Bed bug bite marks are caused by a stylet located on the insects head. The stylet punctures the skin and is inserted into the skin until a blood supply is located (it isn't technically a bite.) As part of the feeding process, the bedbug will inject a substance into the host that acts like an anesthetic, so the host doesn't feel the puncture. Each bite will have one puncture mark on the skin.
Bites usually occur at night in areas not covered by clothes such as the neck, shoulders, arms and lower legs. Bites tend to not occur on the face or bottoms of the feet. It is possible for bedbugs to bite underneath loose clothing.
Some people, but not all, will have an allergic reaction to the substances injected into the skin. This ranges from skin irritation, minor papules (small pimple or red skin irritation), to in rare cases, large itchy welts and skin blistering. Bed bug Bites can occur in one location or can look like a cluster or pattern of bites in a triangle, group or straight line.
Reactions to bites are seen in approximately 20% - 50% of the population. Skin reactions can occur hours or even 9 days after being bitten.
You do not need a bed bug bite cure since they go away on their own in 3 to 5 days, with the primary symptom beyond the skin reaction being itch.
Bug Bed Bite Video
Magnified view of bed bug bite mark occurring in real time.
At night, bed bugs are attracted to body warmth and the carbon dioxide created when someone breathes. They usually hide within 1 to 6 feet of host, which in most cases area areas around the mattress such as tufts and seams.
When a bed bug punctures the skin, it is thought that salivary proteins are injected into the host, which causes the allergic or immunological response (protein is called nitrophorin). Once the bed bug feeds it moves back to the closest hiding spot which can be a mattress seam or other tight space.
Bed Bug Bite Marks on Skin
Bed Bug Bite Mark Skin Reactions
The majority of people have no skin reaction or a hardly visible skin puncture where the bite occurred. This is why two people in the same bed can have a completely different reactions, with one showing no skin symptoms, while the other gets red rashes and bumps all over exposed areas of the skin.
Bed Bug Bite Mark Being Made on Skin
Each bed bug bite episode can be different, with the same individual showing a bed bug bite reaction one time, and a more pronounced reaction another.
Those that do react have a small red raised area about 2mm (.07 to .19 inches) to 5mm is diameter. These minor skin reactions usually appear within an hour and have a noticeable itch. They will go away by themselves in several days to a week. Itching can cause a skin infection, which will delay healing and require an antibiotic ointment.
Classic Triangle Pattern Bed Bug Skin Bite Reaction
Bed Bug Bites on Hand
Chronic Bite Reactions
Some highly allergic people will have more pronounced bedbug bite
marks, resulting in wheals, which are larger circular red raised areas
on the skin. These bed bug skin rash reactions can happen
immediately after being bitten or they can occur hours or days later.
Bed Bug Bite Marks on Arm
Bed Bug Bite Papules
Chronic Bed Bug Bite Cluster on Arm
Bed Bug Bite Straight Line Pattern on Arm
Cluster of Bites on Lower Leg
In very rare cases, bedbug bites can trigger asthma, skin blistering, and hives all over the body (called urticaria).
Bed Bug Bite Wheal Skin Reaction
Bed Bug Bite Blisters
Bed bug bites can occur in a straight line, triangle or other linear patterns. However, most people will not see any pattern. It is unknown if patterns of bites are caused by one or several insects.
bite marks removal
Minor bed bug bite reactions will on its own and requires no treatment. Healing will occur in less than a week. In unusual cases, bed bug welts can take several weeks to heal.
Do not scratch the bumps, to avoid infection. If reaction shows blood or pus, or do not go away, see a doctor, since the reaction may require antibiotics for infection, or allergy medications such as corticosteroids or antihistamines.
In most people. bed bug itch is the most pronounced reaction. In this case, an over the counter oatmeal based topical such as Aveeno will help. There are products available that are specifically formulated to treat bed bug itch such as All Stop and ProEcza.
Other bed bug bite treatment approaches are based on the severity of the symptoms. For example, if infection has set in, then either a topical or oral antibiotic is needed.
difference between bed bug bites and reactions from other biting insects
Bed Bug bite marks may resemble the skin bites from other insects such as mosquito
bites. Bites alone cannot be used to determine if you were bitten by bed bugs. You need to confirm that you have a bed bug problem for looking for other signs. These include fecal spots on a mattress or the capture and identification of an insect.
The following causes need to be ruled out before diagnosing bed bugs:
- chicken pox
- staphylococcus infection
- spider bites
- mosquito bites
- food allergy
- reaction to medications such as antibiotics
- scabies (diagnosed with a skin scraping)
Mosquito Bites (left) Compared to Bed Bug Bites (right)
Scabies Rash on Skin
Confirm the presence of bed bugs
Because the majority of people do not experience a bed bed bug bite reaction, they do not realize they have bedbugs in the home until the population builds to a large size, causing a major problem in the home or apartment.
As mentioned, bed bug bite marks look like bites from other insects. Call an experienced exterminator such as Home Advisor (1.877.233.1145) to confirm that you have an infestation.
You can also send a dead insect to Cornell University who will identify any insect for a small fee.
bed bug skin repellent
To avoid bed bug bites in an infested room, you can try the following tips:
- Wear a bed bug skin repellent patch. The patches work by using vitamin B1 to offset and reduce the CO2 that is emitted through skin and attracts the insects.
- Wear tight fitting clothing or reduce exposed skin areas. One tip is to wear socks to bed over the bottoms of your pajamas.
- Pull the bed 6 inches away from any wall or furniture.
- Keep blankets off the floor.
- Trap bed bugs inside the mattress and box spring by buying covers for both. Note that covers will not eliminate the insects from the room.
- Buy an inexpensive bed bug trap for each bed leg. This makes it harder for bed bugs to get to you when sleeping.
This free brochure provides additional information on how to determine if the bites on your body are from bed bugs.
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What Other Visitors Have Said About Bed Bugs
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Bed Bugs (Cimex lectularius)
and Clinical Consequences of Their Bites
Jerome Goddard, PhD
Richard deShazo, MD
Environmental Health Section
San Francisco Department of Public Health