Most spider bites are NOT dangerous.
Most bites cause mild redness and swelling that clears up on its own. Many of the more severe images in our collection are the result of delayed treatment or an allergic reaction, not the venom itself.
What does a bite with a red line mean?
A red line extending from a bite site is a warning sign that should not be ignored. It usually indicates lymphangitis – a condition where bacteria have entered the lymphatic vessels near the bite and are spreading through the body. This is a sign of infection, not venom.
If you notice a red line extending from your bite, go to the emergency room the same day. Left untreated, the infection can spread rapidly and cause life-threatening complications including sepsis.
While waiting for medical attention, keep the area clean and do not scratch or pick at the bite as this introduces more bacteria into the wound.
What does a bite with a red circle mean?
A red circle around a bite is not necessarily a spider bite at all. A circular red rash – particularly one that expands over days – is the classic sign of erythema migrans, which is the rash associated with Lyme disease transmitted by tick bites, not spiders.
If you notice a circular red rash appearing 3 to 30 days after a bite, accompanied by flu-like symptoms such as fever, headache, or fatigue, see a doctor immediately and mention the possibility of Lyme disease. Left untreated, Lyme disease can cause joint pain, heart problems, and neurological complications.
If you find a tick still attached to your skin, remove it promptly with tweezers, gripping as close to the skin as possible, and monitor the site for any developing rash.
Compare your bite to our photo library
Browse the photos above to compare what you are seeing. If you are still unsure what bit you, visit our spider bite identification guide or browse individual spider pages for more specific photos.
Note: Many pest control companies offer perimeter bug treatments that can help prevent spiders from entering your home. Ask your local hardware store for options.
