Javascript required
Skip to content Skip to sidebar Skip to footer

How Big Do Brown Recluse and Black Widow Spiders Get

eMedicineHealth

  • Black Widow vs. Brown Recluses
    • What Are Black Widow and Brown Recluse Spiders?
  • Symptoms
    • What Are Symptoms of Spider Bite?
  • Treatment
    • How to Treat Spider Bite
    • When to Seek Medical Care
  • Guide
    • Black Widow and Brown Recluse Spider Bite Topic Guide
    • Doctor's Notes on Wilderness: Black Widow and Recluse Spider Bite Symptoms

What Are Black Widow and Brown Recluse Spiders?

Black Widow Spider vs. Brown Recluse Spider

Black widow spider. Note the characteristic hourglass abdominal markings. Brown recluse spiders (Loxosceles recluse) are tan to dark brown with a leg span of approximately 1 inch.

  • Black widow spiders (Latrodectus mactans) may be black or brown with a leg span of approximately one to two inches. Most can be identified by a red hourglass marking on the abdomen.
  • Black widow spiders are located throughout the United States.
  • Black widow toxin causes nerve cell dysfunction and muscle cell twitching.
  • Brown recluse spiders (Loxosceles recluse) are tan to dark brown with a leg span of approximately 1 inch. Many have a violin-shaped marking on the chest.
  • Brown recluse spiders are located mainly in the south-central United States.
  • Both the black widow and brown recluse spiders are common in North America and throughout the world. Human contact with these spiders is usually accidental.

What Are Symptoms of Spider Bite?

  • Readers Comments 2
  • Share Your Story

Black widow spider. Note the characteristic hourglass abdominal markings

Black widow spider. Note the characteristic hourglass abdominal markings

Black widow spider bites result in a halo lesion consisting of a pale circular area surrounded by a ring of redness.

  • The initial bite of the black widow spider is usually painful, and the victim will often note the spider during the bite.
  • Numbness, tingling, rashes, sweating, nausea, vomiting, dizziness, cramps, rigid abdominal muscles, chest tightness, weakness, and difficulty breathing may occur.
  • The abdominal pain due to the spider bite can be so severe that it mimics abdominal medical conditions such as pancreatitis.
  • Hypertension (high blood pressure) is a possible reaction to the venom.

Brown recluse spider. Note the violin pattern on cephalothorax and light-colored, hairless abdomen.

Brown recluse spider. Note the violin pattern on cephalothorax and light-colored, hairless abdomen.

Brown recluse bites are tender, red, swollen, and form blisters. The initial bite may or may not be noticed by the victim.

  • Brown recluse bites cause local swelling, pain, itching, redness, tenderness, and blisters. They eventually form large ulcers and may cause tissue necrosis (death of the tissue in the area of the bite).
  • Fever, chills, rash, nausea, and vomiting may develop.
  • More severe reactions include kidney failure, blood coagulation abnormalities, and difficulty breathing. Death can occur. Symptoms of an allergic reaction may be present.

QUESTION

Emotional trauma is best described as a psychological response to a deeply distressing or life-threatening experience. See Answer

When to Seek Medical Care

  • Seek immediate medical care.
  • Antivenom therapy is available for black widow bites. Medications, if started early, are available to treat brown recluse bites. However, the efficacy of the medications for the treatment of brown recluse spider bites is controversial.
  • Consult a doctor about treatment with available medications.

From WebMD Logo

Reviewed on 9/30/2021

References

Medically reviewed by Robert L. Cox, MD; Board Certification Internal Medicine/Infectious Disease

REFERENCE:

"Clinical manifestations and diagnosis of widow spider bites"
UpToDate.com

"Bites of recluse spiders"
UpToDate.com

https://www.uptodate.com/contents/management-of-widow-spider-bites?search=black%20widow%20spider%20bite%20treatment&source=search_result&selectedTitle=1~150&usage_type=default&display_rank=1

Patient Comments & Reviews

  • Black Widow and Brown Recluse Spider Bite - Symptoms

    What symptoms did you experience as a result of a spider bite?

    Post View 2 Comments
  • Black Widow and Brown Recluse Spider Bite - Treatment

    What treatment did you receive for your spider bite?

    Post

How Big Do Brown Recluse and Black Widow Spiders Get

Source: https://www.emedicinehealth.com/wilderness_black_widow_and_recluse_spider_bite/article_em.htm