Treatment of Hymenopteran Stings

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Treatment ofHymenopteran Stings

• Matthew Tucker, D.O.
• Department of Emergency Medicine
• Hillcrest Medical Center
• Tulsa, OK

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Distribution and Biologyof Hymenopterans

• Order Hymenoptera represents the most developed
  form in class Insecta with regard to biology and
  behavior.
• One form or another is present in almost every
  environment on the planet.
• Their medical importance is underscored as they
  are responsible for the majority of venom related
  deaths in the US and Europe.

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Stinging Apparatus

• Evolved from ovipositor to defensive tool in some
  species.

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Medically Important Hymenoptera

• The order hymenoptera includes three families of
  medical importance
• Vespidae (wasps)- include the yellow jackets,
  hornets, and red wasps.
• Apidae (bees)- honey bees and bumble bees
• Fomicidae (stinging ants)- include the fire
  ants

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• Honey bee

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• Yellow jacket

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• Paper wasp

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Clinical Toxicology

• Introduction
• The winged members of hymenoptera generally cause
  the most medical issues, though the fire ant
  (Solenopsis) may cause severe reactions
• Typically the amount of venom injected is low,
  most people are stung many times over their life
  thus causing a potential sensitization to venom
  components resulting in severe reactions to
  future stings.
• The earliest description of an insect sting
  fatality was found in the tomb of the Egyptian
  pharaoh Menes who died in 2621 BC.

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Clinical Toxicology

• Composition of wasp and bee venoms
• Low molecular weight substances
• Histamine- pain inducer, dilatation and
  permeability of capillaries at the sting site,
  urticaria, angioedema, and hypotension.
• Dopamine
• Tyramine
• Epi and norepinephrine

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Clinical Toxicology

• Venom composition (cont)
• Peptides
• Various kinin-like peptides- associated with mast
  cell degranulation, responsible for most local
  effects .
• In bee venom, melittin is the peptide most
  associated with pain. Melittin breaks down the
  resting potential of the cell, thereby initiating
  the sensation of pain.

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Clinical Toxicology

• Venom composition (cont)
• High molecular weight substances
• Phospholipases A2 and B
• Hyaluronidases (venom spreading component)
• DNAse
• Others

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Clinical Aspects

• The various enzymes and vasoactive components
  induce a local inflammation in the region of the
  sting. If the sting is vascular, the venom can
  become systemic giving rise to more severe
  reactions.
• Patients with allergies to hymenoptera venom,
  only minute amounts of the allergen can initiate
  severe reactions.
• Systemic reactions are thought to be mediated by
  Ig-E.

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Clinical Aspects

• Reactions
• Local reaction occurs when there is swelling
  contiguous with the sting site. No systemic
  signs or symptoms exist.

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Clinical Aspects

• Reactions
• -Toxic reaction usually with history of 10 or
  more stings. The symptoms resemble systemic
  reactions, however there is no bronchospasm or
  urticaria. Typically, GI symptoms predominant
  . May also include HA, fever, muscle spasms,
  etc.

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Clinical Aspects

• Reactions
• Systemic reaction may occur with single or
  multiple stings and may be mild to severe.
  Symptoms may include cough, urticaria, and
  flushing. They may progress to wheezing, GI sx,
  N/V, laryngeal stridor, syncope, shock, and
  bloody sputum. This may be fatal in as little as
  30 min.

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Clinical Aspects

• Delayed reaction -presents as a serum-sickness
  type of reaction. Includes fever, malaise, HA,
  polyarthralgias occurring 10-14 days after the
  sting.

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Treatment

• If stinger is still present (honeybee), scrape it
  out, do not squeeze.
• Local reactions may be treated with ice packs,
  OTC analgesics and antihistamines. For more
  significant swelling, prednisone (20 40mg
  daily)
• Systemic reactions may present as a rapidly
  changing clinical picture.

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Treatment

• Systemic
• Monitoring and ALS measures early.
• If the clinical picture indicates, rapid
  administration of epinephrine (11000) 0.3 mL SQ
  (0.01mL/kg for children) is necessary.
• Diphenhydramine 50 100mg IM/IV for urticaria
  and pruritis.
• Nebulized albuterol for bronchospasm. Nebulized
  racemic epinephrine may be needed for
  laryngospasm.
• IV Solucortef or Solumedrol

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Treatment

• Systemic
• Airway should be monitored closely and control
  should be gained early if necessary.
• Crystalloid infusion for hypotension should be
  aggressive. If hypotension persists after fluid
  replacement, dopamine may be started.
• IV hydrocortisone or methylprednisolone may help
  prevent delayed symptoms.

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Prophylaxis and Long Term Management

• Skin testing and immunotherapy
• Personal rescue kits Ana-Kit or Epi-Pen
• Medic alert bracelets

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• Sources
• Tintinalli, J., Emergency Medicine A
  Comprehensive Study Guide, 3rd Ed.
• Meier J. and White J., Handbook of Clinical
  Toxicology of Animal Venoms and Poisons.

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• Thank you.