Monday, August 14, 2006
Sting is nothing to sneeze at if allergic
By Dr. Yong Tsai
The Daytona Beach News-Journal
Up to 5 percent of people in the United States are affected by stinging (and biting) insect allergies. In Florida, the majority of the problem insects are bees, wasps, yellow jackets, hornets and the unforgettable fire ant — all of which can pack a big punch.
Typically, wasps build honeycomb nests under eaves and rafters, while hornets construct larger papier-mache nests that hang in trees and shrubs. Yellow jackets build their hives in the ground, under logs or in walls. And, as we Floridians are well aware, we must watch our step outside to avoid fire ants.
What determines whether someone might require immunotherapy for a particular insect-venom allergy depends on the intensity of his or her reaction.
A typical local reaction after an insect sting is mild redness, warmth, swelling and pain at the sting site. The pain is most often transient and disappears on its own within several hours.
Sometimes, people may experience a more extensive local reaction, with swelling extending from the sting site to cover a large area.
The most dangerous allergic reaction is known as a generalized reaction (anaphylaxis) that can produce shortness of breath, wheezing, dispersed hives, airway swelling, increased heart rate, loss of consciousness and even death.
These life-threatening allergic reactions usually occur within 15 minutes of the sting, rapidly progress and require immediate medical treatment with epinephrine, antihistamines and even corticosteroids.
At times, toxic reaction, not an allergic reaction, may follow as a result of multiple stings. Because insect venom contains many potent pharmacological agents, vascular collapse, hypotension, shock and even death may occur.
If you have a history of generalized allergic reaction to an insect sting, your chances are 60 percent or better of a similar or more serious reaction if you are stung again.
In these cases, skin testing should be performed to confirm the allergy. Then, venom immunotherapy, (injections of the offending venom to stimulate the immune system and to reduce the severity of future reactions) should be initiated.
The process is usually completed in three to five years, and venom immunotherapy has proven to be 97 percent successful in preventing future allergic reactions.
Even after patients undergo immunotherapy, it is advised to carry the self-injectable epinephrine (Epi-Pen), because not all patients will maintain a lifelong immunity to insect venom.
A word to the wise: If an insect has stung you, immediately scrape the stinger out with a blunt-edged object, such as an index card or credit card, without squeezing it. Avoid directly pulling the stinger out as this can burst the venom sac and release more venom.
Next, wash the area with soap and water, apply a cold compress or ice pack for 10 to 20 minutes, and take Tylenol to ease the pain and Benadryl for the itch.
Dr. Yong H. Tsai is board-certified in rheumatology, allergy and clinical immunology and has been practicing in this area for several years. Send questions to Dr. Tsai in care of mailto:accent@news-jrnl.com You also can check the Web site: www.arthritis-allergy.com
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