Bed Bug Bites

What You Need to Know

Bed bug bites are a great inconvenience. The pests sneak in during the night unless they are absolutely starved for a blood meal, feed without waking the victim, and retreat leaving only the allergic reaction they cause (in approximately 80% of humans). Bed bugs are cryptic, agile creatures that are very good at concealing their presence.

Bed bug bites are well documented visually on many websites and in the media. The only confirmation that a skin reaction is a bed bug bite is if there is confirmation that there are viable insects accessible to humans. It is impossible to look at a welt or rash and positively identify it as a bed bug bite. Even trained physicians cannot diagnose skin reactions as bed bug bites just by examining the bites.

Cannot Feel the Bite
People cannot feel bed bugs biting because the bed bugs have a natural anesthetic that it injects. This allows the bed bug to feed without interruption. For this reason, the sleeping victim has no indication that a bed bug is feeding.

What Do Bed Bug Bites Look Like?

Bed bug bites on people who react to bites can look like mosquito bites or like larger welts similar to what you may see in an allergic reaction.

what bites look like

bites on leg
bed bug bites on leg
bites on arm
bed bug bites on arm

Multiple Bites in a Row
Sometimes, bed bug bites are seen in a line. This shows the track or path of the bed bug which might feed on blood at one spot and then move to another in the same vein. This pattern is sometimes called “breakfast, lunch, and dinner.” It is also possible for bed bugs to feed just at one location.

3 bites in a line
three bites in a row

Droppings or Smears of Blood
As bed bugs feed to their fill, or repletion, they usually will remain attached for three to ten minutes. They may also void part of their blood meal as they feed so there are droppings of partially digested blood from the back end as the bed bug feeds on the front end. The droppings are not dangerous but may appear on the skin or clothing. If the bed bug voids after feeding, smears of partially digested blood may be found on sheets or linens.


Likely, someone suffered a night of bites and now shows the symptoms spread across their body. Bed bugs feed anywhere there is exposed skin. The saliva transferred during feeding is what causes the allergic reaction seen is most of us. Reactions vary from mild to more severe rashes and hives.

Not Always Visible
Bed bug bites are not visible on all people. People react differently and some have no visible reaction at all.

Others react with hive-like symptoms. There are documented cases where two people spend the night in the same bed and one is bitten and covered with welts and the other has no reaction. Generally, if there is a skin reaction, it can lead to itching with the degree of itching varying from person to person.


bed bug welts
welts on leg

Bed bug bites may result in what appears to be a rash or welt. Usually there is a feeding spot with a reddish area surrounding the bite site. That reddish area is frequently considered a “rash” either by itself or as a line of bed bug bites and their associated redness.

Not Everyone Reacts the Same Way
A mysterious characteristic of bed bug welts is that the reaction will vary from person to person. Some people react by developing huge welts and others develop no welts whatsoever. Some people also react quickly and others take days to react.

Time for Welt to Show Up
One worthwhile note about bed bug bites is that the bites can take days to manifest into welts or reactions when the human is not regularly bitten. After the antigen is generated from repeated bites, then bed bug bites manifest into welts or irritation from just about immediate to a few days.

This is worth noting since welts might appear days after being bitten with the blame placed on the previous night’s location when the bites occurred at a totally different location days prior.

When people are bitten for the first time, it is possible that no welts will occur at all. As people get bitten more often, there is a greater chance of antigen development and this is when the welts form.

There are also recorded cases of a series of bed bug bites which resembles measles or chicken pox. These appear to be random bites on exposed skin. The severity of a rash can depend on how many insects fed on a person, how that individual reacts to the bed bug bites, and whether the rash is particularly itchy which can result in scratching leading to increased redness or “rash” and even open wounds.

Image of red wounds from bed bug bites:
bed bug bite on arm

It is also possible that bed bug bites can be misdiagnosed ultimately leading to a false sense that a rash is from bed bugs when in fact the rash is an indication of a more serious disease. Rashes similar to bed bug bites can be indications of shingles, eczema, etc.

Note that no physician, regardless of their skill, can diagnose welts or reactions as caused by bed bugs. The entire puzzle must be evaluated including whether bed bugs were found in the area.


Similar to a mosquito bite, the bed bug bite will usually itch. Standard healing time for the symptoms of bed bug bites is a few days to a few weeks. During this time is when itching will occur.

It is important to not scratch the inflamed areas. If scratched extensively, the healing time of the symptomatic areas could be extended or the area could become infected.

Temporary relief from itching may be achieved using an anti-itch cream which can be suggested by a physician or pharmacist. Any rash associated with bed bugs or other source must be taken seriously and if possible examined by a medical professional to determine if medical treatment is appropriate to reduce itching.

Currently, no information suggests that bed bugs can be repelled by insect repellent. They are attracted to warmth and the body chemistry of humans, but may also be attracted to carbon dioxide.


Do They Spread Disease?
Bed bugs harbor nearly thirty human pathogens; however, there is no indication that bed bugs spread disease. There are recorded instances of bed bug bites becoming infected due these are due to extreme itching and lesions caused by scratching.

Do Bed Bugs Leave a Mark?

Bed bug bites can be irritating, itchy, or even become open lesions from scratching. However, bed bug bites are not the source of any known disease. Several years ago, a paper was published reporting on a study in The Gambia in Africa in the 1990s. The study examined whether bed bugs play a role in transmission of Hepatitis B. After control measures were performed, the incidence of Hepatitis B did not change so it was concluded that bed bugs do not transmit this disease either through biting or by contacting skin broken by itching.

There are situations where scratching a bed bug bite to the point of bleeding may result in scarring. This is pretty rare; however, if possible, people should be discouraged from scratching bed bug bites, especially to the point of causing an open wound. Open wounds should be treated by an antibiotic topical cream or other product suggested by a physician or pharmacist.

The elderly are particularly susceptible to scratching and if they are predisposed to bleed easily, wounds can occur. Children are also likely to scratch to the point of abrasion.

Psychological problems are generally temporary but it is commonly found that people who have experienced bed bugs can have symptoms resulting in depression, frustration, and even thoughts of suicide. While suicide is not common, the frustration level is such that some victims readily talk about deep depression and suicide suggesting that bed bug marks are a symptom of deeper concern.