Signs and symptoms of bedbug bites will usually affect only the surface of your skin, revealing themselves as small itchy red bumps known as papules or wheals. You might find the lesions in a linear or clustered fashion, indicative of repeated feedings by a single bedbug.

Some people may develop allergic reactions or larger skin reactions such as:

• Large, itchy wheals up to 8 inches (20 centimeters) across
• Blister-like skin inflammations
• Groups of small, swollen sacs of pus
• Skin rashes similar to hives

©1998-2009 Mayo Foundation for Medical Education and Research (MFMER). Terms of use.

Bedbugs will feed on any mammal, including cows and dogs. In North America, migratory birds and bats have been sources of infestation.

More recently, as world travel has increased, bedbugs are finding their way into the home through luggage and clothing worn abroad.

Another contributor to the resurgence of bedbugs in the West is changing pest-control practices. Sixty years ago the common use of DDT — which kills most insects — nearly eliminated bedbugs in the United States.

Today the use of DDT is being phased out due to human toxicity concerns. Further, current extermination practices are more insect-specific — what's toxic to a cockroach may not kill a bedbug.

©1998-2009 Mayo Foundation for Medical Education and Research (MFMER). Terms of use.

Factors that will increase your chances of a bedbug infestation:

• Climate. Bedbugs thrive in tropical areas, although they can be found in all climates.
• Type of housing. Infestation is more likely in apartments and homeless shelters — which have high turnover — than in single-family homes.
• Living with pets. Cats and dogs can carry bedbugs into the home.

©1998-2009 Mayo Foundation for Medical Education and Research (MFMER). Terms of use.

If you experience allergic reactions or severe skin reactions to your bedbug bites, see your doctor for treatment.

©1998-2009 Mayo Foundation for Medical Education and Research (MFMER). Terms of use.

Diagnosis of bites requires a history of your exposure and a physical examination of the bite areas. Because the bites can be mistaken for those of other insects or other skin problems, your doctor will need to rule out fleas, body lice and scabies before determining a diagnosis of bedbugs.

Diagnosis of a bedbug infestation in your home can be more difficult, since bedbugs are active primarily at night. If you have signs or symptoms, immediately inspect your home for the insects. Thoroughly examine crevices in walls, mattresses and furniture. You may need to perform your inspection at night when bedbugs are active.

Look for these signs:

• Discrete bloodstains on sheets and mattresses
• Specks of blood behind wallpaper or other sites of heavy infestation
• Insect excrement at the entry to hiding places in furniture crevices and walls
• An intense, sweet odor caused by bedbugs' oil secretions

©1998-2009 Mayo Foundation for Medical Education and Research (MFMER). Terms of use.

You're likely to experience only the itchy skin welts that bedbugs cause while feeding. However, some people develop more complicated reactions to bedbug bites, such as clusters of inflamed red bumps, dilation of the capillaries under the skin, formation of pus-filled blisters and hives up to 8 inches across.

A rare possibility exists that anaphylactic shock may occur as an allergic reaction to the substances the bedbug injects while feeding.

©1998-2009 Mayo Foundation for Medical Education and Research (MFMER). Terms of use.

Treatment of bedbug bites is aimed at relieving symptoms. Bites usually resolve within one to two weeks.

• Apply a topical cream, such as cortisone, to relieve itching.
• Avoid scratching to prevent infection.
• Consult your doctor if you have severe reactions. An oral antibiotic may be recommended if infection occurs. Oral corticosteroids may be recommended for severe allergic reaction.
• Take antihistamines if needed to help relieve allergic reactions.

Once your symptoms are treated, you must tackle the infestation. First, you'll need to freeze pajamas, sheets and other bedclothes for at least 24 hours or launder them in hot water of at least 97 F (36 C). Vacuum the area of infestation daily and freeze the vacuum bags for 24 hours. Insecticide sprays such as dichlorvos, permethrin and malathion must be used around cracks and crevices in your home. Lawn and garden insect control sprays may contain these insecticides, and garden stores may have permethrin. However, this difficult task likely requires a professional inspection of the bedbug habitat and subsequent extermination.

©1998-2009 Mayo Foundation for Medical Education and Research (MFMER). Terms of use.

If bedbugs are already present in your home, you can help ward off bites by wearing nightclothes that cover as much skin as possible.

To help prevent bedbugs from becoming residents in your home:

• Inspect antiques and secondhand furniture thoroughly before bringing them into your home.
• Employ the regular services of a professional exterminator.
• Use bed nets impregnated with permethrin to ward off infestation in tropical areas.
• Inspect any room you're about to inhabit while traveling.
• After you return from a trip, check your luggage for insects that might have hitched a ride.
• Change bed linens at least once a week, and wash in hot water of at least 97 F (36 C).
• Vacuum around the home at least once a week, paying special attention to areas surrounding bed and furniture posts.
• Caulk holes in floors and walls.
• Dismantle and either treat with insecticides or discard any old furniture, including bed frames and mattresses. Use insecticide sprays containing dichlorvos, permethrin or malathion around cracks and crevices in your home. Lawn and garden insect control sprays may contain these insecticides. However, professional inspection and extermination may be best.
• Eliminate any neighboring bird and bat habitats that may serve as a refuge for bedbugs, especially following an extermination attempt.

©1998-2009 Mayo Foundation for Medical Education and Research (MFMER). Terms of use.

Self-care during a bedbug infestation primarily involves comfort care for bites.

However, you may experience psychological effects due to a bedbug infestation, such as imagined itching. This is normal. And understand that a bedbug infestation is nothing to be embarrassed about. Even the cleanest, most meticulous individual can experience a bedbug problem in the home.

Should you suspect bedbugs in your home, treat any bites quickly and take immediate steps to eliminate the infestation.

©1998-2009 Mayo Foundation for Medical Education and Research (MFMER). Terms of use.