Insect bites

I always get lots of bites from insects and they normally end up infected. Why is this and what should I do?

Stings and bites from insects are common. They often result in redness and swelling in the injured area. Sometimes a sting can cause a lifethreatening allergic reaction.

Insects do not usually attack unless they are provoked. Most bites and stings are defensive. The insects sting to protect their nests.

A sting or bite injects venom that may trigger an allergic reaction in the victim. The sting also causes redness and swelling at the site of the sting.

Stings from bees, wasps and hornets may cause serious reactions in people who are allergic to them. Death from bee stings is three-four times more common than death from snake bites.

When a bee stings it loses the entire injection apparatus and actually dies in the process.

A wasp can inflict multiple stings because it does not lose its injection apparatus after it stings.

In contrast, bites from mosquitoes typically do not usually cause significant illnesses un- less you are in an area where they carry malaria.

Leishmaniasis is carried by a sand fly. Ticks can transmit Lyme disease and other illnesses through their bites or stings. Other insects such as mites cause self-limited localized itchiness and swelling.

Serious bites from spiders, which are not insects, can be from the black widow or brown recluse.

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.

A sting on the tongue may cause throat swelling and death because of airway obstruction.

When to seek medical care

If you start to experience symptoms that are not just at the site of the bite or sting, seek medical attention. Hives are the most common systemic symptom. They appear as irregular, raised, red blotchy areas on the skin and are very itchy.

If the bite appears infected (redness with or without pus, warmth, fever, or a red streak that spreads toward the body), see a doctor as antibiotics may be required.

If you don't know what bit you, it is important to keep watching the area closely to be sure it does not become infected. Call your doctor if there is an open wound, which may suggest a poisonous spider bite.

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 have any of the following symptoms: Wheezing Shortness of breath Chest tightness or pain Sensation of the throat closing or difficulty speaking or swallowing Faintness or weakness Infection (If the wound appears infected and you are not able to reach your doctor, seek care at a hospital.)

Treatment

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 antihistamine cream or tablet which can be bought over the counter. Calamine lotion also helps relieve the itching.

Itching is the main symptom to control with insect bites. Topical antihistamines and anaesthetics are for quick temporary relief; hydrocortisone cream has slower onset, but longer effect.

Ibuprofen Gel. For pain and swelling from insect stings, is an excellent anti-inflammatory with quick onset.

Hydrocortisone cream 1% improves both itching and swelling. It has anti-inflammatory effects, not just symptomatic relief like the topical anaesthetics. However, it does take longer for full effect than topical anaesthetics.

Xylocaine Gel 2% for immediate relief from surface itching and pain.

Any systemic reaction should be seen by a doctor immediately. This includes hives wherever they may occur, swelling in the face, shortness of breath or wheezing, difficulty swallowing, and lightheadedness or fainting.

These usually occur within minutes to an hour after the sting. Steroids are also often prescribed. Oral antibiotics may be given for infected bite wounds. After emergency treatment, antihistamines are taken for a short period of 3-5 days.

Prevention

You can minimize your exposure to insect bites by changing your patterns of activity or behaviour. Mosquitoes are most active in twilight periods at dawn and dusk or in the evening, so avoid outdoor activity during these periods.

Wear long-sleeved shirts, long pants, and hats to minimize the areas of exposed skin. Shirts should be tucked in. Use insect repellents. Repellents applied to clothing, shoes, tents, mosquito nets, and other gear will enhance protection.