Spider Bites Vs. Bed Bug Bites: What’s the Difference?

You wake up with weird bites on your legs. You know it’s wasn’t fleas or mosquitoes that bit you. What was it, then? Could it be a spider bite? Or maybe you have bed bugs.

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It’s not always easy to tell the difference between a spider bite and a bug bite. Both are similar in appearance, and they aren’t quite as itchy as a flea or mosquito bite.

We’re going to take a closer look at these bites, so you can tell the difference between the two.

Spider Bites vs Bug Bites: What’s the Difference?

The appearance, location and symptoms will help you tell the difference between bed bug and spider bites.

1. Main Differences Between Spider and Bed Bug Bites

Spiser isolated on human's skin.
Source: http://health.usnews.com/

Spider bites can be downright dangerous, whereas bed bug bites are more of a nuisance than a risk to your health (unless you’re allergic).

The two bites have different appearances as well.

  • With spider bites, you’ll see a single swollen bite. Black widow spider bites leave fang marks.
  • With bed bugs, you’ll see multiple but small welts on your skin.

Depending on the spider, the bite’s appearance can be frightening. In some cases, a spider’s bite can cause necrosis of the skin. These bites can be difficult to look at and require immediate medical attention.

Bed bug bites occur at night, as these creatures prefer feeding on sleeping hosts. They normally bite exposed parts of the body because they’re the easiest to reach.

2. Bite Locations

The locations of the bites is also a telltale sign of which creature bit you.

  • Bed bug bites appear in clusters and in a linear pattern on the arms, neck, torso and back.
  • Spider bites normally appear on the legs, arms and fingers.

Keep in mind that these are the most common bite locations, and bites can appear in other places. If you have a cluster of bites on your leg, that doesn’t necessarily mean that a spider bit you or that it wasn’t bed bugs.

3. Signs and Symptoms

Bed bug bites on human.
Source: http://nohomebugs.com/

Along with differences in bite locations, there are also differences in the signs and symptoms caused by each creature.

Symptoms of bed bug bites include:

  • Flat or raised clusters of red, itchy bites
  • Red swollen welts near the bite
  • Itchy, painful, pus-filled blisters

Symptoms of spider bites include:

  • Pain at the site of the bite
  • Systemic toxicity, known as Arachnidism
  • Abdominal cramps
  • Paralysis
  • Sweating
  • High blood pressure

Some spiders have potent bites that cause gastrointestinal issues, like cramping and vomiting. Bed bug bites are just itchy.


Close up of a injection on white background.
Source: http://www.thehorse.com/

Bed bug bites don’t typically require any treatment. But an over-the-counter hydrocortisone cream, herbal lotions and antihistamines can be used to help aid in the healing process. It’s also a good idea to wash the bite with mild soap and warm water to prevent infection.

Spider bites, on the other hand, may require treatment. Depending on the spider, an anti venom injection may be required. Increasing pain or swelling may require antibiotics.

A hot washcloth can help ease the swelling while promoting circulation to the bite.


Preventing spider and bed bug bites can be a challenge. Most people unknowingly bring bed bugs into their home and don’t even know they’re there until they have an infestation on their hands.

Spiders are almost impossible to keep out of the home, and there’s no way to keep them from biting you.

The best you can do is take action immediately if you do get bit by either creature. Seek medical attention immediately if you experience spider bite symptoms, and take steps to tackle a bed bug infestation if you wake up with a cluster of bites.

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