Spider Bite Pictures and Treatments

These spider bite pictures can help you determine if a wound could have been caused by a specific type of spider. Photos can help you identify a spider bite, which may look similar to other insect bites or can resemble different types of skin rashes or lesions.

A serious bite from the black widow or brown recluse spider can cause severe skin changes and other problems. The effects of non-serious bites, which are more common, lead to minor symptoms.

While reviewing typical reactions to spider bites, it's important to also understand signs that something is not a spider bite.

What Does a Spider Bite Look Like?

Spider venom acts differently in humans than bites from a mosquito or flea or a sting from a hornet or bee. Even so, there may be some overlap in symptoms.

The following are some of the tell-tale signs and symptoms of a spider bite:

A Bullseye Rash

Bullseye rashes are most common in tick bites that cause Lyme disease, but a different type of bullseye can be caused by spiders.

The bite of a brown recluse may develop a bullseye—known as erythema migrans. At the center, there may appear a white blister surrounded by a red ring. The ring can turn purple or blue with time.

This photo contains content that some people may find graphic or disturbing.

See Photo

Fang Marks

Depending on the size and type of the spider that bites you, you may be able to see actual fang marks. These typically present with two small, side-by-side holes in your skin.

Fang marks are sometimes seen with female black widow bites or male and female brown recluse spiders, which have hollow fangs (chelicerae). Venom is injected into your bloodstream through these fangs.

This photo contains content that some people may find graphic or disturbing.

See Photo

Tissue Death

Brown recluse spider bites can cause painful, purplish blisters that break open into ulcers. The ulcer forms as a result of the spider's venom, which is necrotic, meaning that it kills tissues. Necrosis occurs because the venom kills small vessels, called capillaries, that provide blood to surrounding tissues.

This photo contains content that some people may find graphic or disturbing.

See Photo

An Expanding Lesion

There are many different things that can cause a lesion to expand or spread. Though an expanding lesion is common in some spider bites (including a brown recluse spider bite), it can also occur with certain skin infections like impetigo.

If you're unsure whether a lesion is growing, draw a line around it and monitor for any changes over the coming hours. Record the time so that you can report back to your healthcare provider if, in fact, the lesion is spreading.

Symptoms of a Dangerous Spider Bite

Only two spiders in the United States are known to be extremely venomous to humans: the black widow spider and the brown recluse spider.

However, in rare instances, you may have an allergic reaction to another common spider, the wolf spider.

Brown Recluse Spider Bites

A brown recluse spider is recognized by its dark brown color and violin-shaped body. Its bite may look initially look like a flat area of whiteness (caused by the death of local capillaries and loss of blood flow). It will eventually turn black and blue as blood leaks from the disrupted blood vessels.

After a week a brown recluse spider bite may look worse as the skin forms a purplish or blackish blister. The blister will then erupt into a painful, open sore (ulcer).

Necrosis can appear either as dry, thick, leathery tissue or as yellow, green, or brownish tissues that are moist, loose, and stringy. When the ulcer heals, it can leave behind an ugly scar.

Other whole-body symptoms of a brown recluse spider bite include:

• Headache
• Fever
• Muscle aches
• Joint pain
• Nausea
• Tiredness

Brown recluse spider bites rarely kill people, but it's important to get medical attention as soon as you can because a bite can make you very ill.

Black Widow Spider Bites

Black widow spiders are typically black with two reddish triangular markings on the underside of the hourglass-shaped body.

Its bite may look less obvious than a brown recluse spider bite. You may feel a pinprick sensation and see two fang marks accompanied by local redness and swelling.

Black widow venom works quickly, often within an hour, and may cause severe whole-body symptoms like:

• Fever with chills
• Headache
• Nausea or vomiting
• Severe muscle cramping
• Profuse sweating
• Severe chest, back, or abdomen pain

A black widow spider bite is unlikely to kill you but can make you seriously ill and may even require hospitalization.

Wolf Spider Bites

Wolf spiders, sometimes mistaken for brown recluse spiders, are recognized by their hairy bodies and multiple eyes (two medium eyes on the top, two large eyes in the middle, and four smaller eyes on the bottom).

Wolf spider bites are usually harmless. However, if you are allergic, you may develop the following symptoms:

• Rapid heart rate
• Difficulty breathing
• Trouble swallowing
• Chest tightness
• Mouth or face swelling

Contact your healthcare provider if you experience any of these reactions.

Harmless Spider Bites

A variety of spiders are likely to bite if you disturb them. These bites are usually not serious. The American house spider and common arachnids found in nature, such as the following, are not dangerous.

• Flatties
• Flower crab spider
• Garden orb weaver
• Crab spider
• Green lynx spider
• Jumping spider
• Spotted orb weaver spider
• Tarantula
• Harvestmen spider
• Camel spiders
  

A bite from one of these spiders may only cause mild redness, swelling, and pain. However, even minor spider bites can become infected if you scratch or pick at them.

If you notice increased redness, swelling, or pus, see a healthcare provider to check for an infection.

When to Call a Healthcare Provider

While not many insect bites will require immediate medical attention, there are some situations where you should always seek care:

• You believe that you've been bitten by a venomous insect, like a black widow spider.
• You develop a bullseye rash (which could be a sign of Lyme disease).
• A skin lesion continues to get worse over a 24-hour period.
• You have whole-body symptoms such as fevers, chills, aches, and nausea.

If these symptoms are not involved, it's probably fine to keep the lesion clean and watch for any changes.

How Spider Bites Are Treated

In most cases, a spider bite can be treated at home.

To care for your wound:

• Wash the area with soap and water.
• Apply a topical antibiotic to prevent infection.
• To reduce swelling and ease pain, place a cool compress on the wound (apply for no more than 15 minutes at a time).
• If you are bitten on an arm or leg, elevate the wound.
• If you have pain and swelling you can take an over-the-counter nonsteroidal anti-inflammatory drug (NSAID), such as Advil (ibuprofen).

Any bite that worsens or becomes infected should be seen by a healthcare provider.

If your bite is caused by a black widow, your healthcare provider may treat it with muscle relaxants or stronger opioid painkillers. In severe cases, an antivenom can be given, but this is usually a last resort as it may cause anaphylaxis.

If a brown recluse bite grows in size and becomes painful, your healthcare provider may prescribe antibiotics to prevent infection. If it is unclear that you've been bitten by a brown recluse, a tetanus shot may be given as a precaution, particularly if you haven't had one in the past five years.

Summary

Most spider bites are harmless. The exceptions in the United States are bites from the brown recluse spider (which can cause a painful skin ulcer and tissue death) and a black widow spider (which can cause severe, whole-body symptoms). Even so, deaths from a brown recluse and black widow spider bite are rare.

Knowing the signs and symptoms of a venomous spider bite can help you make an informed choice as to whether emergency medical care is needed or not. If in doubt, call or see your healthcare provider.