Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.
Dr. Shiel received a Bachelor of Science degree with honors from the University of Notre Dame. There he was involved in research in radiation biology and received the Huisking Scholarship. After graduating from St. Louis University School of Medicine, he completed his Internal Medicine residency and Rheumatology fellowship at the University of California, Irvine. He is board-certified in Internal Medicine and Rheumatology.
Bites from most (non-poisonous) spiders cause local redness, irritation, and pain that usually can be treated at home using an over-the-counter pain reliever along with application of cooling packs or a wet cloth to relieve swelling. These local reactions usually resolve without treatment over a period of 7-10 days. Rarely, an individual can have an allergic reaction to a spider bite, even to a bite from a non-poisonous spider, but allergic reactions are more likely to be due to contact with a spider than from a spider bite.
A black widow spider bite is said to feel like a pinprick, although victims may not realize that they have been bitten. Sometimes double fang marks may be seen at the location of the bite. The most common localized symptoms of a black widow spider bite are immediate pain, burning, swelling, and redness.
Picture of the underside of a black widow spider and an egg sack
The bite of a brown recluse spider leads to a mild stinging, followed by local redness and severe pain that usually develops within eight hours but may occur later. Some reports of brown recluse bites describe a blue or purple area around the bite, surrounded by a whitish ring and large red outer ring in a "bull's eye" pattern. A fluid-filled blister forms at the site and then sloughs off to reveal a deep ulcer that may turn black.
Picture of a brown recluse spider. Note the violin pattern on the cephalothorax and light-colored hairless abdomen.
Picture of a brown recluse spider
Picture of a brown recluse spider head close-up
Generalized symptoms of bites from black widow and brown recluse spiders may include:
While black widow spider bites are hardly ever fatal, rare deaths have occurred from brown recluse spider bites and are more common in children than in adults.
If a spider was not observed inflicting the bite, it is difficult if not impossible to determine whether a spider bite occurred, since many conditions of the skin may produce the same symptoms as a spider bite. Streptococcal and Staphylococcal infections,
early lesions of herpes
simplex or zoster, burns, stings or bites from other
arthropods or insects (including fleas, bedbugs, mosquitos, biting flies, ants,
and ticks), thorn injury, and early Lyme disease all may be characterized by
skin findings similar to those from a spider bite. Spiders rarely bite people,
and only if threatened. People often thing they have spider bites when the
irritation is from another cause.
Wash the site of the spider bite well with soap and water.
Apply a cool compress or ice pack over the spider bite location.
Over-the-counter pain relievers may be used to relieve symptoms. (Remember,
do not give aspirin to children; use acetaminophen or ibuprofen instead).
Call the doctor or seek emergency treatment if the victim is a young child,
if you think the bite may have been from a black widow or brown recluse spider,
if any signs of an allergic reaction occur, if the bite area becomes infected,
or if the victim develops a rash or severe illness.
If possible, retrieve the spider and bring it with you to the health care
practitioner so that it can be definitively identified.
A tetanus booster shot may be necessary, depending upon the date of the patient's last immunization.