Symptoms

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 any other symptoms.

Many skin sores look the same but have other causes, such as a bacterial infection.

Bites from some spiders, such as widow spiders and recluse spiders, might cause serious signs and symptoms.

Widow spider bites

Signs and symptoms of a widow spider bite can include:

• Redness, pain and swelling. You might have pain and swelling around the bite, which can spread into your abdomen, back or chest.
• Cramping. You might have severe abdominal rigidity or cramping, which is sometimes mistaken for appendicitis or a ruptured appendix.
• Nausea, vomiting, tremors or sweating. You might experience nausea, vomiting, tremors or sweating alone or in combination.

Symptoms can last 1 to 3 days.

Recluse spider bites

Signs and symptoms of a recluse spider bite can include:

• Increasing pain over the first eight hours after the bite
• Fever, chills and body aches
• A bite wound with a pale center that turns dark blue or purple with a red ring around it
• A bite wound that grows into an open sore (ulcer) with the skin around it dying

When to see a doctor

Seek medical care immediately if:

• You were bitten by a dangerous spider, such as a widow or recluse.
• You're unsure whether the bite was from a dangerous spider.
• You have severe pain, abdominal cramping or a growing wound at the bite site.
• You're having problems breathing or swallowing.
• The area of the sore has spreading redness or red streaks.