By Lee Cataluna
Advertiser Columnist

A friend was having an allergy skin test done recently — the one where they write numbers on your skin and then poke you with essence of stuff like cat, dog, grass, and pollen to see what makes you itch — except along with the usual cat, dog, grass, pollen stuff, she noticed that one of the vials of allergens was labeled "Worldwide House Dust" and one said "Hawaiian House Dust."

Hawaiian house dust? Oh, the mind races with possibilities: Microscopic pieces of old rice that got stuck in the carpet; flecks of dried poi that became airborne; a layer of mango flower pollen from the nearby tree; a touch of motor oil that wafted in from the VW up on blocks across the street; not to mention the gifts geckos leave behind.

Turns out the difference between "Worldwide House Dust" and the local kind, at least as far as allergists are concerned, is much more specific: mites.

"It's not the inorganic dust particle that people are allergic to, it's the live mite in the dust that's the main allergen," explains Dr. James Sweet of the Asthma, Allergy and Sinus Center of Hawai'i.

"There was a paper written by Gary Carpenter awhile ago when he was an allergist at Tripler, and he found that there's two major dust mites, D. Pternoyssinus and D. Farinae. In Hawai'i, 80 percent of one type, D. Pternoyssinus, is more prevalent. On the Mainland, it's more 50-50 in distribution between the two mites," says Sweet.

Though some allergists test for reaction to both types of mites, others disagree. Dr. Phillip Kuo says, "It doesn't make much of a difference. Even though they're different mites, the antigen is the same, so the treatment is the same."

"In the old days before we knew about dust mites," says Dr. Victoria Wang, "allergy labs from the Mainland would come to Hawai'i and gather people's dust and label that Hawaiian House Dust."

The more you find out about dust mites, local or otherwise, the less likely you are to worry about, say, mold.

"Dust mites, they lay like 25-50 eggs every two to three weeks. There's thousands of these growing on your pillow and mattress. They're microscopic and they eat your dead skin. And so you shed your skin in your bed and that goes into the mattress and pillow and that's their food. So you just sleep in your allergen all night," says Sweet, with a decidedly Glen Grant tone in his voice.

In Hawai'i, house mites are the most common allergen. Hawai'i's high humidity and warm temperatures are conducive to mite growth. Places like Denver and Phoenix and Las Vegas aren't nearly as mite-y.

The answer? Well, there's medicines or allergy shots or, hate to say it, Martha Stewart.

"They do encasement covers," says Sweet. "We tell people to put a plastic cover around the pillow and mattress."

Or there's Vegas.

Lee Cataluna's column runs Tuesdays, Fridays and Sundays. Reach her at 535-8172 or lcataluna@honoluluadvertiser.com.