What to do if you have a spider bite

Some spider bites can make you sick. Here's what you need to know.

spider on skin

If you get spooked by spiders like we do, remember this: Most spiders are harmless – and in fact, they're necessary for the environment. “Spiders are very much a part of our ecosystem," says emergency medical director Jon Pangia, DO of Grand Strand Medical Center in Myrtle Beach, South Carolina. "They're killing some of the other bugs, and they're keeping your yard cleaner than you ever could." What's more, he adds, "Hardly any of them ever would even come close to biting you." We talked with Dr. Pangia for the 411 on spider bites, what symptoms they cause, and how to treat and prevent them.

Recognizing a spider bite

Unless you actually see the spider bite you, which is rare, you probably won't notice the bite until after the fact, says Pangia. In most cases, it will look similar to a mosquito bite, creating a red, itchy, swollen spot that usually goes away on its own.  

In the U.S., bites from two types of venomous spiders, the black widow and the brown recluse, can cause serious reactions. Watch for these signs:  

Black widow:

  • Pain in chest or belly
  • Swelling, redness or target-shaped rash around the bite
  • Anxiety
  • Trouble breathing
  • Cramps
  • Headaches
  • Nausea
  • Sweating
  • Rapid heartbeat

Brown recluse:

  • Blister or ulcer at the bite spot
  • Intense pain, like a bee sting
  • Itching
  • Chills
  • Sweating
  • Nausea
  • Purple coloring around bite area

Treatment

For minor spider bites:

  • Wash the area with soap and water.
  • Place ice or an icepack over the area for 10 minutes at a time to relieve stinging and reduce swelling.
  • Take over-the-counter pain medication if needed. 

 “If it’s a small little bite that’s not getting bigger, you can just leave it be, and it will probably go away,” says Pangia.

For severe symptoms:

  • Go to the emergency room if your symptoms become worse, or if you know you were bitten by a black widow or brown recluse. Even if the bite isn't poisonous, you could be having an allergic reaction, which can lead to swelling around the face and mouth, difficulty breathing and trouble swallowing. Watch especially for severe symptoms in small children and the elderly, whose immune symptoms may be weaker.
  • If you’re unsure what type of bite it is or whether it requires a trip to the doctor, call 911 or Poison Control at 1-800-222-1222 right away and they can provide instructions.

Prevention

The first step towards prevention is learning what venomous spiders look like and of course, where they typically live. If you live in the woods, you know that it’s impossible to keep spiders out of your yard. But you can take measures to keep them from getting in your home, and you can protect yourself while you are outdoors. Wear long-sleeved shirts and pants when spending time outside or in garages or sheds. And make sure to always shake out work gloves and boots. To keep spiders out of your home, stop up any open drafts and keep doors and windows shut tight. “They can get into the tiniest of holes,” says Pangia. Pay special attention during the fall months, he adds. “They're trying to find a warm place to spend the winter, so that's when you really have to be extra vigilant."

See More from Dr. Pangia:

What information should I give in the emergency room? 
How long is the average patient emergency room wait?
What information should I gather if I think someone has swallowed a poison?

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