While those people dependant on Claritin- and Zyrtek-type medications avoid pollen like the plague, others contend with air and land attacks by insects. Allergic reactions are caused by a vast array of factors, and bug bites are a prime source.

The National Jewish Medical and Research Center reported that more than 1 million Americans report allergic reactions to insect stings and about 50 die each year from those stings. Reactions to stings fall into two categories: immediate and delayed. Immediate reactions occur within four hours of the sting, and delayed reactions may occur well after that time.

Three types of immediate reactions were identified. They are:

• Normal reaction: localized pain, swelling and skin redness at the sting site for several hours.

• Large local reaction: large area of swelling around sting site. It may be accompanied by a low fever, mild nausea, malaise and fatigue. Treatment for patients without a history of sting sensitivity includes aspirin for pain and ice to reduce swelling. Treatment for those with a history involves taking a non-sedating antihistamine.

• Anaphylaxis: the most dreaded reaction. During anaphylaxis, multiple organ systems will be affected, and usually within minutes of the sting. Flushing, itching, hives, swelling, sneezing, runny nose, throat swelling, difficulty breathing, nausea, abdominal cramping, vomiting and diarrhea are all common signs and symptoms of anaphylaxis.

It is advised that people with a history of sting sensitivity wear a bracelet identifying their sensitivity to insect stings. They also should learn to administer their own epinephrine and keep it and antihistamines available at all times. They should alert 911 immediately after epinephrine and antihistamines are injected.

Delayed reactions, while usually occurring after four hours of a sting, have been known to show up a week afterwards with reports of hives, fever, malaise and joint pain. With subsequent stings, patients are at risk for anaphylaxis and may be candidates for venom immunotherapy, which consists of shots for allergies to insect venom.

Ann Mullen, a patient education expert at the National Jewish Medical and Research Center, suggested these tips for preventing insect bites and protecting against reactions to possible bites:

• Wear long pants when hiking or mowing the grass, gloves when gardening, and shoes or sandals instead of bare feet.

• Wear white or light-colored clothes. Dark clothes and flowery designs attract insects.

• Use unscented deodorant, rinse off perspiration, avoid strong perfumes, cologne, hair oil, hair spray or lotions, and keep insect repellants and insecticide available.

• Cover food and drinks outdoors and cover garbage as well.

• People with a history of reactions should wear a medical alert bracelet or necklace stating that you are allergic to insect stings, and carry an emergency pack with contents specified by your doctor.

Address: National Jewish Medical and Research Center, P.O. Box 5898, Denver, CO 80206; 1(800)-222-LUNG, www.nationaljewish.org.