A serious staph infection that doesn‘t respond to antibiotic treatment can develop from any wound, including a spider bite. It is also possible to mistake MRSA infections for a spider bite at first.

Bug bites and other wounds can become infected with many varieties of Staphylococcus, a group of bacteria. Alternatively, a staph infection of the skin that develops from other wounds might be mistaken for a spider bite.

This article will review how you develop a staph infection on your skin, what these infections might look like, and how to tell the difference between a staph infection and another skin injury, such as a spider bite.

You can develop a staph infection on your skin any time there is a wound or break in the skin’s surface. Some forms of Staphylococcus are found naturally on the skin and aren’t a cause for concern unless the bacteria overtakes your immune system.

When your immune system can’t keep a balance with the bacteria, an infection can develop. This may happen if you have a weakened immune system or an overgrowth of the bacteria. Cuts, scrapes, blisters, and even bug bites can all create a host site for a staph infection on your skin.

Spider bites are actually pretty rare. But they can become infected or progress to necrotic wounds that severely damage tissue.

However, experts note that what many people think are spider bites are actually bites from other pests, like fleas or bed bugs. The “bite” might even be a more serious MRSA infection.

What is MRSA?

Methicillin-resistant Staphylococcus aureus (MRSA) is a type of bacterial infection that is difficult to manage with common antibiotics. MRSA infections are caused by specific strains of staph bacteria that have evolved to become resistant to many antibiotics, earning them the nickname of superbugs.

There are certain antibiotics, like vancomycin, that are still pretty effective in treating MRSA. But experts believe these antibiotics will — in time — also lose their effectiveness against MRSA.

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MRSA-specific infections can be difficult to distinguish from other types of wound infections, regardless of what caused the original wound. Two tiny bites may be visible with a spider bite, but more noticeable symptoms usually include things like:

  • redness
  • swelling
  • pain or tenderness
  • itching
  • filled with fluid

These symptoms are typical when it comes to spider bites. Yet spider bites can also develop into more significant wounds.

Bites from certain spiders, including venomous spiders like the brown recluse spider, can cause a more severe wound that heals slowly or even leads to tissue damage.

Necrosis is the injury and death of healthy tissue. It is a common complication of venomous spider bites, and it can be difficult to tell the difference between a necrotic spider bite and an MRSA-infected bite or even other MRSA wounds.

Whether they began with a spider bite or not, MRSA wounds may appear with the following symptoms:

  • redness
  • swelling
  • pain or tenderness
  • warm to the touch
  • filled with pus
  • fever

How do you mistake MRSA for a spider bite?

MRSA infections of the skin and spider bites both typically begin as small red bumps. These bumps can be raised, hot, sore, and filled with fluid or pus.

At first, you might not notice a spider bite or the initial wound that developed into an MRSA infection. Seeing the spider itself or noticing the tiny bite holes are usually the best indicator that your wound was caused by a spider bite and not something else.

You can also differentiate between an MRSA infection and a spider bite based on what comes out of your wound. Spider bites typically drain clear fluid while MRSA wounds usually drain pus.

An MRSA infection is also likely to spread from the area where it began to surrounding skin, other areas of the body, or even your blood and bones.

Spider bites don’t always require treatment. Many bites from common spiders will heal on their own, though bites from venomous spiders can require more care.

A cold compress, topical antihistamines or pain relievers, and thorough cleansing are all recommended as first-aid treatments for spider bites.

If you get bitten by a known venomous spider, you should also include an evaluation by a healthcare professional in your first-aid plan. Bites from some spiders can cause healthy tissue to die off, which then requires much more extensive treatment or even reconstruction.

Home remedies may help MRSA wounds to some extent, but they really require the use of powerful antibiotics. Yet not all antibiotics work to treat MRSA wounds because the bacteria that cause them have become resistant to many of these medications.

Antibiotics currently recommended for treating MRSA include:

  • vancomycin
  • daptomycin
  • linezolid
  • trimethoprim/sulfamethoxazole (TMP-SMZ)
  • quinupristin/dalfopristin
  • clindamycin
  • tigecycline

Squeezing a spider bite isn’t recommended because it can spread the venom. It’s even worse to squeeze an MRSA sore that you think is a spider bite. MRSA wounds can be filled with pus, and it may be tempting to pop or squeeze it but this is not recommended.

A healthcare professional should properly diagnose and treat an MRSA infection. Though this may include draining the sore, it is not something you should try to do at home. I

f your wound starts to ooze or swell, and you’re not sure whether it’s a spider bite or MRSA infection, cover the wound with a dry bandage and contact a healthcare professional as soon as possible.

A wound that grows larger, starts to ooze pus or fluid, or becomes painfully inflamed may be reason enough to consult a healthcare professional.

However, when it comes to bites, wounds, and MRSA infections in particular, the presence of a fever is a big red flag.

If you develop a fever and also have a wound that is looking worse or not healing, visit an urgent care facility or see your healthcare professional as soon as possible.

MRSA infections can spread, leading to deadly blood or bone infections. Even an untreated necrotic spider bite can lead to tissue loss and other complications. Early treatment is vital to managing both types of wounds.

Many MRSA infections of the skin are mistaken for spider bites early on. Wounds that don’t heal — whether they are the result of a spider bite or something else entirely — should be seen by a healthcare professional.

Any wound, including a spider bite, can end up infected with antibiotic-resistant bacteria that can be more dangerous the longer it goes untreated.