Wed, 06 Aug 2003

How to avoid and treat mosquito bites in children

Donya Betancourt, Pediatrician,

Mosquitoes wouldn't be such a problem if it weren't for the blood-sucking habits of the females. The males -- and often the females -- feed on plant nectar, but the females also depend on a bloody meal to get the protein they need for their eggs to develop, which they will lay on the surface of still water.

Meanwhile, mosquitoes are known to pass blood-borne illnesses from one victim to another. They are a major health hazard and are responsible for the transmission of yellow fever, malaria, dengue fever, encephalitis (infection of brain tissue) and many other serious diseases.

In parts of the world where mosquito-transmitted diseases are uncommon, it is their bite that presents the greatest annoyance. Infants and children are bitten more by mosquitoes than by any other insect.

The mosquito's saliva contains digestive enzymes and anticoagulants -- substances that prevent blood from clotting. In fact, the first bite does not cause a reaction in an individual. It is only through subsequent bites that the person becomes sensitized to the foreign proteins, and small, itchy, red bumps appear about 24 hours later.

With repeated mosquito bites, some people become insensitive again, as though they had received allergy shots. Some older children and adults even have no reaction to mosquito bites -- unless they go for a long time without being bitten, then the process can start again.

Other people, on the other hand, can become increasingly allergic with repeated stings. They can develop large, blistering or bruised inflammatory reactions. For these people, avoiding being bitten is the best.

When outdoors, wear light clothing that covers most of the body, keeping as much of the skin and hair covered as is practical. Avoid bright, floral colors. Khaki, beige and olive have no particular attraction for mosquitoes. They are also attracted by some body odors, and for this reason they choose some individuals over others in a crowd.

Avoid fragrances in soaps, shampoos and lotions. All other things being equal, mosquitoes will choose children as their victims rather than adults.

Many species of mosquito prefer biting from dusk until dawn, and they tend to bite more when the weather is hot or humid.

Citronella candles may be useful when playing outside. Some studies suggest that taking 25mg to 50 mg of thiamine (vitamin B1) three times a day is effective in repelling mosquitoes. This common vitamin apparently produces an odor that is not detectable by humans, but is disagreeable to pregnant mosquitoes.

It seems to be especially effective for those people with large allergic reactions. It takes about 2 weeks before the odor generated by thiamine fully saturates the skin.

The next step is treatment after being bitten. The mainstays of treatment are cool compresses, antihistamines, anti-itching compounds and anti-inflammatory medicines. For a cool compress, apply an ice pack wrapped in a towel or soak a washcloth in cold water and press it on the bite.

For children, ask your doctor to help you select an appropriate antihistamine. You might have to balance strength versus drowsy side effects. Zyrtec, a newer antihistamine for children, usually works very well, while not being too sedating.

The simplest anti-itching compound is a paste made of baking soda and water. Use just enough water to make a sticky paste, and spread it on. Calamine lotion works in a similar way, and its effect usually lasts longer.

For anti-inflammatory treatment, ibuprofen or naproxen can reduce redness, pain, itching, swelling and fever. Topical steroid creams of various strengths can also be useful. Occasionally, reactions to mosquito bites can be severe enough to warrant systemic steroids.

Living in Southeast Asia means we will constantly need to protect and treat our children from mosquito bites. As parents, we want to do our best to help our children prevent scarring, infections and aggravating bites by keeping the bites covered and protected from scratching.