FAQs about house dust mite and storage mite allergies
By bringing pets into our homes, we’ve increased their exposure to these common skin irritants.
Where are storage mites commonly found?
These particular mites (Tyrophagus putrescentiae, Lepidoglyphus destructor, Acarus siro) are present in dry foods, cereals, grains, straw and cheese—i.e., substances that can get moldy. Like dust mites, storage mites can cause nonseasonal signs, including pruritus, erythema and recurrent otitis in dogs and cats. They're well-known in humans for causing asthma and allergic rhinitis ("baker's lung").
Data have shown that storage mites live in conjunction with house dust mites and can be found in bedding, mattresses, upholstered furniture and fabrics. One study in humans found storage mites to have overtaken dust mites as a leading source of allergy.
A popular misconception is that storage mites are present in bags of food or cereals from the manufacturer. In one study, out of 10 bags of dry dog food, one was found to have storage mites, but the rest developed the mites after being in the owners' homes.2
What's the best way to prevent storage mite occupation of dry pet foods?
Advise clients who have allergic animals to buy dry pet food in small bags, immediately empty the bags into sealed bags and place them in a freezer. Keep one bag out in an airtight container and feed the pet from that bag first. Take the food that is next to be fed to the animal out of the freezer and place it in an air-tight container to thaw.
Canned food or a cooked diet that doesn't contain grains or cereals may be fed to the animal. For example, cooked hamburger is OK but not the bun; cooked oatmeal instead of Cheerios; cottage cheese instead of sliced cheese (since it doesn't mold as easily).
Keep in mind that it's unknown if microwaving or freezing dry food is sufficient enough to kill storage mites. The reason for freezing unused new food is to prevent the food from being contaminated with storage mites in our homes.
How is an allergy to storage mites diagnosed?
This allergy should be suspected if the problem is nonseasonal, especially with facial involvement (e.g., pruritus, recurrent otitis, asthma or waxy otitis). A cooked diet with no cereals, grains or cheese can be given for four to six weeks to see if the patient improves.
Perform skin or serum testing for various storage mites, but advise the client that mites cross-react on skin testing, and some animals may test positive for both dust mites and storage mites. Some of these patients will be allergic to both, while others will be allergic only to one type of mite, and a false positive reaction may occur to the other mite.
What about treatment?
Immunotherapy, either sublingual or subcutaneous, may be used if the owner doesn't want to feed a nondry diet.
Unfortunately, it takes only a tiny amount of mite allergen to elicit an allergic reaction in our pets. Hopefully, with more knowledge of these mites and ways to eradicate them, we can make our allergic pets more comfortable.
Dr. Alice Jeromin is a pharmacist and veterinary dermatologist in private practice in Cleveland, Ohio. She is a graduate of The Ohio State University College of Veterinary Medicine and an adjunct professor at Case Western Reserve University's College of Medicine in Cleveland.
1. Colloff MJ. Dust mites. Collingwood, Australia: CSIRO; 2009.
2. Brazis P, Serra M, Sellés A, et al. Evaluation of storage mite contamination of commercial dry dog food. Vet Dermatol 2008;19(4):209-214.
1. Reedy LM, Miller WH Jr, Willemse T. Aeroallergens and aerobiology. Allergic skin diseases of dogs and cats. 2nd ed. Philadelphia, Pa: WB Saunders l997;59-61.
2. Bensignor E, Carlotti DN. Sensitivity patterns to house dust mites and forage mites in atopic dogs: 150 cases. Vet Dermatol 2002 Feb;13(1):37-42.