MedlinePlus Medical Encyclopedia: Fleas

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Fleas

Contents of this page:
Illustrations Alternative names Definition Causes, incidence, and risk factors Symptoms Signs and tests	Treatment Expectations (prognosis) Complications Calling your health care provider Prevention

Illustrations

Flea

Insect, the basic features of adults

Flea bite - close-up

Alternative names Return to top

Dog fleas; Siphonaptera

Definition Return to top

Fleas are wingless, blood-sucking insects that feeds on dog, cats, humans and other species.

Causes, incidence, and risk factors Return to top

Fleas prefer dog and cat hosts, but in the absence of a preferred host will use humans or other available animals as a host. Pet owners may not be bothered by fleas until their pet is away for an extended period of time and the fleas, in the absence of their normal host, begin to bite the owners. Bites frequently occur around the waist, ankles, armpits, and in the bend of the elbows and knees.

Symptoms Return to top

Rash with small bumps that itch and may bleed
- Located on the armpit or fold of a joint (at the elbow, knee, or ankle)
- The amount of skin affected increases over time (enlarging skin rash or lesion) or the rash spreads to other areas
- When pressed the area turns white (blanches to touch)
Itching can be severe
Itching can be generalized or restrictied to a skin rash
Hives
Swelling only around a lesion (sore) or injury
Skin folds such as under the breasts or in the groin may be affected (intertrigo)

Note: Symptoms often begin suddenly (within hours).

Signs and tests Return to top

No testing is necessary.

Treatment Return to top

The objective of treatment is to break the flea life cycle by treating the home, the pets, and the outside environment with insecticide. Home foggers and flea collars are not always effective. Birds and fish must be protected during spraying. If home treatments are ineffective, professional extermination may be needed.

Calamine lotion helps relieve itching.

Expectations (prognosis) Return to top

Once fleas are established, eliminating them requires persistence. The problem will continue until the fleas are eliminated.

Complications Return to top

Scratching can lead to a secondary skin infection.

Calling your health care provider Return to top

Apply home treatment and call your health care provider if there are signs of complications.

Prevention Return to top

Prevention may not be possible in all cases. Use of insecticides may be helpful if fleas are common in your area. Professional extermination may be necessary in some cases.

Update Date: 4/22/2003

Updated by: Elizabeth Hait, M.D., Department of Pediatrics, Rainbow Babies and Children's Hospital, Case Western Reserve University, Cleveland, OH. Review provided by VeriMed Healthcare Network.

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