Hymenoptera stings

(Redirected from Hymenoptera Stings)


  • All Hymenoptera share similar components in their venonm and patients can have allergies across the subgroups[1]
  • Most reactions are local but anaphylaxis and serum sickness are possible

Bees (Apids)

Stinging bee
  • Include Bumblebees and Honeybees
  • Barbed Stingers - remain in victims and the process of stinging kills the bee
  • Killer bees (hybridized African Bees) have small individual toxin potency but attack in large numbers with increased aggression[2]
  • Main allergen is phospholipase A2, hyaluronidase and melittin[1]
  • redness and irritation last 1-3 days

Wasps (Vespids)

  • Include Yellow Jackets, Hornets, and Wasps
  • Non barbed stinger - can sting multiple times and the sting does not cause the wasps' death
  • Histamine, phospholipase, antigen 5, and bradykinin similar to bees[1]
  • Redness and irritation last 1-3 days

Fire Ants (Formicidae)

Fire ants
  • Solenopsis invicta (red fire ant) and Solenopsis richteri (black fire ant)
  • Alkaloid venom
  • Intense burning papules that may turn to pustules in 24hrs
  • Localized necrosis has also been reported[3]

Clinical Features

Local Reaction

Local reaction: 2 minutes after bee sting
Local reaction: 6 minutes after bee sting (stinger removed)
Local reaction: 27 after bee sting
Local reaction: 1 day after bee sting
Local reaction: Fire ant bite
  • Urticarial lesion contiguous with sting site
  • Severe local reaction may involve one or more neighboring joints
  • Local reaction occurring in mouth or throat can produce airway obstruction
  • Local reaction occurring around eye can result in cataract, iris atrophy, globe perforation

Toxic Reaction

Anaphylactic reaction

  • Majority occur within first 15min; nearly all within 6hr
  • No correlation with number of stings
  • IgE mediated, rather than direct response to the venom.
  • Shorter the interval between sting and onset of symptoms the more severe the reaction

Delayed Reaction

  • May occur 5-14d after a sting
  • Serum sickness features (fever, malaise, urticaria, lymphadenopathy, polyarthritis)

Differential Diagnosis

Envenomations, bites and stings


  • Usually clinical


Local Reaction

  • Ice packs diminish swelling and delays absorption of venom
  • NSAIDs and antihistamines for comfort
  • Infection is uncommon, but may present as ongoing swelling or cellulitis

Systemic reaction


  • Normally outpatient, unless anaphylaxis or systemic toxicity
    • EpiPen should be prescribed on discharge if significant reaction
  • Admission/observation for victims with >100 stings, substantial comorbidities, those at extremes of age

See Also


  1. 1.0 1.1 1.2 King TP et al. Structure and biology of stinging insect venom allergens. Int Arch Allergy Immunol. 2000;123(2):99-106
  2. Díaz-Sánchez C. et al. Suvival after massive (>2000) Africanized Honey bee stings. Arch Intern Med. 1998;158(8):925-927
  3. Fernández-Meléndez S. et al. Anaphylaxis caused by imported red fire ant stings in Málaga, Spain. J Investig Allergol Immunol. 2007;17(1):48-49

Review Questions

You are seeing a patient who has been stung by a bee. The risk of his developing anaphylaxis depends most upon which of the following?

the size of the bee
the size of the bee’s stinger
the nature of the most severe previous reaction experienced by the patient
the amount of cutaneous erythema
whether the patient is on oral steroid treatment