Even though most of us are certain we’ve had dozens of spider bites, the truth is that they are quite uncommon. Generally other insect bites, like mosquitoes or bed bugs, are attributed to spiders despite the fact that there aren’t many spiders with strong enough fangs to pierce human skin. Even fewer spiders have the venom to cause skin irritation if they can pierce the skin.

The two spiders that should most concern you are black widow and brown recluse spiders as they can pierce the skin and cause spider bite symptoms. Even these spiders rarely bite unless they feel threatened.

Look at photos of a black widow and a brown recluse spider. If you see them around your home note it for future bites.

black-widow
Black Widow Spider
brown-recluse
Brown Recluse Spider

Despite this fact it is important to be able to identify these spiders and recognize the symptoms of spider bites to properly treat them.

Spider Bite Symptoms

Most spider bites present with a variety of similar symptoms, which can make it difficult to know if you have a spider bite or other insect bite. However you should be aware of general and specific symptoms of spider bites for fast and effective treatment.

Traditional spider bite signs and symptoms include:

  • Redness at the area of the bite
  • Irritation
  • Pain
  • Itching
  • Swelling

Black Widow Spider Bite Symptoms

Because black widow spiders are quite small many people don’t realize they have been bitten at all until symptoms appear. However the pinprick feeling upon the initial bite is a key symptom of black widow spider bites. The symptoms will vary based on how much venom was released and your sensitivity to the venom. Some symptoms you may experience include:

  • Swelling around the bite area
  • Cramping in abdominal region
  • Numbing pain radiating from the bite site to back and abdomen
  • Stinging sensation at bite mark
  • Nausea
  • Vomiting
  • Dizziness
  • Tremors
  • Elevated blood pressure
  • Muscle and joint pain
  • Rash
  • Facial swelling

Keep in mind that if you have allergies these symptoms may be exaggerated, particularly the swelling, nausea and dizziness.

Brown Recluse Spider Bite Symptoms

Getting bitten by a brown recluse spider is a fairly harmless feeling as the bite itself is quite painless. But the symptoms of brown recluse spider bites are what you should keep an eye out for as they surface within 8 hours of getting bitten. In addition to mild tissue destruction, other symptoms you will experience after a brown recluse spider bite are:

  • Muscle pain
  • Fever
  • Nausea & vomiting
  • Persistent itching
  • Pain at the site of the bite
  • Blistering
  • Redness
  • Fang marks
  • Blue skin discoloration
  • Dead subcutaneous fat

Sometimes these symptoms can become quite severe leading to necrotic lesions and severe scarring.

Are Spider Bites Dangerous?

Some spider bites can be very dangerous, especially if you have allergies to something contained within the venom or the spider. However most spider bites are not dangerous whatsoever because the majority of spiders are not strong enough to pierce your skin and they don’t produce enough venom to cause a reaction. In fact the great majority of spiders are harmless with the exception of spiders like black widows and brown recluses.

Bites from black widow and brown recluse spiders cause visible symptoms but they may also require medical care if the symptoms worsen. Because most people don’t feel the bite when it happens, it can be hours or days before symptoms are noticed, which increases the chances of complications from these spider bites.

What Does A Spider Bite Look Like?

Spider Bite
Spider Bite (Photo credit: Doug Sparks)
English: Spotted willow spider bite
English: Spotted willow spider bite (Photo credit: Wikipedia)
Spider Bite
Spider Bite (Photo credit: Doug Sparks)
English: 4 mo. after a brown recluse spider bi...
English: 4 mo. after a brown recluse spider bite, scaring remains (Photo credit: Wikipedia)

The most common physical attributes of a spider bite are redness and swelling around the bite area. Some spider bites will also have signs of the fang marks at the site of the bite. In general the spider bite has just the aforementioned visible symptoms in addition the many physical symptoms.

What To Do If You Are Bitten By A Spider?

If you are certain that you have been bitten by a spider you should take care of it immediately. Some symptoms take a few hours to appear but should still be treated immediately. The first two steps you should take after receiving a spider bite are to clean the bite site thoroughly with antibacterial soap and warm water and then apply a cold compress to the same site. The cold can be a towel or ice pack.

You can use over the counter medications to help you treat spider bite symptoms such as itching, swelling, redness or pain.

If you have been bitten by a brown recluse spider or black widow spider you should follow the same treatment plan as above but you will also need to elevate any extremities that have received bites. Some other spider bite treatments include:

  • Stop the spread of the venom by lying still for at least an hour
  • Call local poison control
  • Get anti-venom medication
  • Get a tetanus booster shot if your immunization isn’t up to date.

Preparing For Your Appointment

If you think you’ve been bitten by a spider, particularly a brown recluse or black widow you should call your health care provider right away or go to a hospital, depending on the severity of your symptoms. Make sure the bite is clean and dry before you leave, and if possible email a photo of the bite and the spider to your physician.

What you can do

To help your doctor diagnose your spider bite you should provide as much information as possible. Write down any symptoms you have been experiencing, when the symptoms first occurred and then they worsen.

If you cannot bring the spider with you, take a photo of the spider that bit you so your doctor can treat you effectively. Many spiders of different species look similar and a photo can help you get the right treatment for your bite.

Finally you should write down a list of questions you need answered by the physician. This list will help you guarantee that you get all your questions answered during a short visit. Some basic questions you might want to ask include:

  1. If this is a dangerous spider bite, what’s the next best step?
  2. If this isn’t a spider bite, what are possible causes for my symptoms or condition?
  3. Do I need any tests?
  4. How long will my symptoms last?
  5. What is the best course of action?
  6. I have these other health conditions. How will that affect my condition now?
  7. Are there any restrictions that I need to follow?
  8. Should I see a specialist? What will that cost, and will my insurance cover seeing a specialist?
  9. Is there a generic alternative to the medicine you’re prescribing me?

Tests And Diagnosis

Accurately diagnosing a spider bite can be very difficult, especially without access to the offending spider. In fact diagnosing the bite as belonging to a spider is difficult as well unless you have the spider or a photo of the spider that bit you. There are really only 3 ways to confirm a spider bite:

  1. Exclusion of other causes of symptoms
  2. Spider identification by expert
  3. Witness or video of bite

This is why it is so important to know what the spider bites look like and what environments they favor.

Treatment

Primary treatment for all spider bites: Treating spider bites is fairly simple if there are no complications. The basic treatment for spider bites include cleaning the bite and working to reduce inflammation through anti-inflammatory medication and cold packs. Elevate the bite area and keep a close eye on it to prevent any infections from occurring. Use over the counter medications for swelling, pain and itching.

Treatment for black widow spider bites: Some populations may require hospitalization to get treated for a black widow spider bite. Young children under 16 and adults over 60 are two populations in which black widow spider bites can become dangerous.

If you have high blood pressure you should also seek immediate treatment at the hospital to insure the bite does not cause your blood pressure to rise. If your symptoms immediately become severe and impact your entire body, you should go to the hospital as soon as possible.

If your symptoms are severe but not enough to require hospitalization your physician may require use of an anti-venom medication which works for as long as 36 hours after the bite. Some people are allergic to anti-venom medications, let your doctor know if you are one of those people.

Treatment for brown recluse spider bites:

After you have completed basic treatments for a spider bite you will have to lie still immediately afterwards if you were bitten by a brown recluse spiders. Brown recluse spider venom can spread quickly in the skin, particularly if you participate in any strenuous activity. Lying down will help prevent the spread of the venom.

To relieve the pain associated with brown recluse spider bites, take an acetaminophen product such as Tylenol.

Avoid “quick fix” treatments such as direct heat, a tourniquet and electricity. Do not attempt to suction out the venom or cut it out as this is virtually impossible and dangerous without a trained medical professional.

Complications

It is highly uncommon for black widow or brown recluse spider bites to lead to serious health complications. If the bite and symptoms are left untreated for an extended period of time—particularly in high risk populations—kidney failure, death and coma are serious possibilities.

Those most at risk for spider bite complications include:

  • Individuals with heart conditions or at risk for heart conditions
  • Infants and children under 13 years of age
  • Adults over 60 years old (particularly those with diagnosed heart conditions)

Brown recluse spider bites can lead to necrosis within the first 96 hours if left untreated. Dead skin (necrosis) and necrotic lesions may require surgery to get rid of dead skin.

Prevention

The best thing you can to do prevent spider bites is to know what types of environments they favor so you can avoid those areas or protect yourself properly. When in cold dark places like basements or attics, wear long sleeves, boots, pants and gloves. Other things you can to do prevent spider bites are:

  • Use bug repellant on clothes, skin and footwear
  • Shake out and wash clothing and shoes that have been stored in crawl spaces, attics or basements
  • Keep storage areas clean and uncluttered
  • Don’t store firewood up against your home or walls
  • Vacuum corners and crevices to get rid of spiders
  • Seal screens on your doors and windows to prohibit spider entry into your home
  • Seal holes and cracks in walls, especially external walls, using caulk or other sealants.

Be very careful in areas that attract spiders and you can avoid spider bites.

Written By Kayla Harris

Dr. Harris is a dermatologist certified by the American Boards of Dermatology and Pediatrics. She has also received a certification in the sub-specialty of Pediatric Dermatology. Dr. Harris received an undergraduate degree biology from the University of Rhode Island. Dr. Harris earned her Medical Degree at the University Missouri. Dr. Harris completed her pediatric residency at the Children’s Hospital at the University of Colorado where she also completed her residency in dermatology just one year later.