Summary about Disease
A brown recluse spider bite can cause a range of reactions, from mild irritation to severe tissue damage. The venom contains enzymes that can break down cell membranes, leading to localized tissue necrosis (death). The severity of the bite depends on the amount of venom injected and the individual's sensitivity. Not all bites result in significant symptoms.
Symptoms
Initial Bite: Often painless; may feel a slight sting.
Localized Pain: Develops within a few hours.
Redness: The area around the bite becomes red.
Blister: A blister may form at the site.
"Red, White, and Blue" Sign: A characteristic pattern of redness, followed by a blanched (white) area, and then a bluish or purplish discoloration.
Necrosis: Tissue death (necrosis) can occur, leading to an open sore. This can take days or weeks to develop.
Systemic Symptoms (Rare): Fever, chills, nausea, vomiting, joint pain, rash, and, very rarely, kidney damage or hemolysis (destruction of red blood cells).
Causes
Brown Recluse Spider Bite: The bite of a brown recluse spider ( Loxosceles reclusa*). These spiders are typically found in dark, secluded places like closets, attics, and woodpiles. Bites usually occur when the spider is trapped against the skin.
Medicine Used
Wound Care: Keeping the wound clean and bandaged.
Pain Relief: Over-the-counter pain relievers like ibuprofen or acetaminophen. Stronger pain medication may be needed for severe pain.
Antibiotics: If a secondary bacterial infection develops.
Tetanus Booster: To prevent tetanus infection.
Dapsone: An antibiotic sometimes used to try to reduce the severity of necrosis, but its effectiveness is debated.
Skin Grafting: In severe cases of necrosis, skin grafting may be required to repair the damaged tissue.
Colchicine: This medication has been studied, but there isn't enough evidence to prove its benefits.
Hyperbaric Oxygen Therapy: Limited evidence supports the routine use of hyperbaric oxygen therapy for brown recluse spider bites. It might be considered in specific cases where tissue damage is severe and not responding to other treatments.
Is Communicable
No. Brown recluse spider bites are not contagious. They are caused by the venom injected by the spider and cannot be spread from person to person.
Precautions
Reduce Spider Habitat: Eliminate clutter in basements, attics, and closets. Seal cracks and crevices in the home's foundation and around pipes.
Wear Protective Clothing: Wear gloves, long sleeves, and long pants when handling firewood, working in the garden, or cleaning out storage areas.
Shake Out Clothing and Shoes: Shake out clothing and shoes before wearing them, especially if they have been stored in areas where spiders might be present.
Inspect Bedding: Carefully inspect bedding before getting into bed, especially in infrequently used rooms.
Use Insecticides: Consider using insecticides around the perimeter of the home to control spider populations.
How long does an outbreak last?
There is no "outbreak" in the traditional sense of a communicable disease. A person might experience symptoms from a bite for several weeks or even months, especially if necrosis develops. The healing process depends on the severity of the bite and individual factors. The wound from necrosis can last for several months.
How is it diagnosed?
History and Physical Exam: Diagnosis is primarily based on the patient's history (being bitten by a spider), the appearance of the bite wound, and the exclusion of other possible causes.
Geographic Location: Important for considering the likelihood of brown recluse spider presence.
No Specific Lab Test: There is no specific lab test to confirm a brown recluse spider bite.
Ruling Out Other Conditions: Other conditions that can mimic brown recluse bites need to be ruled out.
Timeline of Symptoms
0-8 Hours: Bite may be painless initially or cause mild stinging. Pain and redness develop.
12-24 Hours: Pain intensifies. The characteristic "red, white, and blue" sign may appear. Blister formation.
24-72 Hours: Necrosis may begin to develop. Systemic symptoms (rare) may appear.
Days to Weeks: Necrotic ulcer expands. Healing process begins (can be slow).
Weeks to Months: Complete healing, potentially with scarring.
Important Considerations
Not all bites cause severe reactions. Many bites result in only minor, localized symptoms.
Secondary bacterial infections are a potential complication.
Misdiagnosis is common. Many skin lesions are incorrectly attributed to spider bites. Other causes should be considered.
Prompt medical evaluation is recommended if symptoms are significant or worsen.
Children are more susceptible to systemic symptoms.
Prevention is key. Taking precautions to avoid spider bites is the best approach.