Spider Bite Pictures

An expanding lesion, like the one in the picture, is common in brown recluse bites, but there are many other possibilities to consider. Some skin infections can lead to lesions like this. The only way to tell for sure is to have it evaluated by a medical professional.

One of the things that set bites apart—whether from spiders or other bugs— from infections is the "bullseye" pattern of discoloration. It shows up as concentric rings of discoloration.

It's common in tick bites, especially those that later turn into Lyme disease, and can also be present for spiders.

Ticks, scorpions, and spiders are all arachnids.

Black widows have fangs, almost like miniature snakes. Soon after a black widow spider bites you—before any reaction starts—you might be able to see two small holes like those in this image.

Black widow venom can cause muscle spasms and heart disturbances, but if you have a black widow spider bite, rest assured that they are rarely fatal. The most common symptoms after a bite (besides the pain of the bite itself) are:

• Abdominal pain
• Muscle cramps/soreness
• Soreness and redness around the bite
• Irritability/agitation

High blood pressure is also common from black widow spider bites, although it rarely causes any problems for the patient. Most of the symptoms are treated individually. An antivenin (spider poison antidote) is available for black widow spider venom, but it's not really necessary for most patients.

Brown recluse bites can go unnoticed, or they can lead to severe pain 2 to 8 hours after the bite. In some cases, patients report feeling a "pinprick" at the site of the spider bite. In true cases of loxoscelism (medical terminology for the condition caused by brown recluse bites), skin tissue that develops could take several months to fully heal and the scars may remain. Generally, brown recluse bites are much less likely to cause significant injury than black widows. 

It's nearly impossible to say for sure if a spider bite comes from a brown recluse without the use of a lab test. However, there are some telltale signs that can be used to rule out the possibility of a brown recluse bite.

NOT RECLUSE is an acronym for the signs that a wound or lesion is not caused by a brown recluse bite. It stands for:

• Numerous
• Occurrence
• Timing
• Red center
• Chronic
• Large
• Ulcerates too early
• Swollen
• Exudes moisture

The presence of any of these is an indicator that the wound isn't from a brown recluse. The presence of two or more of these signs almost guarantees that it's not. Let's take a look at each one.

Multiple bites are not typically from spiders, especially not a brown recluse or black widow. In cases with so many bites, consider bugs that travel in groups, like mosquitoes, bedbugs, or chiggers, for example.

In order to be a brown recluse bite, the way the bite happened is very important to the story. If the bite occurred because the patient disturbed a spider by moving old boxes in the attic, that's much more likely than getting a bite in the yard.

Recluse spiders have that name for a reason; they don't like crowds. They hide in really out of the way, dark places. Bad luck in the backyard, for example, could be due to poison ivy or spiders. It could also be a result of chiggers, which like to get into boots and socks to bite their prey.

When it happens matters, too. If a bite doesn't happen from April to October, the chance that it's from a brown recluse are slim to none. Brown recluses are notoriously inactive during the rest of the year.

A red, inflamed center is not an indicator of a brown recluse bite. Loxoscelism (brown recluse envenomation) is known for having a dark, flat center.

A swollen, hot area can easily be a staph infection. There is a possibility that it's a bug bite, but skin infections are even more likely. Lest you think that staph infections can be the result of a spider bite, it's probably not the case. At least one study found that spiders do not regularly carry bacterial infections.

If it takes a really long time for the lesion to heal, it might not be a brown recluse bite. They've got a reputation for lasting a while, but most brown recluse bites heal within three weeks and the biggest of them heal within three months.

A line drawn around the lesion, as shown in the picture, is a common method for keeping track of an expanding rash or area of swelling. Be sure to note the time and date when a line is drawn to know how fast the lesion expands.

Brown recluse bites are known for having necrosis (dead tissue) in the center of the lesion. However, the necrosis is not going to be bigger than 10 centimeters across (four inches).

A lot of infected sores are identified—even diagnosed—as spider bites. In truth, unless you have a spider to identify as the culprit, the odds are against a spider bite. It's much more likely that a non-spider bug did the biting in this case.

If the lesion grows or continues to get worse over a 24 hour period, it's worth taking a trip to see the doctor. If not, it's probably fine just to keep it clean and keep an eye on it.

A brown recluse bite will eventually break the skin (ulcerate), but if it happens before the week is out, it's probably not a brown recluse. Sometimes, it's not really obvious that the lesion ulcerated, other than the fact that it develops a crust.

So, if it's bleeding or crusty and it hasn't been a week, it's probably something other than a brown recluse bite.

Swelling typically indicates something other than a brown recluse bite. Below the neck, brown recluse bites do not result in significant swelling. Above the neck is a different story. Bites on the eyelids and other very soft tissues of the face often swell after a recluse bite.

Any bug bite can lead to swelling from allergic reaction or envenomation.

Brown recluse bites are known for being dry in the center. If it's oozing pus or moisture, it's very unlikely to be a brown recluse bite.