Insect and Spider Bites: When to Worry
The Bottom Line
Insect and spider bites can cause pain, redness, swelling, and itching. Black widow spiders cause muscle cramps, while brown recluse spiders cause necrotic lesions. Allergic reactions include hives, difficulty breathing and sometimes death. Infection and disease transmission can occur.
Signs and symptoms of an insect or spider bite
Initial signs and symptoms of an insect sting or bite can include stinging sensation, pain, redness, swelling, itching, and bumps at the site of the bite. The severity of symptoms varies from person to person. In some people, the bite site becomes large, swollen, warm to touch, very red, and painful. If the person is allergic to the insect’s venom, nausea, numbness, tingling, hives, wheezing, and difficulty breathing can develop. Depending on the severity of the allergy and time to treatment, death is possible in sensitive people. Allergic reactions can occur with any insect sting, but is most common with stings from bees, wasps, and hornets.
Black widow spider bites cause a stinging sensation and produce redness at the bite site. Later, there is cramping and muscle twitching near the bite site which progresses to the chest, back, or abdomen. Brown recluse spider bites cause a painful burning sensation which then develops into a lesion that becomes necrotic (signifying dead tissue).
Venomous spiders and insects to look out for
There are many biting/stinging insects to look out for including mosquitoes, fleas, fire ants, bed bugs, bees, wasps, and hornets. Some insects, such as blister beetles, produce toxins that cause skin irritation and blisters when they get on the skin.
Spiders are not insects; they are arachnids and differ from insects in number of body segments and legs; spiders also lack wings and antennae.
Is my bite dangerous?
Your bite is dangerous if you have an allergic reaction or if the site of the bite becomes infected.
Mosquitoes can transmit diseases such as West Nile virus and malaria. If you live in an area where mosquito-borne disease is known to occur, a bite can be dangerous if the mosquito is carrying the disease. Depending on what diseases are known to be widespread in the area, you should be monitored for the development of specific disease-related symptoms.
Is my bite infected?
Watch for pus, swollen glands, and worsening swelling, as well as redness and pain in and around the site of the bite.
Treating a bite
If you are in an area with a lot of insects or spiders, move to a safer area. If there is a stinger in your skin, remove it by scraping it off with the back of a knife, edge of a credit card, or other straight-edged object. The barbed stinger may look like a small, dark dot. Do not use tweezers.
Wash the area with soap and water. Put cold water or a cloth filled with ice on the bite for 10-20 minutes. If it itches, take a nonprescription antihistamine by mouth. Put 0.5-1% hydrocortisone cream or calamine lotion or baking soda paste on it. You may need to do this a few times a day until you feel better. If it is an insect bite, it should resolve within 1-2 days. You may need antibiotics if the bite gets infected. Some brown recluse spider bites require surgical intervention of the wound site. You may need a tetanus shot after a spider bite.
When should I seek help?
If you experience an insect bite or sting and your local symptoms worsen significantly, experience systemic symptoms (such as symptoms affecting body organs other than the bite site), or have a history of allergic reactions, you should seek help. If you think you were bitten by a venomous spider (such as a black widow or brown recluse), you should also seek help.
Help from experts is available through the webPOISONCONTROL online tool and by phone at 1-800-222-1222. Poison Control’s expert guidance is always free, confidential, and available 24 hours a day.
Clinical Toxicologist
Poisoned?
Call 1-800-222-1222 or
Prevention Tips
- Avoid areas with a lot of insects and/or spiders.
- Avoid wooded areas and areas with a lot of small bushes and trees.
- Stay indoors at dusk and dawn when mosquitoes are most active.
- Use screens on windows and doors.
- Remove standing water to decrease mosquito breeding.
- Wear long-sleeved shirts, pants, and a hat.
- Wear gloves when gardening.
- Use insect repellant.
- Avoid wearing perfumes, colognes and other scented products.
- Cover food and drinks if eating outdoors.
- Carry an epi autoinjector if you have severe allergic reactions to bites or stings.
- Wear a medical ID bracelet or necklace if you have allergic reactions.
This Really Happened
A 3-year-old boy was bitten by a black widow spider, which was found in his helmet. He immediately complained of ear pain. He developed abdominal pain, difficulty breathing, and grunting respirations. Because of profound drowsiness and worsening respiratory distress, he was intubated and admitted to an intensive care unit. He was treated with supportive care and recovered in a few days.
For More Information
References
Poisoned?
Call 1-800-222-1222 or
Prevention Tips
- Avoid areas with a lot of insects and/or spiders.
- Avoid wooded areas and areas with a lot of small bushes and trees.
- Stay indoors at dusk and dawn when mosquitoes are most active.
- Use screens on windows and doors.
- Remove standing water to decrease mosquito breeding.
- Wear long-sleeved shirts, pants, and a hat.
- Wear gloves when gardening.
- Use insect repellant.
- Avoid wearing perfumes, colognes and other scented products.
- Cover food and drinks if eating outdoors.
- Carry an epi autoinjector if you have severe allergic reactions to bites or stings.
- Wear a medical ID bracelet or necklace if you have allergic reactions.
This Really Happened
A 3-year-old boy was bitten by a black widow spider, which was found in his helmet. He immediately complained of ear pain. He developed abdominal pain, difficulty breathing, and grunting respirations. Because of profound drowsiness and worsening respiratory distress, he was intubated and admitted to an intensive care unit. He was treated with supportive care and recovered in a few days.