How should I manage a patient presenting with a bee sting who has itching and flushing?

Management of Bee Sting with Itching and Flushing

Administer intramuscular epinephrine 0.3–0.5 mg immediately into the anterolateral thigh for this patient presenting with systemic allergic symptoms (itching and flushing beyond the sting site). 1, 2

Immediate Assessment and Treatment

Recognize this as a systemic reaction requiring epinephrine. Itching and flushing that extend beyond the local sting site indicate systemic involvement, even without respiratory or cardiovascular symptoms yet. 1, 2 Facial swelling or widespread urticaria confirms systemic allergic reaction. 2

First-Line Therapy: Epinephrine

• Give 0.3–0.5 mg intramuscular epinephrine in adults (0.01 mg/kg up to 0.3 mg in children) into the anterolateral thigh, not the arm or subcutaneous tissue. 1, 2
• Intramuscular thigh injection achieves faster and higher plasma concentrations than subcutaneous or arm routes. 1, 2
• Be prepared to repeat the dose in 10–20 minutes if symptoms persist, worsen, or recur. 1, 2
• Delayed epinephrine administration is associated with fatal outcomes—do not hesitate. 3, 1, 2
• No absolute contraindication exists even in patients with hypertension, cardiac disease, or those taking β-blockers; the risk of untreated anaphylaxis outweighs cardiac concerns. 1, 2

Adjunctive Measures (After Epinephrine)

• Place the patient recumbent with legs elevated if any hypotension develops. 2
• Administer oral antihistamines (cetirizine preferred for fastest onset) to reduce itching, but understand these have minimal immediate effect on life-threatening symptoms. 1, 2, 4
• Consider oral corticosteroids (e.g., prednisolone 50 mg) to prevent biphasic reactions, though they provide no immediate benefit. 2, 4
• Antihistamines and corticosteroids are NOT substitutes for epinephrine—they are adjuncts only. 1, 4

Observation Period

• Monitor for 4–12 hours depending on severity, as biphasic reactions (recurrence without re-exposure) can occur. 5, 6, 7
• Biphasic reactions are more common with initial hypotension or airway obstruction, and rarely occur without these features. 6

Discharge Planning and Long-Term Management

Prescribe Emergency Medication

• Prescribe an epinephrine autoinjector (300 µg for adults, 150 µg for children 15–30 kg) for lifelong carry-by use before discharge. 1, 2, 4
• Provide structured training on proper autoinjector technique, indications for use, and when to activate emergency services. 1, 2

Specialist Referral

• Refer to an allergist-immunologist for venom-specific IgE testing (skin testing or in vitro assay) and evaluation for venom immunotherapy (VIT). 3, 1, 2
• VIT is indicated for adults with any systemic reaction beyond isolated cutaneous signs and reduces future systemic reaction risk to <5%. 3, 1
• VIT duration is typically 3–5 years, with 80–90% remaining reaction-free after discontinuation. 1
• Extended or indefinite VIT is advised for patients with severe anaphylaxis history involving shock or loss of consciousness. 1

Patient Education

• Recommend a medical identification bracelet or necklace indicating insect sting allergy. 3, 1
• Educate on insect avoidance strategies: have nests removed by professionals, avoid bright clothing and flowery prints, wear protective clothing outdoors, avoid walking barefoot, and exercise caution near bushes and garbage areas. 3, 1, 2

Critical Pitfalls to Avoid

• Do not delay epinephrine while administering antihistamines or corticosteroids—epinephrine is first-line. 1, 2, 4
• Do not mistake systemic flushing for a simple local reaction—any symptoms beyond the sting site indicate systemic involvement. 1, 2
• Do not prescribe antibiotics unless clear secondary bacterial infection is present; early swelling is allergic inflammation, not infection. 1, 4
• Do not use subcutaneous epinephrine or arm injection—intramuscular thigh administration is superior. 1, 2

Special Medication Considerations

• β-blockers increase the risk of severe anaphylaxis and may reduce epinephrine effectiveness; discontinue when feasible, but do not withhold epinephrine if anaphylaxis occurs. 1
• ACE inhibitors are associated with higher severe anaphylaxis risk (odds ratio ~2.27); consider alternative antihypertensives when appropriate. 1