Is it a bite or a sting? How can you tell? Many people are terrified of spiders and rightfully so! Their bites can be excruciatingly painful and in severe cases, deadly. Luckily, we found this guide from Dr. Stuart Mitchell that will help differentiate between bites and stings as well as two of the most common types of biting spiders in Florida: the Brown Recluse spider and the Black Widow spider.
Bite or Sting?
- Offensive (typically).
- Venom injected via structures of the mouth (fangs).
- May result in tissue destruction, allergic reaction, paralysis, and/or death.
- Defensive (typically).
- Venom injected via tapered, posterior structure (modified ovipositor or "stinger").
- Immediate pain (usually non-fatal); an allergic reaction possible.
*Venom composition, potency, and toxicity vary by spider species. For example, hunting spiders have more potent venoms than web-spinning spiders (except for Widow spiders (Latrodectus spp.). Only a few spider species can cause injury.
- Most spiders do not have enough venom.
- Most toxins are not harmful to humans.
- Fangs cannot penetrate human skin.
- It is doubtful that there are any truly "deadly" spiders (bites that can be anticipated to cause deaths in humans).
- Envenomation of toxic spider compounds may cause skin lesions, systemic illness, neurotoxicity, and potentially death.
- Venoms are composed of complex proteins and proteolytic enzymes designed to incapacitate and/or initiate digestion of prey.
- Tarantulas have venom, but barbed, urticating hairs can irritate eyes, skin, and mucous membranes.
Two main clinical syndromes
Bite from a Black Widow spider (Latrodectism)
- Sharp pain at bite site.
- Spider often seen.
- Severe muscular contractions of large muscles.
- SLUDGE (salivation, lacrimation or eyes watering, urination, defecation, GI distress, vomiting, and bronchorrhea or excessive mucus).
- Hypertension, tachycardia, fasciculations (twitching), fever, and diaphoresis (sweating).
- Usually symptom resolution.
- Death is rare.
Bite from a Brown Recluse spider (Loxoscelism)
- Local bite often not noticed or stinging sensation.
- Severe pain and itching.
- Possible clear or hemorrhagic vesicle to dark eschar.
- Eschar sloughs and can have progressive necrosis.
- In extreme cases, hemolytic anemia or red blood cell destruction, rash, arthalgias (joint pain), fever/chills, nausea/vomiting, and renal failure.
- Death is rare.