Because most spider bites don't go all the way through skin, they usually cause only mild reactions. However, black widow and brown recluse spider bites can cause serious reactions and need immediate care. Allergic reactions to spider bites can happen but are rare. Signs and Symptoms Of a brown recluse spider bite: swelling or redness around the bite pain around the bite within 2 to 8 hours joint stiffness or pain nausea, vomiting body rash fever, chills, and body aches tiredness Of a black widow spider bite: painful muscle cramps within 8 hours no bite on the skin (or only a small bite) belly pain and stiffness nausea and vomiting breathing trouble Of an allergic reaction: swelling of the face or mouth difficulty swallowing or speaking chest tightness, wheezing, or trouble breathing What to Do If your child has been bitten by a spider: Wash the area with soap and water. Put an ice pack or a cool wet cloth on the bite area to relieve pain and swelling. Get Medical Care Right Away if: Your child has any signs of an allergic reaction. Your child develops any kind of rash after a bite. Your child has severe pain or cramping. The area begins to look infected (increasing redness, pain, swelling, warmth, or pus). You think your child was bitten by a brown recluse spider or black widow spider. Think Prevention! Make sure garages, attics, and woodpiles are free of spider webs. Make sure kids wear long sleeves and pants when playing around garages, attics, and woodpiles, etc. Firewood should be kept outside the house to avoid bringing spiders inside. Back to Articles Related Articles Bug Bites and Stings Most bug bites and stings are just annoying. But some can cause infections and allergic reactions. It's important to know what to watch for, and when to get medical attention. Read More Hey! A Black Widow Spider Bit Me! The black widow spider is one of six poisonous kinds of spiders in the United States. Learn more about them! Read More Hey! A Brown Recluse Spider Bit Me! The brown recluse spider is one of six poisonous kinds of spiders in the United States. Learn more about the brown recluse spider. Read More A to Z: Insect Bites/Stings, Non-Venomous Bites from non-venomous insects are the result of an insect attempting to feed upon a person's blood. Non-venomous means the insect does not inject poisons through its bite. Read More A to Z: Insect Bites/Stings, Venomous Venomous insects bite or sting people as a way to defend themselves. They inject a poison (venom) into a person through their mouth or stinger which causes a reaction. Read More Bug Bites and Stings Generally, insect bites and stings are harmless. Find out how to keep pests from ruining your fun. Read More Note: All information is for educational purposes only. For specific medical advice, diagnoses, and treatment, consult your doctor. © 1995-2021 KidsHealth®. All rights reserved. Images provided by The Nemours Foundation, iStock, Getty Images, Veer, Shutterstock, and Clipart.com.