Spider bites can cause redness, pain and swelling, or you might not notice them at all. Many other bug bites and skin sores cause redness, pain and swelling. So unless you actually saw a spider bite you, it's difficult to be certain that your wound was caused by a spider. Worldwide only a few species of spiders have fangs long enough to penetrate human skin and venom strong enough to hurt humans.
Among these are widow spiders, with about 30 species, and recluse spiders, with more than species worldwide. Typically, a spider bite looks like any other bug bite β a red, inflamed, sometimes itchy or painful bump on your skin β and may even go unnoticed.
Harmless spider bites usually don't produce any other symptoms. Bites from some spiders, such as widow spiders and recluse spiders, might cause serious signs and symptoms. Severe spider bite symptoms occur as a result of the venom that the spider injects.
Symptom severity depends on the type of spider, the amount of venom injected and how sensitive your body is to the venom. Risk factors for spider bites include living in areas where spiders live and disturbing their natural habitat.
Widow spiders and recluse spiders like warm climates and dark, dry places. Widow spiders can be found throughout the United States, except Alaska, and are more common in the rural South. They're also found in Europe.
