MedicineNet provides pictures of spider bites. The pictures focus on bites from the black widow spider and the brown recluse spider, the only two species of spiders in the United States that are harmful.
In the United States, most spiders are not poisonous, and individuals can treat most spider bites at home, according to MedicineNet. The majority of presumed spider bites are actually other conditions that cause symptoms similar to those of spider bites. Non-poisonous spider bites cause localized redness, itching and pain. Brown recluse and black widow bites can cause fever, nausea, headaches and abdominal pain. Black widow bites are rarely fatal, but they typically affect children and the elderly more severely.