How to identify and treat a spider bite

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Identifying and treating a non-venomous spider bite (and when to seek medical attention!)

Most spider bites are harmless but sometimes it can be difficult to tell exactly what it was that bit you because sometimes the bite doesn’t appear until a few hours later and the culprit is long gone.

Telltale signs of a spider bite include:

  • A red mark, a patch or welt
  • Some localized swelling
  • Soreness or itching or a rash
  • Pain around the bite site
  • A red blister
spider bite picture

Picture: a typical spider bite

How to treat a spider bite at home

Treating non-venomous spider bites at home is perfectly possible and advisable as spider bites take a longer time to heal compared to some other insect bites.

  1. Clean the area first with soap and water
  2. Apply an icepack for ten minutes at a time with a ten-minute break after each application to reduce discomfort and any swelling.
  3. Oral over the counter antihistamines can help with itching and inflammatory reactions as it is important not to scratch the bite; this will make itching worse and could cause an infection.

treating a spider bite with an ice pack

Picture: treating a spider bite with an ice pack

When to get help

It may be necessary to seek medical attention for antibiotics, anti-venom treatments, corticosteroids, and even hospital treatment if you know or suspect you have been bitten by one of these spiders:

  • Brown Recluse- sometimes also called the Violin spider because of the dark marking on its back, the Brown Recluse is about an inch in length and brown in color. It is non-aggressive as its name denotes and will only bite if it becomes trapped against human skin.  Typically the bite itself is painless but within a day, the site will start to turn red and itch.  A hallmark red or purple ring that looks like a bull’s eye will develop around the bite.  The bite can blister and continue to worsen to the point where it will cause fever and headache and on very rare occasions, other complications like seizures and jaundice
brown recluse spider

BROWN RECLUSE (VIOLIN SPIDER) Loxosceles reclusa (Image source:

  • Black Widow – easy to identify, the Black Widow has a very distinctive red hourglass emblem on its back and a shiny black body. The Black Widow is another spider who likes to hide away in dark corners.  Only the female bite is toxic and the bite itself will feel like a tiny pinprick if that; some people report that they don’t even remember being bitten.  But there will be clear and distinct evidence of two puncture marks on the skin and this is often accompanied by pain and a burning sensation at the bite site.  Other symptoms include headache, increased blood pressure, sweating, nausea, and vomiting
black widow spider

Latrodectus – Black Widow Spider (Image source: Wikipedia)

  • Hobo Spider – Hobo spiders are easy to spot as they sit up high on long legs and run really fast if you discover their hiding place. They do attack if provoked or disturbed.  They are a household spider and can be found in closets and behind furniture.  The bite is initially unremarkable but it will quickly turn red and within eight hours it will swell and become hard.  After a day, the site will start to discharge and may turn black.  Some bites develop a red or purple blister at the puncture site and other symptoms include general weakness and fatigue, headache, sweating, and nausea
hobo spider

Hobo Spider (Image source: Livescience)

  • Tarantulas – tarantulas are very easy to identify, they are a large spider, anything between 3-5 inches long with hairy red/brown bodies and fangs which are quite visible. Despite their reputation, tarantulas are not an aggressive species and the venom from their bite is not considered dangerous.  The bite will feel rather like a bee sting and the site will become warm to the touch and red.   A rash may develop and there might be swelling and itching at the site.  Other symptoms include a raised heart rate, puffy eyes, and low blood pressure 
brown tarantula

Texas Brown Tarantula (Image Source:

  • Brazilian Wandering Spider – highly dangerous, the Brazilian wandering spider is considered one of the most deadly spiders in the world. It is native to Central and South America.  It is sizeable – up to five inches in length – with a small brown body covered in short bristles and long legs.  The bite itself is extremely painful and will quickly redden and swell.  Labored breathing and drooling usually follow pretty quickly after the bite.  The bite from a Brazilian Wandering Spider is a medical emergency and there is anti-venom treatment available
Phoneutria - brazilian wandering spider

Phoneutria – Brazilian Wandering Spider (Image source: Wikipedia)

Find out which of these spiders are common in your geographical area as it will make it easier to identify the culprit if you are bitten and didn’t see the offending spider.  These bites all respond better to treatment if it is sought quickly, within the first 24 hours after the bite has occurred but preferably immediately.

It is possible to develop a severe allergic reaction to any spider bite and so even if the spider is not known to have venomous tendencies, you should always seek medical help if you experience one or more of the following symptoms:

  • Joint weakness or pain
  • Fatigue
  • Fever or chills
  • Sickness and nausea
  • Confusion or disorientation
  • Elevated blood pressure
  • Rapid or labored breathing
    serious spider bites

    Image source: Medically Significant Spider Bites: Keys to Diagnosis and Treatment (Medscape)

Knowing your local spider population can help you identify bites when they occur. Most spiders like to hide so always take care when you are clearing out dark areas or moving furniture.