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Scorpion stingsBy Mayo Clinic staff
Original Article: http://www.mayoclinic.com/health/scorpion-stings/DS01113
Scorpion stings — although painful — are mostly harmless. As many as 1,500 species of scorpions have been described worldwide, but only about 30 of these are considered dangerous. In the United States, only the bark scorpion, found mainly in the desert Southwest, has venom potent enough to cause severe symptoms. Elsewhere, lethal scorpion stings occur predominantly in Mexico, South America, parts of Africa, the Middle East and India.
Scorpion stings are most serious in young children, older adults and pets. In the United States, healthy adults usually don't need treatment for scorpion stings, but if your child is stung, always get immediate medical care.
Most scorpion stings in the United States cause only minor signs and symptoms, such as pain and warmth at the sting site. The venom of the bark scorpion, which is native to Arizona, New Mexico and the California side of the Colorado River, is more toxic and can be life-threatening, particularly in children.
Children who have been stung by a bark scorpion might experience:
- Pain, which can be intense, numbness and tingling in the area around the sting, but little or no swelling
- Muscle twitching or thrashing
- Unusual head, neck and eye movements
- Restlessness or excitability and sometimes inconsolable crying
Adults are more likely to experience:
- Rapid breathing
- High blood pressure
- Increased heart rate
- Muscle twitching
When to see a doctor
It's always best to be safe. If you or your child is stung, follow these guidelines:
- Get immediate medical care for any child stung by a scorpion.
- If you've been stung, get prompt care if you begin to experience widespread symptoms.
- If you're concerned about a scorpion sting — even if your reaction is minor — call your local poison control center for advice.
- Seek medical attention right away if you or your child is stung while traveling in another country.
Scorpions are arthropods — a relative of insects, spiders and crustaceans — and have changed little in the last 400 million years or so.
The average scorpion is about 3 inches (7.6 centimeters) long, but different species can be much smaller or larger. At 8 inches (20 centimeters), the African scorpion is probably the world's longest. Scorpions have eight legs and a pair of crab-like pinchers, giving them a certain fierce look. The venom is carried in a gland on the back of the tail, and when on the attack, a scorpion can flick its stinger over its head with lightning speed. The venom itself contains a complex mix of toxins that affect the nervous system (neurotoxins).
Many people think of scorpions as dangerous pests, but they play a critical role in the ecosystem, consuming large quantities of other arthropods and even small snakes and mice. They're also shy, nocturnal creatures that resist stinging unless provoked or attacked. They can control the amount of venom they release — depending on how threatened they feel — so some stings may be almost entirely venomless.
Certain factors can increase your risk of a scorpion sting:
- Location. In the United States, scorpions mainly inhabit the desert Southwest, particularly Arizona. Worldwide, they're found most often in Mexico, northern and southern Africa, South America, the Middle East and India. Scorpions are adaptable, and they've also been discovered in the Himalayas and Hawaii.
- Environment. Bark scorpions live under rocks, logs and tree bark — hence, the name — and you're especially likely to encounter them when you're hiking or camping. But they're also the most common house scorpion, hiding in firewood, garbage pails, bed linen and shoes.
- Season. Scorpions are most active in spring and summer, when nighttime temperatures hover above 70 F (21 C).
- Travel. Not only are you more likely to encounter dangerous scorpions while traveling in developing countries, you might bring them home with you. Scorpions can hide in clothing, luggage and shipping containers.
As with stinging insects, such as bees and wasps, you can have an allergic reaction to a scorpion sting — sometimes severe enough to be life-threatening (anaphylaxis). Signs and symptoms are similar to those of bee stings and can include hives, trouble breathing, and nausea and vomiting. An allergic reaction may be wrongly attributed to the venom, which can cause different, but also dangerous, symptoms.
The very old and the very young are most likely to die of untreated venomous scorpion bites. The cause is usually heart or respiratory failure occurring some hours after the sting. Very few deaths from scorpion stings have been reported in the United States.
Preparing for your appointment
If you can find the scorpion that stung you or your child, bring it with you to the hospital. Identifying the type of scorpion may make treatment easier.
Tests and diagnosis
Your history and symptoms are usually all that your doctor needs to make a diagnosis. If you have severe symptoms, you may have blood or imaging tests to check for the effects of the venom on your liver, heart, lungs and other organs.
Treatments and drugs
Most scorpion stings don't need medical treatment. But if symptoms are severe, supportive care in a hospital is usually required. In addition to bed rest, this might include sedatives for muscle spasms and intravenous drugs to manage elevated blood pressure, agitation and pain.
An antivenin called Anascorp can be given to help treat the stings of bark scorpions. Anascorp is made from the blood plasma of horses immunized with scorpion venom. Studies show it to be effective within four hours of being administered, which can help prevent extended stays in an intensive care unit. Side effects may include vomiting, fever and rash. Some people sensitive to horse proteins could experience an allergic reaction.
Lifestyle and home remedies
If a scorpion stings you or your child, follow the suggestions below. Healthy adults may not need further treatment, and these tips can help keep children safe until they see a doctor:
- Wash the wound with soap and water.
- Apply cold compresses to the affected area to ease the pain and slow the venom's spread. This is most effective in the first two hours after a sting occurs.
- Try to stay calm and quiet so that the poison spreads more slowly.
- Don't consume food or liquids — stings can cause throat swelling and difficulty swallowing.
- Over-the-counter pain relievers, such as nonsteroidal anti-inflammatory drugs (Advil, Motrin, others), can help ease discomfort. But avoid using narcotic pain medications, which can suppress breathing.
Scorpions tend to avoid contact. To prevent chance meetings:
- Remove trash, logs, boards, stones, bricks and other objects that would make good hiding places for scorpions from around your home.
- Keep grass closely mowed, and prune bushes and overhanging tree branches, which can provide a path to your roof for scorpions.
- Store garbage containers in a frame that allows them to rest above ground level.
- Caulk cracks, install weatherstripping around doors and windows, and repair torn screens.
- Avoid storing firewood inside your house.
- Always wear shoes outdoors, especially around water sources, such as swimming pools and fountains.
- Shake out your shoes and clothing before wearing them in areas where scorpions are common.
- When hiking or camping, wear long sleeves and pants and check your sleeping bag and clothing for scorpions every evening.
- When traveling in other countries — especially if you're camping or staying in rustic accommodations — shake out your clothing and bedding often and sleep under a mosquito net. If you have a known allergy to insect stings, carry an epinephrine injector, such as EpiPen.
- Carefully move a scorpion. If you find a scorpion near your home or campsite, don't panic. Use tongs to gently remove the scorpion to a safer location.
- American Association of Poison Control Centers. 2008 annual report of the American Association of Poison Control Centers' national poison data system (NPDS). Clinical Toxicology. 2009;47:911. http://www.aapcc.org/dnn/Portals/0/2008annualreport.pdf. Accessed Sept. 21, 2010.
- Suchard JR. Scorpion envenomation. In: Auerbach PS. Wilderness Medicine. 5th ed. Philadelphia, Pa.: Mosby Elsevier; 2007. http://www.mdconsult.com/das/book/body/219470238-2/1055986458/1483/419.html#4-u1.0-B978-0-323-03228-5..50052-5_2506. Accessed Sept. 20, 2010.
- Gouge DH, et al. Scorpions. The University of Arizona. http://ag.arizona.edu/pubs/insects/az1223. Accessed Sept. 20, 2010.
- Scorpion stings. The Merck Manuals: The Merck Manual for Healthcare Professionals. http://www.merck.com/mmpe/print/sec21/ch325/ch325h.html. Accessed Sept. 20, 2010.
- Chippaux JP, et al. Epidemiology of scorpionism: A global appraisal. Acta Tropica. 2008;107:71.
- Animal-associated hazards. Centers for Disease Control and Prevention. http://wwwnc.cdc.gov/travel/yellowbook/2010/chapter-2/animal-associated-hazards.aspx. Accessed Sept. 20, 2010.
- Boyer LV, et al. Antivenom for critically ill children with neurotoxicity from scorpion stings. New England Journal of Medicine. 2009;360:2090.
- What to do in a medical emergency: Bites and stings. American College of Emergency Physicians Foundation. http://www.emergencycareforyou.org/EmergencyManual/WhatToDoInMedicalEmergency/Default.aspx?id=210#spider_bites_and_scorpion_stings. Accessed Sept. 20, 2010.
- FDA approves the first specific treatment for scorpion stings. Food and Drug Administration. http://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/ucm266611.htm. Accessed Aug. 4, 2011.