Mites May Lurk in Pantry

April 5, 2004

Heather Heilman
Phone: (504) 865-5714

Jane El-Dahr induced curiosity in grocery shoppers and distress in store managers last year when she pulled every box of beignet mix off the shelves of supermarkets all across town. She wanted to find as many different lots of the mix as possible.

beignets"I'm sorry to say that many of the grocery stores had expired boxes on the shelf," said El-Dahr.

She isn't a mystery shopper gone mad, but a professor of pediatrics who specializes in allergies and immunology. A few years ago, she had a young patient who suddenly went into anaphylactic shock, lost consciousness and nearly died.

Doctors were stumped about what might have caused such a severe reaction until they learned the child had just eaten beignets his mother had made at home.

Immediately afterward he started itching and feeling short of breath. Skin tests showed no allergies to weeds or any of the listed ingredients in the beignet mix, but an extreme allergic reaction to house dust mites, microscopic critters in the arachnid family (as are spiders and tics).

Some of the beignet mix was still in the box. El-Dahr took it back to her lab, where she found that it was heavily contaminated with house dust mites.

"At the time there was one other report in the literature about a tourist who had visited New Orleans and bought a box of beignet mix, gone home and made beignets and had a severe reaction. Since then, several other cases have been reported," said El-Dahr.

Dust mite allergies are fairly common and the unfortunate fact is that mites thrive in New Orleans' hot, humid environment. Flour is the favorite habitat of dust mites. Even a few mites in a particular flour source can become a big problem in the right environment. Although the heat of cooking kills the mites, it doesn't break down the protein in their bodies that provokes an allergic reaction.

El-Dahr bought 20 boxes of beignet mix from stores throughout the New Orleans area. Some were expired and some were not. She and medical resident Dan Demerell opened all the boxes at the same time and tested them for mites. They found that all of the expired boxes were contaminated, as were a few of the unexpired ones.
"We had the idea that the boxes became contaminated in the home when they were opened and left to sit in the cupboard. But in fact they came from the store already contaminated," she said.

She and Demerell have asked people to bring in pancake mix, cornmeal and other flour products that have been opened and sitting in the kitchen. So far they haven't found anything else that has been contaminated.

"The question we have is how widespread is this? It's not uncommon for people to have an episode that seems to be an allergic reaction to something, but they never find the source."

Consumers in New Orleans and other steamy locales can protect themselves by checking expiration dates before buying flour products. Don't buy items that have expired or are near the expiration date. At home, it's best to store such products in airtight containers, preferably in the refrigerator.

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Tulane University, New Orleans, LA 70118 504-865-5000