabies occurs when the Sarcoptes scabiei mite burrows under your skin.

This photo shows someone with scabies on her hand, after six days’ development:

According to the CDC’s page on scabies, the symptoms are:

• Pimple-like irritations, burrows or rash of the skin, especially the webbing between the fingers; the skin folds on the wrist, elbow, or knee; the penis, the breast, or shoulder blades.
• Intense itching, especially at night and over most of the body.
• Sores on the body caused by scratching. These sores can sometimes become infected with bacteria.

Scabies can take 4-6 weeks to appear after exposure. You can catch scabies by prolonged skin-to-skin contact with others, or by sharing items that touch the skin, like towels, unwashed clothing, and sheets. (The CDC website says it is not commonly caught via a handshake or a hug.)

If you think you have scabies, do not try to treat it on your own. See a doctor.

Sometimes other conditions (like bed bug bites) can be mistaken for scabies, even by a doctor.

It’s a good idea to ask your doctor to confirm the presence of scabies, by doing a skin scraping. But remember, even a negative result from the scraping does not mean you do not have scabies.

If you do have scabies, you need to be treated with a prescription medication. One treatment usually works, but if not, the doctor will want you to repeat it or try another lotion. In order to make sure you don’t get it again from your clothing and sheets, you will also need to wash and dry all worn clothing and bedding on hot.

Photos of scabies on skin from the University of Iowa Hardin MD site.

Here’s a page on scabies (La sarna) in Spanish.

Scabies mites look like the following picture, but of course, you won’t be able to see them.

Scabies, by MacAllen Brothers (Micah MacAllen). Used under a Creative Commons Attibution/Share-Alike license.