The clinical standard
Toxicologists require the spider to be observed biting, captured, and identified by an arachnologist. Without all three, the diagnosis is presumptive.
Spreading redness, pus, or fever is more consistent with infection (especially MRSA) than with a spider bite.
References
- [1]Spider Bites - American Academy of Dermatology. Accessed June 2026.
Related in FAQ
- What spider is in my house?The most common indoor spiders in North America are cellar spiders, common house spiders (Parasteatoda tepidariorum), and in the Pacific Northwest, giant house spiders..
- Do spiders actively hunt or seek out people?No.
- Should I kill spiders I find in my house?For most species the practical answer is no: indoor spiders consume other pest arthropods.
- I found a spider in my bed - is that a problem?Spiders do not seek out beds or sleeping people.
- How can I tell if a spider is a brown recluse?Diagnosis rests on three combined features: six eyes arranged in three pairs (dyads), a uniformly colored abdomen with no pattern, and legs that are also uniform with no banding or spines.
- Is it normal to have spiders in my basement?Yes.