SymptomsBy Mayo Clinic staff
Typically, a spider bite looks like any other bug bite — a red, inflamed, sometimes itchy or painful bump on your skin — and may even go unnoticed. Harmless spider bites usually don't produce other symptoms.
Black widow spider bites
Signs and symptoms of a black widow spider bite may include:
- Pain. Typically beginning within an hour of being bitten, pain can spread from the bite site into your abdomen, back or chest.
- Cramping. Abdominal cramping or rigidity can be so severe that it's sometimes mistaken for appendicitis or a ruptured appendix.
- Sweating. Excessive sweating can occur around the bite mark or may involve the entire limb.
Brown recluse spider bite
The pain associated with a brown recluse spider bite typically increases during the first eight hours after the bite. The bite usually heals on its own in about a week. In a minority of cases, the skin at the center of the bite can become dusky red and then evolve into a deep open sore (ulcer) that enlarges as the surrounding skin dies. The ulcer usually stops growing within 10 days after the bite, but full healing can take months.
When to see a doctor
Seek prompt medical assistance if you believe you've been bitten by a spider and you're experiencing:
- Severe pain
- Abdominal cramping
- A growing ulcer at the bite site
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