Scorpion stings: symptoms, first aid and when to act

Scorpions are eight-legged arachnids with claws at the front and a flexible tail ending in a stinger. Cleveland Clinic says the tail holds two venom glands, and that a scorpion usually stings when it is surprised or threatened. Scorpions live in warm, dry climates around the world and often shelter under rocks, in firewood and in the crevices of houses.

Research cited by the same source suggests around 1.5 million stings happen worldwide each year. Because UK-based sources on scorpion stings are scarce, this guide draws mainly on United States medical references and on the NHS guidance for insect bites and stings. Species, antivenom availability and local emergency numbers differ abroad, so local advice matters when you are travelling.

Most stings cause local symptoms only. Cleveland Clinic describes redness, slight swelling and a mild tingling, burning or stinging sensation. The MSD Manual describes immediate pain and sometimes numbness or tingling over the involved part, with minimal swelling and possibly some tenderness and warmth around the wound.

Doctors sometimes use a tap test: tapping over the sting site makes the pain worse.

Rarely, venom affects the nervous system. Cleveland Clinic lists numbness all over the body, difficulty breathing or swallowing, a thick tongue with drooling, slurred speech, restlessness, seizures, roving eye movements, muscle twitching, an irregular heartbeat, high blood pressure and abdominal pain as reasons to go to hospital.

The MSD Manual says serious symptoms are most common in children and include restlessness, muscle spasms, abnormal and random head, neck and eye movements, agitation, drooling and sweating. In adults it describes fast heart rate, high blood pressure, faster breathing, weakness and muscle twitching as more prominent. Young children may be inconsolable, so any child who is unusually restless or distressed after a sting should be assessed urgently.

For a mild sting, Cleveland Clinic suggests cleaning the site with soap and water, applying ice or a cold compress, raising the area to heart level, using an antihistamine or corticosteroid on the skin, and taking an over-the-counter pain reliever. The NHS, writing about insect stings generally, advises an ice pack wrapped in a cloth for at least 20 minutes, keeping a swollen area raised, and not scratching.

The American Red Cross says tourniquets, cutting the wound, suction, ice used to slow venom, and electricity are myths that do not slow the spread of venom and are likely to cause pain and injury. It also notes that it is very difficult to tell dangerous from harmless scorpions, so if you are unsure which scorpion stung you or if symptoms spread beyond the sting site, seek medical care.

• Move away from the scorpion and keep calm.

• Wash the area with soap and water.

• Cool the area with a wrapped ice pack or a cold compress.

• Do not cut, suck or tie a tight band around the limb.

• Seek help early for a young child, an older adult, or anyone with symptoms beyond the sting site.

Treatment depends on the species and how much venom was injected. The MSD Manual says non-venomous stings are treated by symptoms, with ice and anti-inflammatory painkillers, while venomous stings may need bed rest, medicines for muscle spasm, and drugs given into a vein to control blood pressure, agitation and pain. Tetanus prevention should be considered as with any wound.

Antivenom exists for some species. The MSD Manual says a Centruroides-specific antivenom is available in the United States and should be given to patients with severe symptoms, particularly children, and Cleveland Clinic says antivenom should be given as soon as possible after serious symptoms appear.

For scorpions in parts of the world where venom is more toxic, such as Turkey, the Middle East and India, the MSD Manual notes that antivenoms for specific venoms are sometimes used in very severe cases. The MSD Manual's patient version adds that antivenom can itself cause a serious allergic reaction.

The NHS says to call 999 for swelling of the lips, mouth, throat or tongue, severe breathing difficulty, a tight throat, blue, grey or pale skin, sudden confusion, drowsiness or fainting after a sting, as these may signal a serious allergic reaction. It advises asking for an urgent GP appointment or calling NHS 111 if symptoms get worse or are not improving, if a person was stung in the mouth, throat or near the eyes, or has tummy pain and is being sick.

See a pharmacist if the area is hot, red, swollen, painful or oozing pus, which the NHS says can be a sign that a sting is infected.

If you are stung abroad by a scorpion you cannot identify, go to the nearest medical facility rather than waiting to see how it develops, and follow local emergency advice.

Cleveland Clinic advises wearing long sleeves, trousers, gloves and protective footwear in scorpion country, shaking out shoes and clothing before putting them on, taking care when moving logs, lifting rocks or collecting firewood, never handling scorpions with bare hands, and avoiding sleeping directly on the ground when camping. Scorpions are more active at night, though stings can happen at any time.