Scorpion stings T63.2

The scorpions (Scorpiones) are a worldwide order of arachnids (Arachnida). About 2,350 species are known. Scorpions reach body sizes between 0.9 cm (Typhlochactas mitchelli) and 21 cm (Pandinus imperator and Hadogenes troglodytes the emperor scorpions). In America, their range extends from southern Canada to southern South America. In Europe they are found with a northern distribution as far as the south of Austria and Switzerland. However, the main focus of scorpion colonization is in tropical and subtropical regions. The greatest biodiversity is found in the Mexican desert areas. Scorpions are traditionally considered to thrive in dry habitats, but many species depend on high humidity. Scorpions are predominantly nocturnal. They feed on insects or arachnids, more rarely on snails or small vertebrates such as rodents, snakes and lizards. The body of scorpions is divided into a front body (Prosoma) and a clearly divided rear body (Opisthosoma). The opisthosoma consists of a broad part, the mesosoma, and a tail-like extended metasoma. This metasoma carries the telson (terminal spine and venomous bladder). Larger prey is killed with a stab through the terminal spine.

Most species are soil living and are divided into 4 basic types:

• Psammophilic scorpions: are adapted to sandy habitats. They are very mobile.
• Lithophilic scorpions: prefer to live in rocky habitats. They are usually flat, so that they can move easily between rocks.
• Digging Scorpions: they live mainly underground in self-digging caves. They only leave them for hunting and reproduction.
• Migrating scorpions: change their habitat.

After snake bites and bee and wasp stings, scorpion stings cause the most cases of illness from animal venoms worldwide. In Mexico, 20 352 people died from scorpion stings within twelve years (Schmidt G 1993). Most at risk are young children and persons weakened by age or disease. In Central Europe, there are no scorpions whose stings could be life-threatening to humans. Most of the dangerous species belong to non-European species. Contrary to the presumed dangerousness of scorpion stings, most scorpion stings only cause pain. This usually begins immediately after the sting and reaches the maximum pain after about 5 minutes. The intensity of pain in harmless species reaches about that of a wasp sting. In the (American) dangerous species, it reaches strong to most severe intensity and may last for days. They then require clinical monitoring.

In very rare cases, true allergic reactions (type I allergy) to the scorpion venom can be life-threatening even in these harmless species, corresponding to bee sting allergy. Therapeutically, external wound disinfection with alcohol and cooling compresses are recommended. Verification of sufficient tetanus protection. Further medical supervision is not necessary.

Scorpions from the genus Bothriururs spp. which occur in South America, v. Brazil, Chile and Argentina, and the North African and Near Eastern Buthus species, especially Buthus tunetanus cause severe local pain as well as systemic reactions. Tachycardia and hypertension, extrasystoles, and in severe cases later hypotension and shock symptoms are to be expected. In severe courses, hyperthermia to over 41°C, as well as hypothermia, may occur (Junghanss Th et al 1996). Several polyvalent antisera exist as specific antidotes, but their efficacy is controversial (Gueron M et al (1992).

The most dangerous scorpions cause not only life-threatening cardiovascular symptoms via released catecholamines, but states of agitation, confusion, and seizures. In the genus Centruroides, extrapyramidal symptoms with oropharyngeal dyskinesia and involuntary limb movements are also expected. Whenever a sting is suspected, the patient must be monitored by a physician for the first few hours; if there are no symptoms during this time, the condition is not expected to worsen. The cardiovascular problems are to be treated purely symptomatically (Gueron M et al. 1990). Against the neurological symptoms there are antisera for Centruroides spp. and Tityus spp. that work well (Curry SC et al. 1983).

Of the dangerous scorpions of North Africa and the Near East, Buthacus spp., the genus Hottentotta spp. and, most importantly, Androctonus spp. and Leiurus quinquestriatus belong to this group (Dehesa-Davila M et al. 1995). Furthermore Parabuthus spp. (South Africa to Black Sea coast), Mesobuthus spp. with M. tamulus (India), Centruroides spp. (Central America to southern USA) and the genus Tityus with 100 species.

Local therapy: After each scorpion sting disinfection of the wound. Surgical measures such as incision, excision (except for hemiscorpius-lepturus stings) and all other manipulations are contraindicated.

Prophylactic antibiotic administration is not recommended. Attention must be paid to intact tetanus protection.

In case of severe pain immobilisation of the affected limb. Bandaging of the affected limb is not indicated. Systemic: Paracetamol - Ibuprofen, possibly opiates.

In case of a rarely occurring allergic reaction (even with harmless scorpions), the measures for the different stages of allergic reactions have to be observed.

As a rough way of distinguishing between harmless and potentially dangerous scorpions, the "tail-scissor ratio" can be used. If the two claws ("scissors") of the scorpion are each wider ("stronger") than the tail with the poison sting, it can be assumed that the species cannot cause any significant symptoms in humans. However, if the tail is just as strong or the claws are even narrower than the tail, then it is possibly a poisonous specimen.

Basically, the following applies to scorpions: If you have strong scissors, you are not dependent on the poison.

General guidelines to avoid scorpion stings:

• Find out if there are any scorpions in the area.
• Scorpions only sting people when they are in distress or attacked.
• Do not turn over stones or large branches lying on the ground during the day.
• Do not feel out unclear rock crevices.
• Do not lay your clothes on the ground at night when camping.
• Inspect your shoes in the morning before putting them on and shake them off.
• Do not walk barefoot at night in desert regions.
• Do not sit on the bare ground.
• In any case, refrain from catching a scorpion.

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