Fleas, one of man's peskiest attackers, are bloodsucking parasites that feed on dogs, cats, man, and many other animals. Unfortunately, we humans are susceptible to assault by fleas from other humans as well as by fleas from dogs and cats. Like body lice, fleas spend most of their time away from the host animal, attacking only periodically to feed. Flea saliva can be highly allergenic for some individuals.

Flea bites typically occur in groups or clusters on the arms, forearms, waist, buttocks, thighs, and lower legs. The ankles are an especially favored site. Individual bites appear pimplelike or hivelike and possess pinpoint-sized blood centers. Itching can be nerve-racking. In general, the severity of the skin reaction is a poor indicator of the number of fleas present. In other words, some people in contact with only a few fleas will develop severe allergic reactions, while others exposed to a heavy infestation may be completely symptom-free.

Topical corticosteroid preparations usually suffice to alleviate itching. On occasion oral antihistamines may be needed. But the trouble is far from over unless the fleas are eradicated. This is often no small task because fleas can remain alive for several weeks to as long as a year without feeding, and for every one seen on the body, there are probably between ten and one hundred others somewhere in the environment. This means that carpets, furniture stuffing, bedding, baseboards, and crevices where fleas typically reside need to be thoroughly sprayed with pyrethrin (RID) or commercial insecticides. Following that, you must vigorously vacuum these areas to remove surviving eggs and cocoons, which tend to be more resistant than adult fleas to the insecticides. Severe infestations of the home often require professional exterminators. Infested pets should of course be examined by a veterinarian and treated accordingly. Flea collars are not useful once your home has become infested and thus should not be relied on.