An insect that has an elongated body and a segmented, curved tail tipped with a venomous stinger.
A sting can be fatal to a person who is allergic to it.
The toxicity of scorpion venom varies by species. A given species' venom may contain many chemicals, some toxic to insects, others toxic to mammals.
Scorpion species with smaller and more slender claws generally have more toxic venom.
Scorpion stings are much more dangerous for infants and small children.
2. SCORPION VENOM
An insect that has
elongated body
a segmented,
curved tail tipped
with a venomous
stinger.
A sting can be fatal
to a person who is
allergic to it.
The toxicity of scorpion
venom varies by species. A
given species' venom may
contain many chemicals,
some toxic to insects,
toxic to mammals.
Scorpion species
with smaller and
more slender claws
generally have
toxic venom.
Scorpion stings are
much more
dangerous for
infants and small
children.
3. PATHOPHYSIOLOGY
oGrade 1: Local pain and paresthesias at the
sting site. The puncture wound may not be
noticeable in this grade. The "tap test" may
confirm a provider's suspicion by distracting the
patient and tapping on the area of the sting,
causing increased pain. This does not occur
other species. Care is limited to analgesia.
oGrade 2: Local pain and paresthesias at the
sting site as well as proximally. Recommended
care again includes analgesia with optional
When serious symptoms do occur, they are usually due to the Centruroides
species. Because of this, a classification scale has been created to grade each
envenomation by a Centruroides scorpion.
4. PATHOPHYSIOLOGY
o Grade 3: Grade 2 with added cranial nerve (increased oral secretions,
blurry vision, rapid tongue movement, nystagmus) or skeletal
neuromuscular dysfunction (flailing of the extremities and tetanus-like
arching of the back). These patients require analgesia and anxiolytics as
well as antivenom.
o Grade 4: Unlike grade 3 envenomations where the patient will
experience either cranial nerve or skeletal muscle dysfunction, grade 4
envenomations include both. This can cause hyperthermia,
rhabdomyolysis, pulmonary edema, and multiple organ failures.
antivenom is critical in this situation.
5. SIGNS AND SYMPTOMS
• Signs and symptoms at the site of the sting
may include:
– Pain, which can be intense
– Numbness and tingling in the area
the sting
– Slight swelling in the area around the
Most scorpion stings cause only localized signs and
symptoms, such as pain and warmth at the site of the sting.
Sometimes these symptoms may be quite intense, even if you
don't see redness or swelling.
6. SIGNS AND SYMPTOMS
• Signs and symptoms related to widespread (systemic) venom effects usually
occur in children who are stung and may include:
– Difficulty breathing
– Muscle twitching or thrashing
– Unusual head, neck and eye movements
– Drooling
– Sweating
– Nausea and vomiting
– High blood pressure (hypertension)
– Accelerated heart rate (tachycardia) or irregular heart beat (arrhythmia)
– Restlessness or excitability or inconsolable crying (in children)
7. HISTORY AND PHYSICAL EXAMINATION
• Most scorpion stings cause a local inflammatory reaction and pain.
• When the venom affects the sodium channels, this may manifest as
seizure-like activity in the patient and obscure the clinical picture,
especially when the child or infant is unable to relay an accurate history.
• Intubation may be required in these patients, as motor hyperactivity of
the pharyngeal muscles and uncontrolled diaphragmatic and intercostal
neuromuscular activity may be seen.
• These symptoms may progress quickly, causing impending airway
collapse.
• In the select species causing cardiopulmonary effects, tachycardia,
pulmonary edema, and more importantly, cardiogenic shock may be
seen.
• While uncommon, local tissue necrosis in days to weeks after the initial
8. TREATMENT
moving the patient away from the
scorpion
stabilizing the patient's airway and
vital signs
administration of antivenin
institution of symptomatic and local
treatment.
9. LOCAL TREATMENT
Calm the patient
• to lower the heart rate and blood pressure, thus limiting the spread of the venom.
Use ice bags
• to reduce pain and to slow the absorption of venom via vasoconstriction.
• This is most effective during the first 2 hours following the sting.
Administer local wound care.
Apply a topical or local anesthetic agent to the wound to decrease
paresthesia
Administer muscle relaxants for severe muscle spasms
Administer tetanus prophylaxis
Administer systemic antibiotics if signs of secondary infection occur.
10. LOCAL TREATMENTapplying a lymphatic-venous compression wrap 1 inch proximal to the
sting site
• For medical delay of secondary infection
• to reduce superficial venous and lymphatic flow of the venom but not to stop the
arterial flow.
• Only remove this wrap when the provider is ready to administer systemic support.
Immobilize the affected part in a functional position below the level of the
heart
11. SYSTEMIC TREATMENT
Establish airway, breathing, and circulation (ie, ABCs)
Monitor vital signs
Use invasive monitoring for patients who are unstable and
hemodynamic.
Administer oxygen.
Administer intravenous fluids to help prevent hypovolemia
Perform intubation and institute mechanical ventilation
Administer atropine to counter venom-induced
parasympathomimetic effects.
12. SYSTEMIC TREATMENT
HYPERDYNAMIC CARDIOVASCULAR CHANGES
administration of a combination of beta-blockers with sympathetic alpha-
blockers is most effective in reversing this venom-induced effect.
• Avoid using beta-blockers alone because this leads to an unopposed alpha-adrenergic
effect.
nitrates can be used for hypertension and myocardial ischemia.
diuretic may be used for pulmonary edema in the absence of hypovolemia
• afterload reducer, such as prazosin, nifedipine, nitroprusside, hydralazine, or
angiotensin-converting enzyme inhibitors, is better.Inotropic medications, such as digitalis, have little effect, while dopamine
aggravates the myocardial damage through catecholamine-like actions.
pressor such as norepinephrine to correct hypotension refractory to fluid
therapy.