In North Florida, insect encounters are a commonplace occurrence; insect allergy is a frequent concern seen in the office of an allergy & immunology physician. The most common insects that may cause allergic reactions include those of the order Hymenoptera: yellow jacket, hornet, wasp, honey bee, bumble bee and fire ant.
A normal reaction after an insect sting is mild redness and swelling at the sting site — little is needed to manage such reactions. Large local reactions differ from normal reactions and may also be confused with allergic reactions. Large local reactions are characterized by redness and swelling, not only at the site of the sting but also extending to the surrounding area. Such reactions typically peak within 1-2 days of the sting before resolving over the next few days, but they can last as long as 10 days. Antihistamines generally improve the symptoms of large local reactions, but some individuals may be best treated by a short course of steroids such as prednisone.
A systemic allergic reaction, classified as anaphylaxis due to an insect sting, is characterized by acutely reduced blood pressure plus skin or mucosal reactions (e.g. hives, itching or flushing, swollen lips, tongue), gastrointestinal symptoms (e.g. vomiting, painful cramps), and/or respiratory symptoms (coughing, wheezing, shortness of breath). If left untreated, such a severe (anaphylactic) allergic reaction can result in death. Research shows that about 0.4 percent to 3 percent of people suffer from these severe anaphylactic reactions. According to research published in the Journal of Allergy & Clinical Immunology, about 50 recognized fatalities occur annually in the United States due to allergic reactions to insect stings, and some unexplained deaths may be due to these reactions as well.
There are several management strategies for insect allergies:
• Avoidance: It is important to avoid these insects. They are more likely to sting if their homes are disturbed. Thus, it is critical to have nests around the home or workplace removed by a trained professional. Food will also attract insects. Try to be mindful when cooking, eating or drinking outdoors. It may be best to avoid perfumes or colognes when outdoors. Make an effort to wear closed-toe shoes and avoid going barefoot.
• Acute treatment: Rapid treatment of acute anaphylaxis with epinephrine can prevent progression of symptoms and death after a sting occurs. This critical therapy is commonly administered in the form of an auto-injectable epinephrine device (e.g. Epi-Pen, Auvi-Q, Twinject, Adrenaclick) prescribed by a physician. Patients, parents, caretakers, schools, etc. should be educated on the device use and indications, and expiration.
• Desensitization: The most effective treatment for the prevention of systemic allergic anaphylactic reactions is venom immunotherapy (VIT). VIT is a series of venom injections, initially at a low dose and increasing to a concentration high enough to allow the individual to be tolerant of a sting. This enables a person’s immune system to be “trained” not to have a systemic allergic reaction. If dosed properly, research has shown that VIT can be greater than 95 percent effective in preventing systemic allergic reactions to stings. This therapy is typically administered in office by a physician who is board certified by the American Board of Allergy & Immunology.
There are many reasons to be outdoors in beautiful North Florida. However insect stings can take the fun out of these special moments. Please take appropriate precautions to prevent insect stings and understand the difference between a normal and abnormal reaction. This will help you determine when to seek medical attention promptly.
Steve Dorman, MD, is a practicing physician at Family Allergy & Asthma Consultants and is board certified by the American Board of Allergy & Immunology. He is a member of the American Academy of Allergy, Asthma, and Immunology, the American College of Allergy, Asthma, and Immunology, the Florida Allergy Asthma and Immunology Society, the Florida Medical Association, and the Duval County Medical Society.