CPR First Aid

How Dangerous Is a Brown Recluse Spider Bite?

The brown recluse is another notable spider to study. Learn more about the bite of a brown recluse spider and if it is dangerous to people.

Another day, another spider steps into the spotlight. With all the possible spider species in Australia, it is common to see new spider species every so often. Apart from the hazardous black widow spider, funnel web, and redback spiders, the brown recluse spider (Loxosceles recluse) is yet another notable arachnid to note. 

Other than learning more about it, we are here to determine whether this spider’s bite is dangerous to humans. 

Let’s dive in and see how dangerous the bite from this spider is. 

Leading Them Out of Reclusion

Before we get to the bite, let’s learn more about this type of spider. This is our opportunity to lead it out of reclusion and bring several characteristics into the light.

Spider profile: unveiling hidden traits before the bite.


It is known for having a uniform colour throughout its body and legs, which is light brown. It also has a violin-shaped marking on its head.


This spider is found throughout much of the southern and central United States. It is most common in the Midwest and southeastern states. While initially not native to Australia, there were recently increased sightings. Eventually, this species became one to be feared in Australia. 

As the name suggests, they prefer to live in the dark, sheltered places such as:

  • In woodpiles
  • Under stones
  • In debris
  • In cluttered storage areas
  • Garages

The hot weather has now driven these spiders into people’s homes. It can also be found indoors in basements, attics, crawl spaces, and closets. Outdoors it is often seen around foundations or under porches.

Primary Attractor

The primary attractor for this spider is insects. It will also eat other spiders and small animals if it can catch them. A brown recluse’s diet primarily consists of crickets, roaches, sowbugs, and mealworms.

It is not a social spider. It does not build webs to trap prey. Instead, it stalks its prey and then grabs it with its front legs. It will also eat dead insects.

Nighttime Creatures

This arachnid is a nocturnal creature and is most active at night. It comes out at night to hunt for food. If it is disturbed, it will quickly retreat to its hiding place.

During the day, it hides in dark places such as under rocks, debris, or similar hiding spots around the house. They use this time for webbing that they use to create egg sacs.

The Bite of the Brown Recluse Spider

Now that we know more about what the recluse looks like, where it lives, and what it eats, let’s get to the spider bite. We want to know whether the bite is life-threatening to humans and what symptoms occur from it.

"Learn recluse spider: habitat, appearance, diet. Explore bite effects on humans."

Is the Bite Dangerous?

The short answer is equal parts yes and no. The recluse is a very venomous spider. Its venom rivals that of rattlesnakes. Fortunately, it can only offload a small amount of spider venom, often not enough to kill a person.

While they are generally not aggressive, they will bite if they feel threatened. It will also bite if it is accidentally crushed or touched. The brown recluse will usually only bite humans if there is contact with the spider itself.

Most times, their bite areas will heal themselves. However, there are some cases where their bite results in severe cases such as skin infections, death of nerves, or tissue damage which all require medical care.

What Happens After a Bite?

The symptoms of a brown recluse spider bite depend on how much venom was injected into the person and how sensitive they are to the venom. In most cases, severe symptoms develop within 2 to 8 hours after the bite occurs.

In some cases, there may be no symptoms at all. In other cases, the following symptoms may occur:

  • Intense pain
  • Nausea
  • Vomiting
  • Fever
  • Body aches
  • Rash
  • Itching
  • Blistering
  • Open sore

As always, people can be allergic to the venom within a spider. This will trigger anaphylaxis which leads to a whole new set of problems.

Brown recluse bite symptoms vary by venom amount & individual sensitivity. Severe signs usually appear 2-8 hrs post-bite.


The venom from this spider contains a protein that can kill tissue and cause necrotic lesions or necrosis (the death of cells). This can lead to the development of a lesion at the bite site. The lesion will start as a small red bump that gradually grows.

Sometimes, the lesion can become as large as 10 cm in diameter. Lesions usually take 2 to 3 weeks to heal. If left unchecked, the necrosis can spread which will require medical attention. A healthcare professional will need to remove and repair these dead tissues. In some cases, skin grafts may become necessary.

In severe but rare cases, the venom from the recluse can cause certain medical conditions such as:

  • Kidney failure
  • Liver damage
  • Muscle damage
  • Gangrene
  • Coma
  • Systemic Loxoscelism (destruction of red blood cells)
  • Death

Treatment for a Recluse Bite

If you believe a brown recluse has bitten you, you must seek medical treatment immediately. Try to capture the spider so the doctor can use it to determine the best course of treatment.

After being bitten, clean the wound with soap and water. Apply an ice pack to the area to reduce swelling. 

Do not attempt to remove the venom yourself. It can cause more damage. Venom removal kits are also not effective.

Your doctor’s medical advice may include giving you a tetanus booster if you have not had one in the past five years. If the bite is more severe, you may need to be sent to an emergency room. You may receive antivenom, over-the-counter pain relievers (like NSAIDs), antihistamines, IV fluids, and more.

Prevention is the Best Medicine

The best way to avoid insect bites and stings is to take precautions to avoid contact with them.

First, inspect your clothing for spiders before getting dressed. Wear long-sleeved shirts and long pants if you know there are certain spiders in an area. Tuck your shirt into your pants and your pants into your socks, and wear gloves.

In addition, make sure to shake out all clothing, towels, and bedding before use.

If you believe there is an infestation in your home, contact a professional pest control company. Do not attempt to remove them yourself, as this can be dangerous.

Caution and Vigilance

While not immediately fatal, the bite from a brown recluse spider is capable of imbuing necrosis which kills tissues and cells. The complications introduced could lead to life-long conditions and even death if left unchecked. 

Caution and vigilance are the best elixirs towards any spider, including this one. If you add the right first aid skills and knowledge, dangerous spiders can be easily handled. Not only will it help you with handling spider bites, but it will also come in handy for many other medical emergencies. 

Visiting the health library of government websites that discuss spiders and their bites may also help.

Learn more about first aid with CPR First Aid’s Liverpool course today.



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