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that allows them to inflict multiple stings. Yellow jackets are carnivores that congregate around dead meat
or foodstuffs.
Fire ants typically bite and hold onto the victim with their mandibles and then swivel their abdomen in an arc
around the fixed mouthparts, inflicting multiple stings. The venom of most ants is less potent than that found
in flying Hymenoptera, causes much less tissue destruction and is much less likely to elicit a generalized
allergic reaction (about 80 anaphylactic deaths reported). The venom of fire ants is almost 95% alkaloid
and exerts a direct toxic effect on human and animal systems. A number of human deaths from the toxins
contained in multiple fire ant bites have been reported, especially in old and debilitated persons. However,
other individuals have been known to survive as many as 5,000 fire ant stings.
Subjective: Symptoms
Instantaneous stinging pain, warmth (vasodilation) and pruritus at site of sting(s), nausea and vomiting,
visceral pain following ingestion of insect and stings to the GI tract.
Objective: Signs
Local: Rapidly spreading edema (as large as 10-15cm) and urticaria near sting site; compromised distal
circulation from edema; stinging apparatus from bees and bleeding may be seen in the wound; distal sensory
loss if stung over peripheral nerve; corneal ulceration from corneal sting.
Generalized: Rapid onset of symptoms, urticaria, confluent red rash, shortness of breath, wheezing airway
(tongue, soft palate, etc.) edema, weakness, syncope, anxiety/confusion, chest pain, tachypnea, tachycardia,
hypotension, delirium, shock and cardiorespiratory arrest
Assessment:
Diagnose based on history of exposure and/or captured specimens.
Differential Diagnosis - angina (see Cardiac: Acute MI), rheumatoid arthritis (see Symptom: Joint Pain),
corneal abrasion/laceration (see Symptom: Eye Problems: Eye Injuries), snakebite (see Toxicology), cat
scratch disease (see ID: Bartonellosis); cellulitis; honey exposure in susceptible individual
Plan:
Treatment:
Anaphylactic or Generalized Toxic (Anaphylactoid) Reaction: see (Shock: Anaphylactic)
Single Sting from Flying Hymenoptera (bees, wasps, hornets, and yellowjackets):
- Remove stinger and venom sac intact as quickly as possible (stinging apparatus may actively injects
venom into the wound for one minute), regardless of method. - Apply ice or cold water for anesthesia and to control swelling.
- Apply local analgesic, antibacterial or steroid ointments as desired (see Symptom: Rash). Other
remedies to include ammonia, sodium bicarbonate, and papain (meat tenderizer) have minimal proven
effectiveness. - Elevate extremity to limit spread of edema.
Fire Ant Stings: - Do not unroof vesicles.
- Apply topical antibiotic and/or anesthetic creme for secondary infections (see Symptom: Rash). Use
prophylactic antibiotics for children with >30 fire ant stings. - NSAIDs may reduce the degree of inflammation; antihistamines may diminish itching but promote
somnolence, topical anesthetics, e.g., Dermoplast
Massive Multiple Stings: - Be prepared to treat for anaphylaxis or anaphylactoid reaction from venom load (see Shock:
Anaphylactic). - Do NOT use massive doses of parenteral steroids or antibiotics in individuals not having anaphylactic
or toxic reaction. - Give oral NSAIDs to reduce inflammation (see Symptom: Joint Pain) and antihistamines to reduce
pruritus (see Symptom: Pruritus/Itching). - Use topical hydrocortisone cream and topical anesthetics as needed (e.g., Dermoplast Spray =
benzocaine 20%/menthol 0.5%).