Scorpion Allergy

Symptoms, Diagnosis, and Treatment of Scorpion Stings

Who is at risk for scorpion allergy, what are the symptoms, and how is it treated?. Jeffrey Demain, MD

What is a Scorpion?

Scorpions are found around the world. They are not insects; they are arachnids, and are closely related to spiders, mites and ticks. Scorpions have the ability to kill prey by injecting venom from a stinger located at the end of a long tail. Because many scorpions are found indoors, people are frequently stung by scorpions.

The common striped scorpion, Centruroides vittatus, is the most commonly encountered scorpion in the United States.

It is responsible for thousands of human scorpion stings every year, most of which are harmless other than causing a moderate amount of pain at the site of the sting. The venom of the common striped scorpion is of low toxicity, and has only caused a few human deaths. The venom is responsible for neurotoxic symptoms in humans, including numbness and tingling throughout the body of the victim.

What is Scorpion Allergy?

As with other stinging insects, such as honeybees and yellow jackets, scorpion stings also are known to sometimes cause allergic reactions, including anaphylaxis. In many cases, allergic reactions from scorpion stings are wrongly attributed to the neurotoxins in the venom.

Symptoms of allergic reactions as a result of a scorpion sting can be identical to those from a honeybee sting, including:

  • Hives and swelling
  • Asthma symptoms
  • Allergic rhinitis symptoms
  • Nausea, vomiting and diarrhea
  • Sense of panic or feeling of impending doom
  • Metallic taste in the mouth

How is Scorpion Allergy Diagnosed?

Currently, there is no commercially available test to diagnose scorpion allergy. Recently, we studied a group of people who had experienced allergic reactions as a result of scorpion stings, and were able to prove that these people had an allergic antibody against scorpion venom.

Testing included experimental skin testing as well as a blood test similar to RAST. At the present time, only a few research centers are able to diagnose an allergic reaction to scorpion venom.

It is important for physicians and victims of scorpion stings to realize that allergic reactions to scorpion venom are possible, and that symptoms should not always be attributed to neurotoxins.

Who is at Risk for Developing an Allergy to Scorpions?

Typically, in order for an allergic reaction to occur, a person must have been exposed to the substance in the past. After an initial exposure, allergic antibodies are produced. Then, with a subsequent exposure, an allergic reaction can occur. This means that for a person to experience an allergic reaction to a scorpion sting, they must have been stung previously.

However, it appears that some people have allergic reactions to their first scorpion sting. This means that there is another substance that is so similar to scorpion venom that the immune system treats both substances the same. This is termed "cross-reactivity." Studies performed by our research group found that the venom of the imported fire ant appears to have cross-reactivity with scorpion venom.

It appears that people with an allergy to the imported fire ant have the ability to develop allergic reactions from scorpion stings. These allergic reactions can even occur upon a person’s first sting by a scorpion.

How is Scorpion Allergy Treated?

Acute allergic reactions from scorpion stings are treated in much the same way as allergic reactions to insect stings. This may include the use of injectable epinephrine, antihistamines and oral or injectable corticosteroids to treat anaphylaxis.

Currently, there is no known cure for people with scorpion allergy, other than to avoid from being stung in the future.

However, given the cross-reactivity between scorpion and imported fire ant venom, it has been theorized that treatment with allergy shots using imported fire ant extract may prevent future allergic reactions to scorpion stings as well. However, more studies are needed before this can be recommended as a course of treatment. Pre-clinical research has also looked at the possibility of using toxin-specific nanobodies. This, as well, needs further research before a definitive treatment is available.

Want to keep learning? Find out more about stinging insect allergy.


Bouhaouala-Zahar, B., Ben Abderrazek, R., Hmila, I., Abidi, N., Muyldermans, S., and M El Ayeb. Immunologic Aspects of Scorpion Toxins: Current Status and Perspectives. Inflammation and Allergy and Drug Targets. 2011. 10(5):358-68.

Hmila, I., Cosyns, B., Tounsi, H. et al. Pre-Clinical Studies of Toxin-Specific Nanobodies: Evidence of In Vivo Efficacy to Prevent Fatal Disturbances Provoked by Scorpion Envenoming. Toxicology and Applied Pharmacology. 2012. 264(2):222-31.

More, D., Nugent, J., Hagan, L., Demain, J., Schwertner, J., Whisman, B., and T. Freeman. Identification of Allergens in the Venom of the Common Striped Scorpion. Annals of Allergies, Asthma, and Immunology. 20014. 93(5):493-8.

Nugent, J., More, D., Hagan, L., Demain, J., Whisman, B., and T. Freeman. Cross-Reactivity Between Allergens in the Venom of the Common Striped Scorpion and the Imported Fire Ant. Journal of Allergy and Clinical Immunology. 2004. 114(2):383-6.

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