What is Brown Recluse Spider Toxicity?
In the United States, brown recluse spiders, also known as Loxosceles reclusa, are mainly found in southern, western, and midwestern regions. They are typically found in dark locations like under rocks, in the bark of dead trees, or in parts of the house like attics, basements, cupboards, and drawers. They can even be found inside boxes or bed sheets.
When a brown recluse spider bites someone, it can lead to local tissue injury known as dermonecrotic arachnidism. There’s also a term for the bodily reactions caused by the spider’s bite – loxoscelism. This syndrome is caused by the venom from the spider entering the body.
What Causes Brown Recluse Spider Toxicity?
In the United States, the venom of the Loxosceles reclusa, also known as the brown recluse spider, is considered the strongest among spiders. It’s also the most likely to cause a skin-condition known as dermonecrotic arachnidism, which involves skin damage and decay.
Risk Factors and Frequency for Brown Recluse Spider Toxicity
While it’s rare, systemic involvement, a condition where the whole body is affected, is more likely to happen in children than in adults. Recently, there has been an increase in reported brown recluse spider bites, even in areas where these spiders are not typically found. However, these cases might be due to other conditions that cause similar looking skin lesions, such as skin infections caused by methicillin-resistant staph aureus.
Signs and Symptoms of Brown Recluse Spider Toxicity
When a brown recluse spider feels threatened or gets crushed, it might bite you, typically if you’re indoors or maybe rolling over it in bed. Some bites look like a hive or a rash. A more serious bite from this spider follows a pattern. Initially, you won’t feel any pain at the site of the bite. However, two to eight hours later, it starts becoming more painful. You might feel generally unwell, nauseous, have a headache, or muscle pain. Children tend to have a more severe reaction – they might experience weakness, fever, joint pain, severe anemia, low platelet count, organ failure, blood clotting disorders, seizures, and even death.
The bite site may have two small puncture wounds surrounded by redness at first. As time goes by, the bite’s center becomes pale while the surrounding area reddens and swells, causing more pain due to the narrowing of blood vessels. Following this, a blister forms over the next few days. The middle of the ulcer then takes on a blue or violet color and becomes hard, with a sunken, star-shaped center. The skin then starts to peel off. Healing then begins, usually taking several weeks.
- Bite becomes painful after 2 to 8 hours
- General feelings of unwellness
- Nausea
- Headache
- Muscle Pain
- In severe cases in children: weakness, fever, joint pain, severe anemia, low platelet count, organ failure, blood clotting disorder, seizures, and even death
- Bite site starts with two small puncture wounds
- Bite site becomes pale in the center, red and swollen around the edges
- Formation of a blister
- Ulcer center changes to a blue/violet color with a hard, star-shaped, sunken center
- Skin in the affected area peels off
- Healing of the wound over several weeks
Testing for Brown Recluse Spider Toxicity
Being bitten by a brown recluse spider is a diagnosis that can only be definitively made under certain conditions. These include if the patient has a wound that looks like a spider bite, the patient saw the spider bite happen, and the spider was caught and identified by an insect expert.
When a doctor suspects a brown recluse spider bite has occurred, lab tests are not typically needed unless the patient (particularly a child) has symptoms affecting the whole body. In such cases, a range of laboratory tests might be undertaken, including a complete blood count and checks for levels of different substances in the blood.
However, bites from various creatures can often be mistaken for brown recluse spider bites, especially if the spider wasn’t caught. A handy memory aid to refer to is the acronym ‘NOT RECLUSE’ which can help rule out a bite from a brown recluse spider. This stands for:
- N – ‘Numerous’: A brown recluse spider usually causes only one lesion.
- O – ‘Occurrence’: These spiders commonly bite when they are disturbed. Despite their names, they tend to stay hidden away in dark places like boxes or attics.
- T – ‘Timing’: Most bites from this spider happen between April and October.
- R – ‘Red center’: Bites from a brown recluse spider usually have a pale center due to damage to the small blood vessels causing low blood supply.
Continuing with the acronym:
- E – ‘Elevated’: Bites are typically flat. If the wound is raised more than 1 cm, it is likely not a brown recluse spider bite.
- C – ‘Chronic’: Bites from this type of spider usually heal within 3 months.
- L – ‘Large’: These bites are rarely larger than 10 cm.
- U – ‘Ulcerates too early’: If the bite is from a brown recluce spider, it won’t become an open sore until 7-14 days have passed.
- S – ‘Swollen’: Bites from these spiders usually don’t cause significant swelling unless they are on the face or feet.
- E – ‘Exudative’: Bites from brown recluse spiders don’t cause oozing wounds.
Treatment Options for Brown Recluse Spider Toxicity
If you’ve suffered a bite or wound, start with basic first aid. The affected area should be raised above the heart or at least in a neutral position. Applying an ice pack to the area can help stop the injury from worsening as the activity of a certain venom component (sphingomyelinase D) is affected by temperature. Clean the wound with soap and water, and make sure the person’s tetanus shot is up-to-date. Over-the-counter anti-inflammatory drugs can help with pain, but in some cases, stronger narcotic pain relief might be needed. Antibiotics are only necessary if there is an infection in the skin.
There is limited proof to support the use of dapsone or antivenom. It’s important to note that dapsone can be harmful to people with a certain type of anemia (G6PD deficiency), and can cause dangerous allergic reactions. Steroids might be helpful because they’ve been shown to reduce the breaking down of red blood cells and help prevent kidney failure. If the infection is serious, hyperbaric oxygen therapy (therapy that involves breathing pure oxygen in a pressurized room) and surgical removal of the wound might be considered once the wound’s edges are clearly defined. It’s not advisable to do surgical cleaning of the wound too early.
Treatment for overall body symptoms differs from treatment for local symptoms; hospital admission is recommended for individuals with serious conditions such as hemolytic anemia, muscle breakdown, blood clotting abnormalities, or organ failure. The treatment for these conditions wouldn’t change in this situation compared to any other cause.
In children, a systemic reaction to a spider bite might happen without skin symptoms and should be considered particularly in children with unexplained acute hemolytic anemia (a condition where red blood cells are destroyed), especially in regions known to have the brown recluse spider. This reaction has been reported up to 7 days after a spider bite. Therefore, parents should be given clear instructions for follow-up care, even if there are no systemic symptoms during the emergency department visit. At the very least, a urine test should be done during the initial visit if the suspected cause is a brown recluse spider bite, and the patient is being sent home.
What else can Brown Recluse Spider Toxicity be?
- Infections on the skin caused by a bacteria called MRSA
- Severe fungal infections that affect deeper layers of the skin
- Skin infections caused by the anthrax bacterium
- A rare skin condition called Pyoderma gangrenosum
- Bites from different types of insects
- Stevens-Johnson syndrome, a severe reaction, usually to medications or infections
- Toxic epidermal necrolysis, a life-threatening skin disorder typically caused by a drug reaction
What to expect with Brown Recluse Spider Toxicity
Bites from the Brown recluse spider usually result simply in local tissue damage. Death is rarely associated with these bites but there have been some cases, particularly in children.
Possible Complications When Diagnosed with Brown Recluse Spider Toxicity
If treatment has been ongoing for 4 to 6 weeks, it might become necessary to move on to a process called delayed skin grafting.
Preventing Brown Recluse Spider Toxicity
Most spider bites are harmless, including those from the brown recluse spider. Bites from these spiders can however lead to serious complications, and have been known to cause fatalities amongst children, albeit rarely.
The brown recluse spider can be identified by a violin-shaped pattern on its body, where the legs are attached. However, it is worth noting that this marking can also be found on other spider species.
You are more likely to be bitten by these spiders during the summer. They usually hide in warm and dark places like attics, garages, tucked inside shoes or corners of beds. Despite this, these spiders are usually not aggressive and will likely only bite when they feel threatened, like if they are squeezed between a surface and your skin.
The venom of the brown recluse spider is highly toxic, although the small amount typically injected during a bite rarely leads to serious damage. This venom does, however, contain an enzyme that can lead to significant damage, like rupture of blood vessels, cell death at the bite site, and even prompts your body to release cells to counteract the venom. These cells can, unfortunately, cause harm, leading to destruction of red blood cells and blood clotting cells (platelets), as well as damage to vital organs, which can potentially lead to kidney injury and coma in severe cases.
The initial bite often goes unnoticed and generally becomes more painful 3 hours after the bite. Indications of a bite to lookout for include redness around the area, fang marks, a white blister, or even a blue discoloration that may form weeks later. Severe symptoms may also include nausea, vomiting, intense itching, and muscle pain.
It is advisable to see a doctor immediately if you suspect a brown recluse spider bite. This would be easier if you could bring in the spider, to be sure of the type. Lab tests are unnecessary if there are only skin symptoms, but your doctor may order tests like a complete blood count, electrolyte panel, coagulation studies, kidney function, and urinalysis if you have general body symptoms like fever, headache, or muscle pain.
Immediately following a bite, before reaching a medical facility, you can take steps to mitigate the damage: clean the bitten area with soap and water, keep it elevated above heart level, apply ice, and take a basic painkiller like acetaminophen. Additional treatments including a tetanus shot, antihistamines for itching, antibiotics if there are signs of infection, and more intense pain medication could be prescribed at the hospital. Note, however, that there is no antivenom for these bites available in the US, and the effectiveness of some additional treatments are still in contention, and could indeed have severe side effects.
Keeping an eye on the progression of symptoms is important. Regular follow-ups with a primary care doctor to determine the extent of skin damage is advisable. If the initial results and symptoms are alarming, hospital admission may be advised for monitoring. In instances where there is skin death (necrosis) from the bite, you may need to consult a surgeon.
