Post by venomshock on Oct 5, 2009 23:42:56 GMT 11
Of the 1500 scorpion species, the vast majority are only capable of producing a local reaction similar in scope and effect to a bee sting. Only around 50 species are known to produce venom that causes serious systemic effects in humans. Of these 50 species, half (mostly in the family Buthidae) produce enough venom to pose a lethal risk to humans.
Still, severe reactions and death from stings are very common, accounting for thousands of deaths a year worldwide, 10 times as many as snake bites. Most of the deaths attributed to scorpion stings occur in children, the elderly and the infirm in rural, agricultural areas of Africa, South America and Mexico, where the most venomous species are ubiquitous.
Scorpions rarely aggressively attack humans, but will often reflexively strike when they are handled, stepped on, or accidentally crushed in clothing, or placed in other situations they detect as threatening. Their ubiquity in certain rural areas and nocturnal, cold-blooded physiology often result in scorpions making their day burrows in human objects or dwellings. Footwear or clothing left outside overnight, thatched roofs, cracks in plaster or concrete, and wood and brush piles are all common shelter sites for scorpions.
Among the most dangerous are the deathstalker (L. quinquestriatus) and the fat-tailed scorpion (Androctonus), bearing the most potent venom and the highest human death toll in the Scorpion order (respectively). Both are native to the deserts and grasslands of North Africa and the Middle East, and account for nearly 75% of the worldwide deaths attributed to scorpion stings every year. Although death may occur, envenomations from one of the 50 most potent species generally causes unpleasant and temporarily debilitating systemic effects such as vomiting, cramps, blurred and wobbly vision, sensitivity to light, hypersalivation, difficulty swallowing, and agitation.
Signs and Symptoms of Envenomation
Most of the scorpions stings (70% in one article) occurs on the hands. The rest mostly occur on the legs and stings on other region is rare.
Possible local effects are:
1) Pain at the site of sting. Some species causes unspeakable pain I heard. (100% victims of Tityus spp experience pain)
2) Itchiness. (usually masked by pain)
3) Slight to medium swelling
4) Slight bleeding (rare and most likely not related to toxin as only Heterometrus scaber seems to have hemolytic components)
As most scorpion venom is of neurotoxin type, systemic effect is more to be expected.
Early systemic effects includes:
1) Sweating
2) Pallor (paleness of skin)
3) Tachypnea ( fast breathing )
4) tachycardia (fast heart beat)
5) hypertension (heightened blood pressure)
6) salivation (uncontrolled saliva production) with frothy sputum
7) respiratory wheezing
8) stridor (high pitch respiration sound)
9) blurred vision
10)roving eye movement
11)oculogyric crisis (cannot control eye movement)
12)slurred speech
13)dysphagia (cannot swallow properly)
14)pharyngeal spasm (cannot control much of the mouth)
15)drowsiness
Many of the symptoms are sometimes due to or aggravated by victim's shock and anxiety. It is known that some victim shows these signs even when there's no venom injected! Such case is not uncommon and is mainly psychological. Nevertheless, medical attention should be given as injury from psychological distress is very REAL and likely. Even injecting just saline and reassurance gives prompt curative effect.
Advanced symptoms are:
1) muscle twitching (myoclonus?)
2) motor hyperactivity
3) incoordination (ataxia?)
4) increased muscle tone
5) Opisthotonos (spasm causing extreme hyperextension of body, bent over backwards)
6) over-sensitive or undersensitive muscle reflex
7) Seizure like symptoms
8) Chest pain
9) vomitting
10)gastric distension (feeling of fullness)
11)diarrhea
12)abdominal cramps
13)temperature dysregulation (abnormally high or low temperature)
14)pulmonary oedema
Though some symptoms can be psychological as well, prompt medical attention must be given at the above signs. The likelihood of serious envenomation is very high with such symptoms. Anaphylaxis may be a likely contributor as well
Late symptoms are:
1) Altered sensorium (changed sensory perception)
2) cyanosis (turns purple)
3) hypotension (low blood pressure)
4) bradycardia (slow heart rate)
5) incontinence (cannot control urine........)
6) seizure
7) respiratory and cardiac failure (dying....)
8) paresis - slight to complete paralysis (cannot move)
9) Altered Electrocardiograph (ECG for heart action potential)
10)coma
One can almost rule out pure pschological effect except in epilepsy prone victims. This definitely requires hospitalisation and may be more suitable for Intensive Care Unit (ICU). Anaphylaxis is still a likely potentiating factor.
Blood testing of envenomated patient gives-
1) increased serum and urine catecholamines (eg. adrenaline) and metabolites.
2) Leukocytosis (high leukoytes count; detoxification?)
3) hyperkalemia (high potassium in blood plasma; Na-K-ATPase pump?)
4) hyponatraemia (low sodium in blood plasma; Na-K ATPase pump?)
5) hyperglycaemia (high glucose; due to increased glucocorticoids?)
Dead victim are shown
1) to have diffuse internal bleeding (haemorrhage)
2) passive congestion
3) fatty necrosis
3) myocarditis.
Very rarely do one reach this stage...... It is avoidable in almost all cases if APPROPRIATE medical help is given.
These exotic pets are best pets for display not for "hands-on".[/u]
