Bed Bug Bites

What bed bugs are

Bed bugs (Cimex lectularius) are flat, oval, reddish-brown insects about 5 mm (the size of an apple seed) as adults. They cannot fly or jump. They hide in mattress seams, box springs, bed frames, headboards, furniture joints, behind wallpaper and in clutter, and come out at night to feed for 3 to 10 minutes. Their saliva contains an anesthetic and an anticoagulant, so bites are usually painless at the time.

Bed bugs are found in clean and dirty homes alike. They spread by hitchhiking in luggage, used furniture and clothing, and are common in hotels, apartments, dormitories and shelters.

What bed bug bites look like

• Small, raised, red bumps or welts, 2 to 5 mm or larger
• Often in a line or zigzag of three to five bites, sometimes called "breakfast, lunch and dinner"
• Sometimes a tiny dark dot (the bite) in the center
• On skin left uncovered in bed
• On darker skin, bites may look purple or darker brown rather than red

Not everyone reacts. Some people have no visible marks at all, while others develop large itchy welts, blisters or hives. Reactions may appear within hours or up to 2 weeks after the first bites, so the bites you see may not reflect when you were exposed.

Bed bug bites vs other bites and rashes

See flea bites and scabies for more on those conditions.

Signs of bed bugs in your home

Because bites alone cannot confirm bed bugs, look for:

• Rust-colored or dark spots (crushed bugs or droppings) on sheets, mattress seams or the box spring
• Live bugs or pale shed skins in mattress seams, bed frame joints and furniture
• Tiny white eggs (1 mm) in crevices
• A musty, sweet smell in heavy infestations

Use a flashlight and a credit card edge to check seams and cracks.

Symptoms and complications

• Itching, the main symptom, sometimes intense
• Skin infection from scratching (impetigo or cellulitis): increasing redness, warmth, pain, pus or crusting
• Allergic reactions: large welts, blisters or hives. Severe whole-body reactions are rare
• Sleep disturbance, anxiety and stress, which are common and real effects of an infestation

Bed bugs have not been shown to transmit infections to people.

Diagnosis

A doctor diagnoses bed bug bites from their appearance and your history, ideally with evidence of bugs from the home. There is no test for the bites themselves. The doctor may consider other causes of itchy bumps, such as other insect bites, scabies, hives, eczema or chickenpox.

Bed bug bites treatment

Most bites heal by themselves in 1 to 2 weeks. To ease symptoms:

• Wash the bites with soap and water.
• Avoid scratching. Keep nails short and consider cotton gloves at night for children.
• Cool compresses reduce itching and swelling.
• Hydrocortisone 1% cream or calamine lotion on the bites, following the label.
• Oral antihistamines such as cetirizine or loratadine during the day, or a sedating one at night, following the label dose.
• See a doctor for a stronger steroid cream if itching is severe, or for antibiotics if bites become infected.

Getting rid of bed bugs

Treating the bites is only half the job. Bites will continue until the infestation is eliminated.

• Call a licensed pest control professional. Effective treatment usually combines inspection, heat treatment and targeted insecticides, often over several visits.
• Wash bedding and clothes in hot water and dry on the hottest setting for at least 30 minutes.
• Vacuum mattresses, carpets and furniture, then seal and discard the vacuum bag outside.
• Encase the mattress and box spring in bed bug-proof covers for at least a year.
• Reduce clutter where bugs hide.
• Do not move furniture or belongings to other rooms or homes until treated, which spreads bugs.
• Avoid "bug bombs" (foggers), which do not reach hiding places and can spread bugs.
• Do not use outdoor pesticides indoors or apply chemicals to mattresses unless the label allows it.

Prevention when traveling

• Inspect hotel mattress seams and headboards with a flashlight.
• Keep luggage on a rack away from the bed and walls.
• On returning home, wash clothes on hot, dry them on high heat, and inspect your suitcase.
• Check secondhand furniture carefully before bringing it inside.

Frequently asked questions

What do bed bug bites look like?

They are small, red, itchy bumps or welts, often in a line or cluster of three to five on skin exposed during sleep, such as the arms, neck, face and shoulders. On darker skin they may look purple or brown. Some people have no reaction at all.

How long do bed bug bites last?

Most bites fade within 1 to 2 weeks. Itching is usually worst in the first few days. Bites can last longer if they are scratched or become infected, and new bites will appear until the bugs are removed.

How do I know if I have bed bugs or something else?

Look for evidence in your bed: dark spots or blood stains on sheets, live bugs, shed skins or eggs in mattress seams and furniture cracks. Bites in lines on exposed skin suggest bed bugs. Itching in skin folds and between fingers suggests scabies.

Are bed bug bites dangerous?

Usually not. Bed bugs are not known to spread disease. The main risks are skin infection from scratching, occasional allergic reactions, and the stress and poor sleep an infestation causes. Severe allergic reactions are rare but need emergency care.

What is the best treatment for bed bug bites?

Wash the area, avoid scratching, and apply a cool compress and hydrocortisone cream. An oral antihistamine helps itching, especially at night. See a doctor if the bites become infected or the itching is severe.