Arizona has the highest number of scorpion stings reported in the country. An average of 11,500 stings are reported to poison centers each year in Arizona. These occur throughout the year, with most calls occurring between June and August. Anne-Michelle Ruha, MD, a toxicologist and professor at the University of Arizona College of Medicine – Phoenix discusses, what Arizona residents need to know about scorpion stings. 

Q: How can you tell which scorpions in Arizona are dangerous? 

A: All scorpions can sting, but in Arizona only the bark scorpion has a neurotoxin in its venom that can produce a dangerous reaction in humans. Bark scorpions are yellowish in color and small, growing up to about 3 inches in length. One of the best ways to distinguish them from other similar-sized scorpions is by their behavior. They are commonly found inside homes and can climb up walls and along ceilings. Outdoors, they may be found in trees, under rocks, in crevices and on patio furniture and walls. 

Anne-Michelle Ruha, MD

Q: Is it true that baby scorpions are most venomous?

A: It is not true that baby scorpions are more venomous than adults. The small size of the Arizona bark scorpion as compared to some other local species such as the Desert Hairy scorpion may have led to the idea that ‘baby’ scorpions are more dangerous. 

Q: What should you do if stung by a scorpion?

A: Most bark scorpion stings result in a painful tingling sensation that improves over hours to days. No special treatment is needed for the majority of stings. Cool compresses may provide some relief for the stinging pain, and over-the-counter analgesics such as acetaminophen or ibuprofen may be helpful. Bark scorpion stings do not cause swelling or redness, and the pain is not the result of an allergic reaction. Antihistamines such as diphenhydramine and other allergy medications are not useful to treat a bark scorpion sting. On the other hand, stings from some other Arizona scorpions may rarely cause local inflammatory and allergic reactions. The Banner Poison and Drug Information Center (1-800-222-1222) is an outstanding resource for information and advice if you are stung. 

Q: In what situation should you go to the emergency room? If it is a child who is stung, does that make a difference? 

A: Although most stings only result in pain at the sting site, more serious reactions can occur that require treatment in a hospital. Neurotoxins in venom can produce painful tingling and numbness throughout the whole body, as well as abnormal eye movements, muscle jerking and difficulty breathing. Children are more likely than adults to experience a severe reaction, and should be seen in an emergency department if one occurs. Adults rarely experience life-threatening reactions after a scorpion sting, but sometimes the venom effects make it difficult to see or walk normally, in addition to causing severe pain. The Banner Poison and Drug Information Center (1-800-222-1222) is an excellent resource for advice on whether to stay at home or go to an emergency department to be evaluated and treated.

Q: Why is antivenom so expensive? When is it needed?  

A: The manufacture of antivenom is complex, and approval by the United States Food and Drug Administration is a lengthy and expensive process. This leads to a high price tag for antivenom and on top of that, hospitals add their own mark-up. Whether scorpion antivenom is ever truly needed is debatable. Without antivenom, the most severe effects of a scorpion envenomation will resolve within 24 hours, but a person might require an intensive care unit admission, high doses of sedative medications, and may even need to be placed on a breathing machine while waiting for the effects of the venom to wear off. In most cases, scorpion antivenom can stop all of the effects quickly, allowing a patient to go home from the emergency department and avoid hospital admission. Scorpion antivenom is a good option for anyone with a sting severe enough that it requires hospitalization. 

Q: After a scorpion sting should you receive follow-up care from your primary care doctor?

A: Most bark scorpion stings don’t require any special treatment or follow up with a physician. Although even small skin punctures may increase risk of infection for some individuals, scorpion stings are not generally associated with infection, and antibiotics or special monitoring for infection is unnecessary. If you are admitted to the hospital with a severe scorpion envenomation, you will probably be advised to follow up with your doctor for a recheck within a few weeks. 

Q: What steps can Arizonans take to make sure they don’t get stung by a scorpion? 

A: Scorpions are a fact of life in Arizona and it is hard to guarantee that you will never be stung, but there are steps that you can take to avoid a sting. Most stings occur in the home. Always wear shoes, both indoors and outdoors. Shake your shoes and clothes out before putting them on. Since bark scorpions cannot climb smooth surfaces, you can place glass jars around crib or bed legs to help protect children. When outdoors, a good rule of thumb in Arizona is to watch where you step and watch where you reach. This will go a long way in preventing both scorpion stings and rattlesnake bites.

Q: I’ve heard that red onions and garlic soothe scorpion stings. Is this true? 

A: There is no scientific evidence to support use of red onion or garlic to soothe scorpion stings. Red onion and garlic have been used as home remedies for bee stings, and there are plenty of recommendations online to use red onions on a scorpion sting. This is based on the idea that chemicals in onions reduce inflammation caused by bee venom. This theory cannot be applied to bark scorpion stings since they do not produce swelling and inflammation at the sting site. The mechanism of action and the effect of bark scorpion venom are entirely different than that of bee venom.