Last update: 31-Jul-2014 6:00 pm
Thursday, July 31, 2014
Trinidad & Tobago Guardian Online
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Stings can be life-threatening
Stings and bites from insects are common. They often result in redness and swelling in the injured area. Sometimes a sting can cause a life-threatening allergic reaction. Insects do not usually attack unless they are provoked. Most bites and stings are defensive. The insects sting to protect their hives or nests. A sting or bite injects venom composed of proteins and other substances that may trigger an allergic reaction in the victim. The sting also causes redness and swelling at the site of the sting.
Insect bites, allergies and diseases
Bees, wasps, hornets, yellow jackets, and fire ants are members of the Hymenoptera family. Bites or stings from these species may cause serious reactions in people who are allergic to them. Death from bee stings is three to four times more common than death from snake bites. Bees, wasps, and fire ants differ in how they inflict injury. When a bee stings, it loses the entire injection apparatus (stinger) and actually dies in the process. A wasp can inflict multiple stings because it does not lose its injection apparatus after it stings. Fire ants inject their venom by using their mandibles (the biting parts of their jaw) and rotating their bodies. They may inject venom many times. In contrast, bites from mosquitoes typically do not cause significant illnesses, unless they convey “vectors,” or microorganisms that actually live within these mosquitoes. For instance, malaria is caused by an organism that spends part of its life cycle in a particular species of mosquitoes. West Nile virus is another disease spread by a mosquito.
Lice can transmit epidemic relapsing fever, caused by spirochetes, while Leishmaniasis, caused by the protozoan Leishmania, is carried by a sand fly. In unsanitary conditions, the common housefly can play an incidental role in the spread of human intestinal infections (such as typhoid and bacillary and amebic dysentery) by contamination of human food. Tularemia can be spread by deer fly bites, the bubonic plague by fleas, and the epidemic typhus rickettsia by lice. Various mosquitoes spread viral diseases (such as equine encephalitis; dengue and yellow fever in humans and other animals).
Ticks can transmit Lyme disease and other illnesses through their bites or stings, and other insects such as chiggers and mites typically cause self-limited localised itchiness and swelling.
Insect bites symptoms
The response to a sting or bite from insects is variable and depends on a variety of factors. Most bites and stings result in pain, swelling, redness, and itching to the affected area. The skin may be broken and become infected if the bite area is scratched. If not treated properly, these local infections may become severe and cause a condition known as cellulitis.
You may experience a severe reaction beyond the immediate area of the sting if you are allergic to the bite or sting. This is known as anaphylaxis. Symptoms of a severe reaction include hives, wheezing, shortness of breath, unconsciousness, and even death within 30 minutes. A sting on the tongue may cause throat swelling and death because of airway obstruction. Stings from large hornets or multiple (hundreds or thousands) bee stings have been rarely reported to cause muscle breakdown and kidney failure. Bites from a fire ant typically produce a pustule, or a pimple-like sore, that is extremely itchy and painful.
When to seek medical care
If you start to experience symptoms that are not just at the site of the bite or sting (and you don’t have a history of severe reactions), seek medical attention. These symptoms may progress to fatal anaphylactic shock. Hives are the most common systemic symptom. They appear as irregular, raised, red blotchy areas on the skin and are very itchy. If hives are the only systemic symptom present, they are often treated at home with an antihistamine.
If the bite appears infected (redness with or without pus, warmth, fever, or a red streak that spreads toward the body), see a doctor. People who have a history of severe reactions should go to the nearest hospital’s emergency department after a bite or sting if they experience any symptoms. Those who have no history of severe reactions should also go to the emergency department if they experience wheezing, shortness of breath, chest tightness or pain, sensation of the throat closing or difficulty speaking or swallowing, faintness or weakness, infection.
Self-care at home
Treatment depends on the type of reaction. If there is only redness and pain at the site of the bite, application of ice is adequate treatment. Clean the area with soap and water to remove contaminated particles left behind by some insects (such as mosquitoes). These particles may further contaminate the wound if not removed. Refrain from scratching because this may cause the skin to break down and an infection to form. You may treat itching at the site of the bite with an over-the-counter antihistamine such as diphenhydramine (Benadryl) in cream or pill form. Calamine lotion also helps relieve the itching.