Bed bug bites: How to identify them, get relief, and prevent future bites
- Reviewed by Howard E. LeWine, MD, Chief Medical Editor, Harvard Health Publishing
Bed bugs are a nuisance that can cause itchy, uncomfortable bites. Bed bug infestations can be tricky to identify and difficult to eliminate.
What are bed bugs and what do they look like?
Bed bugs are small, parasitic insects that need human or animal blood to survive. They ingest this blood when they bite. Though they do not transmit disease, their bites can be irritating. Bed bugs are found all over the world and are difficult to control.
Even if you have a bed bug infestation, you may not see many bed bugs because the pests are primarily nocturnal, coming out to feed during the night. In addition, their small size allows them to hide in hard-to-reach places such as seams of mattresses or inside cracks or crevices.
Bed bugs look different depending on their life stage:
- Adult bed bugs are small, oval, flat, reddish-brown in color, and wingless. They are approximately the size of an apple seed (3/16 to 1/4 inch long). Bed bugs swell and become more elongated after feeding.
- Young bed bugs are called nymphs. They are smaller, translucent, or whitish-yellow in color. They can be nearly invisible if they have not recently fed (the blood gives them a reddish-brown color).
- Bed bug eggs are pearl white and are very small, about the size of a pinhead.
What do bed bug bites look like?
A bed bug bite may appear red and slightly swollen. The bite marks may be random, appear in a straight line, or in a zigzag pattern. Bite marks often appear in clusters of three to five bites. Bed bug bites may be mistaken for mosquito, flea, or spider bites, or for a rash or hives.
Bed bug bite symptoms
Most people do not immediately realize they have been bitten by bed bugs because the insects inject an anesthetic and an anticoagulant (a substance that prevents blood from clotting), which make it harder to detect the bite. In some cases, it can take up to 14 days after the initial bite for a bite mark to appear.
Some people never show bite marks or may develop just a small bite mark. Others may experience bites that are itchy, irritating, red, and swollen. Some people have an allergic reaction to bed bug bites, developing large, painful, swollen bite marks. On very rare occasions, an allergic reaction to bed bug bites can cause anaphylaxis.
Bed bug bites may also cause insomnia, anxiety, and skin infections caused by excessive scratching.
Bed bug bite treatment
Bed bug bites are not dangerous and usually heal on their own within a week or two. Excessive scratching, however, can lead to infection at the site of the bite. It's best to avoid scratching the bites to reduce the risk of infection.
The American Academy of Dermatology (AAD) recommends the following measures to manage uncomfortable bed bug bites.
- Clean the bite marks with soap and water.
- Apply an over-the-counter corticosteroid cream or calamine lotion to help with itching and inflammation.
- Use an oral antihistamine, if needed, for symptom relief.
You should see your doctor if you have many bites, blisters, an allergic reaction, or signs of a skin infection (redness, puss, oozing).
Bed bug bite prevention
The best way to prevent bed bug bites is to avoid bed bugs in the first place. Bed bugs have a tendency to move with us and our possessions. Because bed bugs need human or animal blood to survive, they prefer to live close to their host, near nests (or beds, in the case of humans).
Expert hitchhikers, bed bugs can infest new locations by hiding in luggage, clothing, or other items that people carry with them. They can move from room to room (or apartment to apartment) through floors, door gaps, electrical outlets, or through furniture, books, or clothing.
Bed bugs can also be transported into your home with secondhand furniture or household items. Always inspect these items closely before bringing them inside your home.
Traveling is another means for bringing bed bugs into your home. Be aware of the signs of a bed bug infestation when you travel so you don't unknowingly bring the pests home with you. The National Pest Management Association (NPMA) recommends these tips:
When traveling:
- Avoid placing luggage on carpets, beds, or upholstered furniture. Try to place your luggage in the bathtub while you inspect the room for signs of bed bugs.
- Pull back bed sheets, inspect mattress seams and box springs. Look for small dark blood stains, blackish specks, or shed bed bug skins.
- Check behind the headboard, inside dresser drawers, sofas, and chairs.
At home:
- Look for bed bugs in suitcases and bags outdoors before bringing them inside your home.
- Vacuum your suitcase or use a garment hand steamer to kill any bed bugs or eggs.
- Wash and dry all clothes — even unworn ones — on hot cycles.
Handling a bed bug infestation
If you suspect a bed bug infestation, look for the following evidence:
- bed bugs in the folds of mattresses, bedding, furniture, and anywhere else where they can hide
- bed bug skins, or exoskeletons, that have been shed
- small, dark, rust-colored spots and black specks
- a sweet, musty odor.
If you have a bed bug infestation, contact a qualified pest control professional. Also known as a bed bug exterminator, this type of expert can inspect your home for bed bugs and eliminate them.
Bed bug spray
If you choose to handle a bed bug infestation on your own, there are more than 300 products approved by the Environmental Protection Agency (EPA) that can be used by consumers to control bed bugs. You can use the EPA's Bed Bug Product Search tool to find the best pesticide for your needs.
About the Author
Jenette Restivo, Health Writer; Assistant Director for Digital Content Creation and Engagement, Harvard Health Publishing
About the Reviewer
Howard E. LeWine, MD, Chief Medical Editor, Harvard Health Publishing
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