What is the appropriate treatment for a spider bite?

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Spiders use four attack modalities: Dry Biting (no envenomation), Irritant (the "hairs" create an irritation) - seen only in tarantulas, neurotoxic envenomation and necrotoxic envenomation. So you can get hurt in quite a few ways:

Dry Bites

Dry bites hurt, but they're only holes in the skin with little swelling. Treat these with a cold pack and a mild painkiller. They should disappear in 3-5 days or less. If not, read down to the section on Infections.

Most spider bites fall into this category.

Irritation

This is the New World Tarantula's main attack modality. If you handle or irritate them they may fling sharp hairs from their thorax at you and a rash may possibly develop. The effect is very mild and mostly is a local irritant. Really not a lot to treat.

Neurotoxic Envenomation:

This is the modality used by genus Latrodectus-- the Widow Spiders, which includes the black widow. Black widows use proteinic neurotoxins that attack the nerve cells, and transmit through the lymphatic system. Two sets of effects can occur resulting from an envenomating bite (note that Widow Spiders often "dry bite"). A red bump forms almost instantly, and can be extremely painful. Treatment for this is pretty much the same for all spiders: Cold pack the wound and administer a mild to moderate painkiller.

Experimental Treatment

Not discussed in any of the books is a method borrow from the Marine Biologist's take on proteinic toxin envenomation. Proteins don't hang together well when exposed to heat. In the case of jellyfish stings, one first aid treatment is to hot pack the wound with hot, wet compresses -- hot as the patient can stand without getting burned for about 5-10 minutes. This may denature the toxins much in the way egg whites turn white and hard in hot water.

Note that this method is not discussed in the literature for Arachnidae that I could find, but I can't think of a way it could do any significant harm, for the bite described above. A major systemic neurotoxic reaction however is likely to not benefit from this method -- see below.

In more rare and more serious cases, neurotoxins can go systemic (i.e. throughout the system). Symptoms include:

• Intense pain
• Muscle cramping/rigidity
• Rigid stomach (occasionally misdiagnosed as an acute abdomen) -- this is the signature symptom.
• Priapism
• Sweating, most commonly at or around the site of the envenomation
• Cardiac Arrhythmias (bradycardia, tachycardia).
• Panic and fear of dying

While rarely fatal, any of these symptoms call for hospitalization and a 911 call. At the hospital, the medical team have the option of administering an antivenin, but probably won't as all these symptoms can be addressed by more conventional means, and are less likely to invoke an allergic reaction. They may also administer calcium gluconate. Relief should be quite fast.

If you can't transport and must treat in the field, administer muscle relaxants (as prescribed by a doctor, if you have them), antihistamines (in case of anaphylacsis per instructions on the box -- maximum dosage recommended) and pain meds. Watch for cardiac trouble. Elevate the wound if it's on an extremity to reduce swelling. Minimize patient activity unless you can get to a hospital fast, in order to minimize spread of the toxins. If left untreated, these symptoms may last 3-5 days.

The injection site should heal in a few days, leaving no sign.

Necrotoxic Envenomation:

This is the realm of the Brown Recluse spider, of genus Loxosceles. Note that most "Brown Recluse bites" aren't really Brown Recluse bites. Many spiders look a lot like a Brown Recluse, even including the violin shaped mark, but still aren't. Some may dry bite, or deliver small amounts of necrotoxin, and this may cause a false guess about what bit you. The best means of identification is to trap the spider and bring it with you to an expert. As this isn't always possible or practical, one can distinguish the real Brown Recluse from most of its look-a-likes by the arrangement of the eyes. While most similar spiders have two columns of 4 eyes each, for a total of eight eyes, the real Brown Recluse has 3 pairs (dyads) of eyes arranged sort horizontally, like headlights, with the middle ones slightly higher than the sides.

Four levels of bites can occur:

· Unremarkable (requiring no care at all)

· Localized (healing on their own but with a little help)

· Dermonecrotic (where the necrotoxin kills tissue cell, which will require serious treatment)

· Systemic (in which the toxins actually attack organs in the body, and life support measures may be required).

For any of these, the initial symptoms include:

· Bruising

· Redness

· Itching (Don't Scratch!)

· Pain.

· *** Note - these are exactly the same symptoms that appear with almost any arthropod bite, including insects and spiders as well. Some or all of these may occur - or not.

Within 10 minutes of the bite, the center of the bite may start to bruise. Around this is a whitish ring, which is in turn surrounded by a reddish ring - the characteristic "target" shape that appears if you've been stung by a an animal that uses necrotoxins. Note that many spiders may use similar toxins in doses well below that of the recluse, so this sign is not unique to Brown Recluse spiders.

However, if the bite turns dark blue/purple over the next two hours or so, this is an indication of the onset necrosis (so this wound will require some attention at least, and likely won't heal on its own). If this occurs, part of the dermis may die from lack of circulation, forming a blister, which in turn will scab over, in the course of 7-14 days. At the end of this time, the scab should fall off, and reveal an ulcer, which will need to be treated. At this time, auto-immune factors may spread from the bite site. If this happens, you need to get this worked up in a hospital.

Let's go over the timetable again:

· Symptoms start in 10 minutes, possibly forming a "target" or "bull's-eye" pattern.

· If the wound is not self healing, other symptoms should start in 2-6 hours.

· You should know from the symptoms if the wound is going to become necrotic in 12-24 hours.

· In 48-96 hours, if nothing happens, you should be in the clear.

Note that treatment works best within the first 24 hours. If you take this to the hospital in that time, your odds of a successful treatment increase significantly. Conversely, waiting longer increases the danger of significant necrosis.

Systemic Reaction to Necrotoxins

If the venom goes systemic and attacks much of the body, it will usually start within 2-3 hours and it may not display the earlier describes symptoms! Instead, look for blood in the urine, which may or may not be present. Look also for fever, nausea or vomiting. NOTE that systemic reactions cause a lot of problems in terms of blood chemistry, but you won't have equipment at home to see these.

See the Poison Control information near the end of this article for good advice. You can also call your hospital and ask if you need to come in. Some of the problems with identifying systemic reactions to Brown Recluse spiders are that the symptoms are not clearly indicative of a problem, and the hospital testing is somewhat expensive. This is a decision you'll have to make for yourself. This condition is rare, but it's tough to treat when it happens, and the longer you wait the more difficult it becomes.

NOTE - children and the elderly are more susceptible than adults due to their smaller body mass and co-morbid medical problems, respectively.

Infection:

Most spider stings, at some point in their evolution, itch. If you scratch them, they can create small, open wounds. Some spider stings create open ulcers as well. Either way, you need to disinfect any wounds like these that become infected.

If it's simply a healing spider bite and nothing worse, wash with soap and warm water, and hit it with Betadine or hydrogen peroxide, and band-aid it.

If the wound ulcerates seriously, get your doctor to advise you on antiseptic procedures. In these more serious cases always let your health care professional know if you suspect infection. You'll look for:

· Pus

· The wound feeling hot

· The size of the wound getting larger

· Bad smells from the wound

Allergies:

Any injection type sting can set off an allergic reaction. With minor cases, you'll feel itching at the wound site (which you might feel anyway). Diphenhydramine is the fix for this. It's available over the counter in cream and tablet form. Take according to the directions on the label. Note that if you use both the cream and the tablets, your dosage increases - make sure not to exceed safe dosages.

Try and avoid steroid creams if you have open wounds and especially infections. Steroid creams may help if the hives and wounds are closed.

If you have any of the following reactions, call 911:

· Shortness of breath or difficulty breathing

· Sudden appearance of hives and welts (not counting the original sting location).

· Wheezing

· Nausea or vomiting

· Loss of consciousness

Note that severe reactions like this are rare.

Two common American spiders can inflict serious bites- the small brown (recluse) spider and the black widow. The latter is a coal-black spider with a pea-size abdomen marked with a reddish hourglass design.

The black widow's bite causes intense pain, muscle spasm, weak pulse. The pain moves gradually from the wound and concentrates in the abdomen. The brown spider's bite may not be immediately painful but, if not treated, tissue breaks down in the area of the wound.

Get to a doctor immediately. Save spider for identification, if possible. Meantime, wash wound with soapsuds and apply baking soda compress, give black coffee as stimulant, watch for signs of shock.

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I'm going to suggest holding off on the coffee if you're going to transport. See DISCUSSION for this.

First answer by ID1281992572. Last edit by Cjonb. Contributor trust: 200 [recommend contributor]. Question popularity: 21 [recommend question]