Scorpion Sting in children

2. INTRODUCTION
• Scorpion envenomation is considered a major public health problem
allover the world particularly in developing countries as Iraq.
• More than 1.2 million scorpion stings occur annually worldwide,
particularly in tropical and subtropical regions resulting in 3250
deaths.
• For every person killed by a venomous snake, 10 are killed by a
venomous scorpion.

3. Epidemiology
• Epidemiological studies on scorpion sting and diversity have been
conducted in several countries in the Middle East such as Turkey,
Saudi Arabia and Iran.
• Recent unofficial reports from Iraqi Ministry of Health indicate many
cases of scorpion envenoming, which vary according to region,
climate, and environmental conditions.
• Few studies have addressed scorpion diversity and the precise
numbers of cases.

4. Epidemiology
• Age: Adults, especially those of workforce age, are stung more
often than children.
• However, children are more likely to develop a more rapid
progression of symptoms after a scorpion sting, with increased
severity and higher mortality because of their lower body
weight, with a global rate of 10 deaths per 1000 cases in
children.
• Gender: Females may be more susceptible than males to the
same amount of scorpion venom because of their lower body
weight.
• Climate: The scorpion activity is highly temperature dependent.
Therefore, the highest rate of scorpion stings are reported in summer
with the highest proportion of stings occurring in July.

5. Etiology:
• A scorpion has a flattened elongated body and can easily hide
in cracks.
• It has 4 pairs of legs, a pair of claws, and a segmented tail that
has a venomous spike at the end.
• There are 1500 subspecies of scorpions worldwide, with 50
subspecies having venom dangerous for humans with Scorpion
(Buthidae) families are the most toxic offender.

6. Etiology
• The species collected in Iraq were all members of two families
(Scorpionidae and Buthidae).
• Scorpionidae: Scorpio maurus,
• Buthidae : Androctonus crassicauda, Hottentotta saulcyi were
identified & Hottentotta mesopotamicus also has been reported.

7. Scorpionidae Family
• In Iraq, the Scorpionidae family is represented by a single genus and
species, Scorpio maurus.
• The pentagonal sternum and absence of an accessory spine on the telson
are considered major morphological features of the Scorpionidae family.
• Scorpio maurus has yellowish brown appearance.
• It is considered non-hazardous to humans & it is not considered medically
important.
• Its the most frequently recorded species due to their preference to inhabit
at high altitude regions ranged between 900m to 1200m. (55%) of
scorpions .

8. Buthidae Family
• Buthidae is the largest of all scorpion families and includes most of
the medically important scorpions.
• Scorpions from this family can cause severe envenomation which is
sometimes lethal to the elderly and children
• The triangular sternum together with the presence of accessory
spines on telson is the main prominent characteristic of this family

9. Androctonus crassicauda
• Androctonus crassicauda is black in color and has a wide, thickly
segmented tail.
• Man-Killer fat-tailed scorpion
• The median lethal dose: 0.08-0.5 mg/kg
• A. crassicauda generally prefers low altitude localities and has been
collected previously in the middle and southern part of Iraq
• This species inhabits under cemetery stones, inside sand and soil in plain.
• However it was found in a higher place at attitude range from 600m to
900m in northern part of Iraq.
• It is one of the widely distributed species in Iraq.

10. Hottentotta salucyi
• Hottentotta saulcyi are yellow in color with a black tail end.
• H. saulcyi were captured accounting for 33% of all scorpions
captured.
• H. saulcyi is distributed widely in northern region of Iraq and inhabits
in calcareous soil.
• The specimens were collected in a mountain region at elevation
between 650m to 1000 m.

11. PATHOPHYSIOLOGY AND CLINICAL FEATURES
• Scorpions use their pincers to grasp their prey; then, they arch
their tail over their body to drive their stinger into the prey to
inject their venom, sometimes more than once.
• The scorpion can voluntarily regulate how much venom to inject
with each sting; which is usually 0.1-0.6 mg.

12. Scorpion venom
• Scorpion venom: water soluble, antigenic, complex structure
composed of several toxins ; cardipotoxins, nephrotoxins, hemolytic
toxins, and neurotoxins and incorporate a mixture of Enzymes;
phosphodiesterases, phospholipases, hyaluronidases &
compound substances; glycosaminoglycans, histamine,
serotonin, tryptophan, and cytokine.
• Also contain: salts, acidic proteins, and organic compounds.

13. • Generally, the venom is distributed locally and rapidly into the
tissue if it is deposited into a venous structure.
• Venom deposited via the intravenous route can cause
symptoms only 4-7 minutes after the injection, with a peak
tissue concentration in 30 minutes and an overall toxin
elimination half-life of 4.2-13.4 hours through the urine.
• The more rapidly the venom enters the bloodstream, the higher
the venom concentration in the blood and the more rapid the
onset of systemic symptoms.
PATHOPHYSIOLOGY AND CLINICAL FEATURES

14. Clinical manifestations:
• Clinical manifestations of scorpion sting depend on
• Age, gender, weight, Health of the victim(comorbidities)
• Time of envenomation (season of sting ), Nature of the incident,
Number of stings, Site of envenomation.
• The duration to progress to systemic symptoms ranges from 5
minutes to 4 hours after the sting.
• The symptoms generally persist for 10-48 hours.

15. Signs & Symptoms
• Clinical manifestations range from minor local tenderness to
multisystem failure followed by death.
• Local symptoms: Pain, redness & swelling.
• Nonlethal scorpion species tend to produce local reactions
similar to a hymenopteran sting,

16. • Neurologic signs:
• release of catecholamines from the adrenal glands
(sympathetic nerves) or the release of acetylcholine from
postganglionic parasympathetic neurons.
• Scorpion venom after sting causes autonomic storm.
• Initially parasympathetic system is stimulated leading to excess
sweating, cold extremity, salivation, vomiting, and defecation due to
hyperperistalsis and priapism in male child.
• There is bradycardia at this stage and child may be irritable and
anxious.

17. • Parasympathetic phase usually last for 1–2 hours and gradually gives
way to sympathetic overdrive.
• Both alpha (α) and beta (β) activity is stimulated.
• α-stimulation is more predominant giving rise to peripheral
vasoconstriction and increase after load while β-stimulation causing
tachycardia and increased contractility.
• End effect is increased cardiac workload leading to cardiac failure,
pulmonary edema, arrhythmias, and death.
• Sympathetic overtone progress may occur in initial 6–12 hours.

18. • Cranial nerve effects include the following:
• Classic roving or rotary eye movements, blurred vision, tongue
fasciculations, and loss of pharyngeal muscle control may be
observed.
• Difficulty swallowing combined with excessive salivary
secretions may lead to respiratory difficulty.
• Somatic effects include the following:
• Restlessness and involuntary muscle jerking that can be
mistaken for seizures have been described.

19. • Seizures , Cerebral infarction, cerebral thrombosis, and acute
hypertensive encephalopathy have been described with a
variety of Buthidae scorpion envenomations.
• A person who has been stung by a scorpion usually has four
signs, with the most common being mydriasis, nystagmus,
hypersalivation, dysphagia, and restlessness.

20. • Cardiovascular signs occurs secondary to sympathetic &
parasympathetic neurons and also toxin induced myocarditis
biventricular dysfunction and profuse loss of fluids from
sweating, vomiting, diarrhea, and hypersalivation.
• Gastrointestinal signs: excessive salivation, Dysphagia is
possible.
• Nausea and vomiting: due to serotonin content of venom and
transient para sympathetic stimulation after sting.

21. • Respiratory signs: This is secondary to a direct toxin-induced
increased pulmonary vessel permeability effect and is also
secondary to catecholamine-induced effects of hypoxia and
intracellular calcium accumulation.
• Genitourinary signs: Patients have decreased renal plasma
flow, Toxin-induced acute tubular necrosis, Rhabdomyolysis; all
these may lead to renal failure.
• Priapism may occur secondary to cholinergic stimulation.

22. • Hematological signs: Platelet aggregation may occur because
of catecholamine stimulation.
• Disseminated intravascular coagulation with massive
hemorrhage may result from venom-induced defibrination.
• Allergic signs and serum sickness.

23. • Metabolic signs:
• Venom acts on cell membranes producing changes on the trans-
membrane action potential and permeability changes in calcium
and potassium channels altering the release of neurotransmitters
such as acetylcholine.
• One of the main metabolic changes produced by scorpion stings is
hyperkalemia.
• hypokalemia, Hypocalcemia and hyponatremia have been reported.
• Hyperglycemia may occur from catecholamine-induced hepatic
glycogenolysis, Toxic hepatitis, pancreatitis, and insulin inhibition.
• Patients may have an electrolyte imbalance and dehydration from
hypersalivation, vomiting, diaphoresis, and diarrhea.

24. Abroug’s classification
• Abroug’s classification for grading Signs and Symptoms of scorpion
sting cases
oGrade I: Pain and/or paresthesia at the scorpion sting site, tingling,
numbness and minor swelling in the skin area encompassing the sting
(local symptoms).
oGrade II: Fever, chills, tremor, excessive sweating, nausea, vomiting,
diarrhea, hypertension and priapism (systemic symptoms ± local
sympotoms)
oGrade III: Cardiovascular, respiratory, and/or neurologic distresses
(complications)

25. Laboratory Studies & Imaging Studies
• CBC count
• RFT & Electrolyte evaluation
• LFT & Coagulation parameters
• Glucose levels
• Troponin
• Creatine kinase
• amylase/lipase
• arterial blood gas (ABG)
• catecholamine, aldosterone, renin angiotensin, and antidiuretic
hormone levels.
• chest x-ray & ECG & Echocardiography.

26. Treatment & Management:
• Androctonus australis Hector Hospitalization Score is as
follows (total ≥2 = Hospitalization) :
• Priapism: +3
• Vomiting: +2
• SBP >160: +2
• Corticosteroid PTA: +2
• Temperature >38ºC: +1
• Heart rate >100 bpm: +1

27. Local treatment
• 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.
• Then hot water immersion: is as effective as ice pack
treatment in relieving pain.
• Immobilize the affected part in a functional position below the
level of the heart to delay venom absorption.
• Calm the patient to lower the heart rate and blood pressure,
thus limiting the spread of the venom.

28. Local treatment
• Apply a topical or local anesthetic agent to the wound to
decrease paresthesia.
• Nonsteroidal anti-inflammatory drugs (NSAIDs)
• Administer local wound care.
• Administer tetanus prophylaxis.(adults and children older than 7
years.
• Administer systemic antibiotics if signs of secondary infection
occur.

29. Systemic treatment
• Establish airway, breathing, and circulation (ie, ABCs) to provide
adequate airway, ventilation, and perfusion.
• Monitor vital signs (eg, pulse oximetry; heart rate, blood pressure,
and respiratory rate monitor).
• Supportive treatment with intravenous (IV) fluids to correct dehydration.
• oxygen if patient is hypoxic or tachypneic should be started.
• Patient developing pulmonary edema or cardiac failure may need
ventilatory support.

30. • After confirming clinical signs of envenomation, pharmacological
antidote, i.e. prazosin should be given.
• Prazosin still remains pharmacological gold standard of treatment.
• Prazosin is a pharmacological and physiological antidote to scorpion
venom actions.
• Dose: Administered orally in a dose of 250 to 500 μg/Kg in children
and 500 to 1000 μg/kg in adults and should be repeated every 3
hourly until the signs of clinical improvement.
• Dose is 40 µg/kg first dose followed by 20 µg/kg 3–4 hourly for next
12–24 hours while monitoring the clinical progress of patient.

31. prazosin
• A competitive post synaptic α-1 adrenergic receptor antagonist,
• it reduces preload, left ventricular impedance without causing
tachycardia.
• It reverses the metabolic syndrome evoked due to excessive
catecholamines release.
• It also inhibits sympathetic outflow in CNS.
• It inhibits phosphodiesterase, thereby enhancing cGMP level which is
one of the mediators of nitric oxide synthesis.
• It enhances insulin secretion which is inhibited by venom.
• Thus, its pharmacological properties can antagonise the
haemodynamic, hormonal and metabolic effects of scorpion venom.

33. • If patient presents in early hypertensive phase, systemic
(oral/sublingual) nifedipine can be tried to reduce blood pressure
immediately, but one should carefully rule out impending or
established cardiac failure before giving nifedipine since it is a
negative inotropic drug (calcium channel blocker) and can aggravate
congestive cardiac failure (CCF).
• If patient presents in severe vasoconstriction phase with CCF, potent
vasodilators like sodium nitroprusside (SNP) or nitroglycerine (NTG)
infusion can be given in infusion.

34. • Impending cardiac failure can be treated with dobutamine or
phosphodiesterase inhibitor like milrinone infusion (0.25–0.75
µg/kg/min).
• Evidence of significant cardiac injury with ischemia and arrhythmias;
can be treated with lidocaine, Mexiletine, amiodarone &
Nitroglycerine.
• Pulmonary edema: furosemide.
• shock or hypotension: Dobutamine: 5–15 µg/kg/min or Dopamine:
3–5 µg/kg/min.

35. • Administer barbiturates(Pentobarbital and/or a
benzodiazepine(Midazolam) continuous infusion for severe
excessive motor activity.
• For severe muscle spasms, administer muscle relaxants (ie,
benzodiazepines.)
• In some cases, be aware that morphine may potentiate the
venom.
• Also, the concurrent use of barbiturates and narcotics may add
to the respiratory depression in patients who have been
envenomated.

36. • Administer atropine to counter venom-induced
parasympathomimetic effects.
• The use of steroids to decrease shock and edema is of
unproven benefit.
• Antihistamines: Cimetidine (H2 antagonist) &
Diphenhydramine is used for the symptomatic relief of allergic.
• A vaccine preparation was tried in experimental animals but
was not pursued because of the need to prepare different
antigens according to different geographical areas and to
different species of scorpions living in the same area.

37. Antivenom:
• Antivenom is the treatment of choice after stabilization and
supportive care.
• These agents are composed of venom-specific F(ab’)2
fragments of immunoglobulin G (IgG) that bind and neutralize
venom toxins, facilitating redistribution away from target tissues
and elimination from the body.
• correct scorpion species identification is a prerequisite for
proper antivenom treatment.
• For scorpion antivenom, the exact dosing has not been
established so the quantity to be used is determined by the
patient’s clinical severity, symptom evolution, and treatment
response.

38. • General time guidelines for the disappearance of symptoms
after antivenom administration are as follows:
• Centruroides antivenom: Severe neurologic symptoms
reverse in 15-30 min. Mild-to-moderate neurologic symptoms
reverse in 45-90 min.
• Non-Centruroides antivenom: In the first hour, local pain
abates. In 6-12 hours, agitation, sweating, and hyperglycemia
abate. In 6-24 hours, cardiorespiratory symptoms abate.

39. • many physicians recommended it in grade III and grade IV
envenomations.
• Adverse effects included immediate and delayed
hypersensitivity reactions.
• The best result occurs when antivenin is administered as early
as possible (preferably within the first 2 h after the sting)
and with adequate quantities to neutralize the venom .
• It is given as 30 mL (three vials) first dose and to be repeated after 2–
4 hours later depending upon response.
Antivenom:

40. Prognosis
• Prognosis is dependent on many factors, including species of
scorpion, patient health, and access to medical care.
• Most patients recover fully after scorpion envenomation.
• Symptoms generally persist for 10-48 hours.
• If the victim survives the first few hours without severe
cardiorespiratory or neurologic symptoms, the prognosis is
usually good.
• Furthermore, surviving the first 24 hours after a scorpion sting
also carries a good prognosis.

41. • In children, the following factors were associated with a higher
mortality: metabolic acidosis, tachypnea, myocarditis,
pulmonary edema, encephalopathy, and priapism.
• The mode of death is usually via respiratory failure secondary
to anaphylaxis, bronchoconstriction, bronchorrhea, pharyngeal
secretions, and/or diaphragmatic paralysis, even though
venom-induced multiorgan failure may play a large role.
• Important thing should be mentioned; “nonlethal” species can
cause anaphylaxis ( be careful).
Prognosis

43. THANKS FOR YOUR
ATTENTION