What is the management for a pediatric patient with a history of allergies who has been stung by a wasp?

Management of Wasp Sting in a Pediatric Patient with Allergies

For a pediatric patient with a history of allergies who has been stung by a wasp, immediately assess the type of reaction and administer intramuscular epinephrine 0.01 mg/kg (maximum 0.3 mg) into the anterolateral thigh if any systemic symptoms are present, as epinephrine is the only first-line treatment for anaphylaxis. 1, 2, 3

Immediate Assessment and Stinger Removal

• Remove the stinger within 10-20 seconds by scraping or flicking it away with a fingernail—never grasp and pull the venom sac, as this forces more venom into tissue. 2
• Rapidly categorize the reaction type to guide treatment: local, large local, or systemic. 2

Treatment Algorithm Based on Reaction Type

Simple Local Reactions (mild swelling, redness, pain at sting site)

• Apply cold compresses or ice packs immediately to reduce local pain and swelling. 2
• Administer oral antihistamines to reduce itching and discomfort. 2
• Provide oral analgesics (acetaminophen or ibuprofen) for pain relief. 2

Large Local Reactions (extreme swelling extending beyond sting site, peaking at 48-72 hours)

• Initiate a short course of oral corticosteroids promptly within the first 24-48 hours to limit progression of swelling. 2
• Continue cold compresses and oral antihistamines as adjunctive therapy. 2
• These reactions are allergic in nature and occur in up to 25% of the population. 4

Systemic Reactions/Anaphylaxis (urticaria, angioedema, bronchospasm, hypotension, laryngeal edema)

• Administer intramuscular epinephrine 0.01 mg/kg (maximum 0.3 mg in children) into the anterolateral thigh immediately—this is the ONLY first-line treatment. 1, 2, 3
• Epinephrine has no contraindication in life-threatening anaphylaxis, even in patients with cardiovascular disease. 1
• Repeat dosing may be required for persistent or recurrent symptoms. 1
• Antihistamines and corticosteroids are NOT substitutes for epinephrine. 1
• Signs of anaphylaxis include flushing, syncope, tachycardia, hypotension, bronchospasm, laryngeal edema, urticaria, angioedema, and gastrointestinal symptoms. 3

Post-Acute Management for All Patients with Systemic Reactions

• Prescribe an epinephrine autoinjector and train caregivers on proper use and indications for emergency self-administration. 1, 2
• Refer to an allergist-immunologist for venom-specific IgE testing (skin testing preferred over in vitro assays) and consideration of venom immunotherapy (VIT). 1, 2
• Educate caregivers on insect avoidance measures: avoid brightly colored clothing, flowery prints, strongly scented materials, walking barefoot outdoors, and areas near bushes, eaves, and garbage containers. 1
• Consider medical identification bracelet or necklace for stinging insect hypersensitivity. 1

Special Considerations for Pediatric Patients

Venom Immunotherapy Decision-Making

• VIT is generally NOT necessary in children ≤16 years who have experienced isolated cutaneous systemic reactions (urticaria/angioedema only) without other systemic manifestations. 1
• VIT IS recommended for children who experienced respiratory symptoms (bronchospasm, laryngeal edema) or cardiovascular symptoms (hypotension, shock, loss of consciousness). 1
• VIT reduces the risk of subsequent systemic reactions to less than 5% and is extremely effective. 1

Timing of Allergy Testing

• Skin testing or in vitro IgE testing should ideally be performed at least 6 weeks after the sting reaction, as both may be temporarily non-reactive in the first few weeks. 1
• However, if rapid initiation of VIT is required for severe reactions, testing without waiting may be necessary. 1
• If initial testing is negative despite convincing history of anaphylaxis (especially with upper airway obstruction or hypotension), consider repeat skin testing or in vitro testing before concluding immunotherapy is not indicated. 1

Critical Pitfalls to Avoid

• Never delay epinephrine administration in favor of antihistamines or corticosteroids—epinephrine is the only first-line treatment for anaphylaxis. 1, 2
• Do not assume a child with "just allergies" will only have mild reactions—systemic reactions occur in 0.4% to 0.8% of children and can be life-threatening. 1
• Be aware that toxic reactions can occur with massive envenomation (typically >100 stings) even without allergy, causing multi-organ dysfunction. 1, 2
• Rare neurologic complications (quadriparesis, neuritis) have been reported and may respond to corticosteroids. 5
• Patients taking β-blockers or with underlying mastocytosis are at higher risk for severe reactions and may require more aggressive management. 1