A scorpion sting is an injury caused by the stinger of a
scorpion
Scorpions are predatory arachnids of the order Scorpiones. They have eight legs, and are easily recognized by a pair of grasping pincers and a narrow, segmented tail, often carried in a characteristic forward curve over the back and always end ...
resulting in the medical condition known as scorpionism, which may vary in severity. The anatomical part of the scorpion that delivers the sting is called a "
telson
The telson () is the posterior-most division of the body of an arthropod. Depending on the definition, the telson is either considered to be the final segment of the arthropod body, or an additional division that is not a true segment on accou ...
". In typical cases, scorpion stings usually result in pain,
paresthesia
Paresthesia is an abnormal sensation of the skin (tingling, pricking, chilling, burning, numbness) with no apparent physical cause. Paresthesia may be transient or chronic, and may have any of dozens of possible underlying causes. Paresthesias ar ...
, and variable swelling. In serious cases, scorpion stings may involve the
envenomation
Envenomation is the process by which venom is injected by the bite or sting of a venomous animal.
Many kinds of animals, including mammals (e.g., the northern short-tailed shrew, ''Blarina brevicauda''), reptiles (e.g., the king cobra), spider ...
of humans by toxic scorpions, which may result in extreme pain, serious illness, or even death depending on the toxicity of the venom.
Most scorpion stings range in severity from minor swelling to medically significant lesions, with only a few able to cause severe allergic, neurotic or necrotic reactions. However, scorpion stings account for approximately 3,000 deaths a year worldwide.
The Brazilian yellow scorpion (''
Tityus serrulatus'') is one species known for being especially dangerous, being responsible for most scorpion sting fatalities in
South America
South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the southe ...
.
Scorpion stings are seen all over the world but are predominantly seen in the tropical and subtropical areas. In the Western hemisphere, these areas include
Mexico
Mexico (Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guatema ...
, northern South America and southeast
Brazil
Brazil ( pt, Brasil; ), officially the Federative Republic of Brazil (Portuguese: ), is the largest country in both South America and Latin America. At and with over 217 million people, Brazil is the world's fifth-largest country by area ...
. In the Eastern hemisphere, these regions include
Sub-Saharan Africa
Sub-Saharan Africa is, geographically, the area and regions of the continent of Africa that lies south of the Sahara. These include West Africa, East Africa, Central Africa, and Southern Africa. Geopolitically, in addition to the List of sov ...
, the
Middle East
The Middle East ( ar, الشرق الأوسط, ISO 233: ) is a geopolitical region commonly encompassing Arabian Peninsula, Arabia (including the Arabian Peninsula and Bahrain), Anatolia, Asia Minor (Asian part of Turkey except Hatay Pro ...
, and the
Indian subcontinent
The Indian subcontinent is a list of the physiographic regions of the world, physiographical region in United Nations geoscheme for Asia#Southern Asia, Southern Asia. It is situated on the Indian Plate, projecting southwards into the Indian O ...
.
Characteristics and side effects
The byproducts of some arthropods may be used as an
aphrodisiac
An aphrodisiac is a substance that increases sexual desire, sexual attraction, sexual pleasure, or sexual behavior. Substances range from a variety of plants, spices, foods, and synthetic chemicals. Natural aphrodisiacs like cannabis or cocain ...
. Some of these arthropods whose byproduct may be used as medicines can be found in North America.
Across North America, the
Arizona bark scorpion
:''The striped bark scorpion and the closely related Baja California bark scorpion are also called bark scorpions.''
The Arizona bark scorpion (''Centruroides sculpturatus'', once included in ''Centruroides exilicauda'') is a small light brown s ...
(''Centruroides sculpturatus)'' has proven to be the most venomous scorpion. While stings from this species will rarely result in death, side effects can include numbness, tingling, convulsions, difficult breathing, and occasionally, paralysis. These side effects may last up to 72 hours after injection of the venom. It is also observed that penile erection may occur after being stung. The pain of a sting from the Arizona Bark Scorpion has been compared to being struck by a bolt of lightning or electrical current.
These symptoms may become visible 4 to 7 minutes after envenomation.
Envenomation of a human by a scorpion may affect the sympathetic or parasympathetic systems depending on the species of scorpion. Some of the more severe side effects include respiratory distress syndrome, pulmonary edema, cardiac dysfunction, impaired hemostasis, pancreatitis, and multiple organ failure. Additionally, treatment of the sting depends on the severity of the incident, which is classified as mild, moderate, or severe. This treatment is composed of three different aspects of the sting: symptomatic measures, vital functions support, and injection
antivenom
Antivenom, also known as antivenin, venom antiserum, and antivenom immunoglobulin, is a specific treatment for envenomation. It is composed of antibodies and used to treat certain venomous bites and stings. Antivenoms are recommended only if th ...
. Not all envenomations result in systemic complications; only a small proportion of stings have this effect on the victim.
Mechanism
The composition of scorpion venom consists of different compounds of varying concentrations. The compounds consist of neurotoxins, cardiotoxin, nephrotoxin, hemolytic toxic, phosphodiesterases, phospholipase, histamine,
serotonin
Serotonin () or 5-hydroxytryptamine (5-HT) is a monoamine neurotransmitter. Its biological function is complex and multifaceted, modulating mood, cognition, reward, learning, memory, and numerous physiological processes such as vomiting and vas ...
, etc. Of these different toxins, the most important and most potent one is the neurotoxin concentration. This compound has neuromuscular and neuroautonomic effects, as well as damages the surrounding local tissue.
Neurotoxin
Neurotoxins are toxins that are destructive to nerve tissue (causing neurotoxicity). Neurotoxins are an extensive class of exogenous chemical neurological insultsSpencer 2000 that can adversely affect function in both developing and mature ner ...
s work to change voltage-dependent sodium channels, resulting in prolonged neuronal and neuromuscular activity. This prolonged activity of sodium channels results in an erection. There may be nerve damage due to the stabilization of voltage-dependent sodium channels in the open conformation. This position leads to the prolonged and continuous firing of neurons in the somatic, sympathetic, and parasympathetic nervous systems. Continuous firing of neurons causes over excitation and prevents the transmission of normal nerve impulses down the axon.
The venom composition of the deathstalker scorpion contains neurotoxins which are almost completely responsible for this symptom. The poison from this scorpion contain 4 components:
chlorotoxin
Chlorotoxin is a 36-amino acid peptide found in the venom of the deathstalker scorpion (''Leiurus quinquestriatus'') which blocks small-conductance chloride channels. The fact that chlorotoxin binds preferentially to glioma cells has allowed the d ...
,
charybdotoxin
Charybdotoxin (CTX) is a 37 amino acid neurotoxin from the venom of the scorpion '' Leiurus quinquestriatus hebraeus'' (''deathstalker'') that blocks calcium-activated potassium channels. This blockade causes hyperexcitability of the nervous syst ...
,
scyllatoxin
Scyllatoxin (also leiurotoxin I) is a toxin, from the scorpion '' Leiurus quinquestriatus hebraeus'', which blocks small-conductance Ca2+-activated K+ channels. It is named after Scylla, a sea monster from Greek mythology. Charybdotoxin is also f ...
, and
agitoxin
Agitoxin is a toxin found in the venom of the scorpion '' Leiurus quinquestriatus hebraeus'' (yellow scorpion). Other toxins found in this species include charybdotoxin (CTX). CTX is a close homologue of Agitoxin.
Structure
Agitoxin can be p ...
s. Upon injection with the venom, sacral parasympathetic nerve are stimulated causing a change in the neuronal transmission in vascular and nonvascular smooth muscles. The compound known as the
vasoactive intestinal polypeptide
Vasoactive intestinal peptide, also known as vasoactive intestinal polypeptide or VIP, is a peptide hormone that is vasoactive in the intestine. VIP is a peptide of 28 amino acid residues that belongs to a glucagon/secretin superfamily, the ligan ...
(VIP) is the main transmitter. This polypeptide is realized from nerves found long the erectile tissue of the corpus calosum. VIP is the strongest relaxant of penile smooth muscle structure, resulting in an erection upon envenomation. This is the proposed mechanics for all scorpion of the family Buthidae, whose venom composition contains these compounds.
Epidemiology
Overview
Scorpions are nocturnal animals that typically live in deserts, mountains, caves, and under rocks. It is when they are disturbed that they attack. Scorpions that possess the ability to inject toxic venom with their sting belong to the family
Buthidae
The Buthidae are the largest family of scorpions, containing about 100 genera and 1339 species as of 2022. A few very large genera (''Ananteris'', ''Centruroides'', '' Compsobuthus'', or '' Tityus'') are known, but a high number of species-poor o ...
. The Middle East and North Africa are home to the deadliest scorpions, belonging to the genus ''
Buthus
''Buthus'' is a genus of scorpion belonging and being eponymous to the family Buthidae. It is distributed widely across northern Africa, including Morocco, Mauritania, Algeria, Tunisia, Libya, Egypt, Senegal, Guinea-Bissau, Nigeria, Sudan, Somali ...
'', ''
Leiurus
''Leiurus'' is a genus of scorpion of the family Buthidae. The most common species, ''L. quinquestriatus'', is also known under the common name Deathstalker. It is distributed widely across North Africa and the Middle East, including the western ...
'', ''
Androctonus
Fattail scorpion or fat-tailed scorpion is the common name given to scorpions of the genus ''Androctonus'', one of the most dangerous groups of scorpion species in the world.Hendrixson, B. E. 2006. Buthid scorpions of Saudi Arabia, with notes ...
'', and ''
Hottentotta
''Hottentotta'' is a genus of scorpions of the family Buthidae. It is distributed widely across Africa, except for most of the Sahara desert. Species in the genus also occur in the Middle East, the Arabian Peninsula, southeastern Turkey, Iraq, I ...
''. In South America, the deadliest scorpion belongs to genus ''
Tityus''. In India and Mexico, the deadliest scorpions involved in scorpionism are ''
Mesobuthus
''Mesobuthus'' is an Asian genus of scorpions in the family Buthidae
The Buthidae are the largest family of scorpions, containing about 100 genera and 1339 species as of 2022. A few very large genera (''Ananteris'', ''Centruroides'', '' Comps ...
'' and ''
Centruroides
''Centruroides'' is a genus of scorpions of the family Buthidae. Several North American species are known by the common vernacular name bark scorpion. Numerous species are extensively found throughout the southern United States, Mexico, Centra ...
'', respectively.
Weather, seasons, and climate
Scorpions are nocturnal arachnids that have shown a seasonal pattern that is also related to climate.
Specifically in Central America, scorpion attacks are mostly seen during the hot months of the year, noting that in Argentina this occurs in the months of October to April. Additionally, a rainy climate may also change the frequency of scorpion incidents. Lower levels of rainfall, specifically precipitation below 30 mm/month, can be associated with fewer scorpion stings, whereas rainfall greater than 30 mm/month shows no relationship to incident rate. This could be due to potentially disruptive effects of rainfall on scorpion habitat.
Central America
In Central America, most scorpion stings are mildly toxic to humans. However,
Panama
Panama ( , ; es, link=no, Panamá ), officially the Republic of Panama ( es, República de Panamá), is a transcontinental country spanning the southern part of North America and the northern part of South America. It is bordered by Cos ...
has reported an incidence of 52 cases per 100,000 people in 2007. Between 1998 and 2006, 28 people have died as result of scorpion stings. In Panama, the taxa of scorpions responsible for these deaths belong to the genus ''
Tityus.'' This scorpion species is also found in parts of northern South America. Historically, the presence of these scorpions in Panama could be due to the closure of the Panamanian isthmus, thus allowing for the migration of the scorpions from Panama into the northern part of South America.
''
Tityus pachyurus
''Tityus pachyurus'' is a species of arachnid endemic to Central America and South America.
Characteristics
''Tityus pachyurus'' can grow from 6 to 9 cm in length, its pedipalps are reddish, while the fourth and fifth segments of the post-abd ...
'' is among the most important scorpionist species. Envenomation by this scorpion is characterized by intense local pain, that usually does not result in tissue injury.
Scorpions possess venom glands located at the distal extremity of their abdomen. There are currently 1,400 known species of scorpions and each possesses venom glands. However, of these 1,400 species, only 25 are known to be dangerous enough to humans to potentially cause death upon envenomation.
Other countries in Central America are habitat to the scorpion genus ''
Centruroides
''Centruroides'' is a genus of scorpions of the family Buthidae. Several North American species are known by the common vernacular name bark scorpion. Numerous species are extensively found throughout the southern United States, Mexico, Centra ...
.'' Species in this genus are only mildly toxic to humans even though they have ion channel-active toxins in their venom.
References
{{Medical resources
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, ICD9 = {{ICD9, E905.2
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Physiology
Toxicology
Parasitic infestations, stings, and bites of the skin
Arthropod attacks
Scorpions and humans