Bullseye Bruises: Is It From a Spider Bite?

A lot of bumps and red sores are blamed on spiders. The reality is that without catching the spider in the act of biting you, it's nearly impossible to diagnose most sores as spider or bug bites. One exception is the bullseye pattern of bruising. This is common with bugs, especially certain types.

Not All Spider Bites Come from Spiders

tick bite bullseye pattern
Tick bites are well known for developing a bullseye pattern. CDC / James Gathany

Not all "spider bites" actually come from spiders. This classic bullseye redness pattern comes from a tick bite rather than a spider bite. In fact, this patient later developed Lyme disease.

Spider Bite Bullseye

spider bite
Very small bullseye forming on a possible bug or spider bite. Jake from Atlanta

One of the things that sets infections apart from bites—whether from spiders or other bugs—is the bullseye pattern of discoloration. It's common in tick bites, especially those that later turn into Lyme disease. The bullseye can also be there for spiders.

This bite is small, but up close you can really see the pattern of red in the center surrounded by lighter color surrounded by a red circle. Jake from Atlanta says there are "teeth marks" in the center, but that isn't readily apparent from this picture. He also says this bite was followed by dizziness that lasted for more than 10 hours. This picture was taken the next day.

Jake hadn't seen a doctor by the time he submitted this picture. It's a good idea to see a doctor anytime a bite or a rash comes with dizziness, fever, headache, weakness or confusion.

A Bite in Botswana

bite marks
Possible bite marks from an unidentified critter. AllTogetherGuy

A reader submitted this picture showing a bite he received in Botswana. The Spider Bite Picture Gallery is full of mysterious bumps and bruises that folks often blame on spiders. This image -- and the story that goes with it -- shows just how difficult it is to diagnose a spider bite unless the spider is munching along when you see it.

I did not see a doctor because I was not in any discomfort. I did ask several locals what they thought and opinions were split between a Tse-Tse fly and a spider. The wounds "sweated" for a couple of days so some thought that meant it was a spider. I am not so concerned if it was a spider, but I am worried if it was a bat since very serious consequences could develop years later.

Bats versus spiders versus Tse Tse flies? You'd think the size of the wound alone would sway you one way or the other. However, spiders can be large and bats can be small, so I can see how difficult it is to guess. The exotic nature of the region makes it even harder.

So what does one do in that situation? Look for the same thing you should watch for in any wound: signs of infection.

  • Oozing
  • Swelling
  • Redness
  • Fever/chills
  • Pain

Like with the others, it's the bullseye that makes it look like a bite.

Little Spider Bite and Big Bruise

bullseye pattern on a bug bite
It's small, but this is a classic bullseye pattern. Paul Collins

Look closely at this bullseye. In the center is a tiny red dot. It might have been a spider or maybe something else. It's hard to know for sure without a bug or spider to look at. Either way, the treatment for bug bites is the same.

Late Night and the Morning After

bullseye pattern of bruising from a bite
Left image shows a possible bite in the middle of the night and the right image shows the same lesion the next morning. Sarah

After a day of shoveling scrap wood and bark, this reader wakes from a good night's sleep feeling as if she'd been "kicked in the leg." When she woke, she expected to find a bruise but found this discoloration instead (left image).

By the next morning (right image), the discoloration has taken on a familiar bullseye pattern. Could it be a spider bite? It sure could. It could also be one of a hundred other types of bugs.

At the end of the day, this lesion develops a blister, another common feature in spider and bug bites. It will eventually burst and leave the reader with a scar she described as a "crater" when I communicated with her three years later.

Brown Recluse in the Woodpile?

faint bullseye pattern
A Little Pinch, Fever, Chills and a Headache - Could Be a Brown Recluse. Image submitted by D. C.

There aren't too many lesions blamed on brown recluse bites that I pay much attention to, but this submission from D. C. in Texas has me wondering if this is the real thing:

I felt a pinprick while collecting and chopping firewood at a ranch in South Texas. Later that night I started feeling body aches, joint pain, and chills.

For this bite actually being the work of a brown recluse: the incident happened within the known habitat of the brown recluse in a wood pile. It's almost cliche.

Against this bite being the work of the dreaded brown recluse: no brown recluse. There was no spider found at the scene of the crime. Of course, that doesn't mean it wasn't a brown recluse bite; it just means there's no way to know for sure.

Spider in the Shower

spider bite in the shower
A spider bite in the shower. Rosebuds1981

Rosebud submitted this picture of a bite on her arm that landed her in the hospital. In her submission, she writes how she caught the spider in the act:

I was just getting out of the shower and had wrapped my towel around me when I felt something sting my arm. That's when I brushed the spider off my arm and saw it fall to the floor. That happened about eleven o'clock pm.

The next day it was itching but I had no pain. By the third day it hurt a little, but by the fourth day my whole arm was throbbing.

Catching a spider in the act is rare. Usually, the person doesn't even know the spider was around. Even though this reader saw a spider and believes it fell from her arm, there is still the possibility this is something else entirely. When it's this swollen, a trip to the doctor is a good idea.

Possible White Tail Spider Bite

white tail spider bite
A possible white tail spider bite from Australia. Sue Shelley

The person believes this is a white-tail spider bite. However, she has a history of reactions to bug bites. Without a positive identification of the bad guy, this could be almost any bug bite.

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