Management of Urticaria and Itching During Streptokinase Infusion in STEMI
Immediately slow or temporarily stop the streptokinase infusion and administer intravenous antihistamines and corticosteroids to manage the allergic reaction; if symptoms resolve, the infusion may be cautiously resumed at a slower rate with close monitoring, but if severe hypersensitivity or anaphylaxis develops, discontinue streptokinase permanently and consider alternative reperfusion strategies.
Immediate Assessment and Action
Assess the severity of the reaction:
- Mild reaction (isolated urticaria/itching without hemodynamic compromise): Temporarily slow or pause the streptokinase infusion 1, 2
- Severe reaction (hypotension, bronchospasm, angioedema, or anaphylaxis): Immediately discontinue streptokinase and initiate anaphylaxis management 3, 1
The distinction is critical because streptokinase is highly antigenic and can trigger IgE-mediated anaphylactic reactions, though these occur rarely 1, 2. Hypersensitivity reactions including urticaria have been documented with streptokinase use 3.
Management of Mild Allergic Reactions
For isolated urticaria and itching without hemodynamic instability:
- Slow the infusion rate from the standard 1.5 million units over 60 minutes to a more gradual administration 4
- Administer intravenous antihistamines (e.g., diphenhydramine 25-50 mg IV) immediately 1
- Consider intravenous corticosteroids (e.g., hydrocortisone 100-200 mg IV or methylprednisolone 125 mg IV) 3, 1
- Monitor vital signs continuously, particularly blood pressure, as streptokinase-induced hypotension is common (occurring in 20-40% of patients) and may be difficult to distinguish from anaphylaxis 5
If symptoms improve or resolve:
- Resume streptokinase infusion at a slower rate with continued close monitoring 1
- Maintain antihistamine coverage throughout the remainder of the infusion 1
Management of Severe Hypersensitivity/Anaphylaxis
If the patient develops signs of anaphylaxis (hypotension, bronchospasm, laryngeal edema, or rapidly spreading rash):
- Immediately discontinue streptokinase 3, 1
- Administer epinephrine 0.3-0.5 mg intramuscularly (1:1000 solution); this is the agent of choice for anaphylaxis-associated hypotension and may succeed when vasopressors like dopamine and norepinephrine fail 1
- Give intravenous corticosteroids (hydrocortisone 200 mg IV or methylprednisolone 125 mg IV) 3, 1
- Administer intravenous antihistamines (diphenhydramine 50 mg IV and H2-blocker like ranitidine 50 mg IV) 3, 1
- Provide aggressive fluid resuscitation for hypotension 1
- Secure airway if needed, as fatal cases of hemorrhage associated with traumatic intubation have been reported in patients receiving thrombolytics 3
- Monitor for several hours after symptom resolution, as angioedema has been observed up to 2 hours after infusion 3
Alternative Reperfusion Strategies
If streptokinase must be discontinued:
- Do NOT re-administer streptokinase if it was stopped due to allergic reaction, as the patient is now sensitized and at high risk for severe anaphylaxis 4
- Consider fibrin-specific agents (tenecteplase, alteplase, or reteplase) as alternatives, which are non-antigenic and preferred when available 4
- Arrange urgent transfer for rescue PCI if fibrinolysis fails or is contraindicated, as this is indicated for hemodynamic instability or worsening ischemia 4
- Continue adjunctive therapy with aspirin, clopidogrel, and anticoagulation regardless of thrombolytic choice 4
Important Caveats
Streptokinase-specific considerations:
- Streptokinase is absolutely contraindicated within 6 months of previous exposure due to high risk of serious allergic reaction from pre-existing antibodies 4
- The antigenicity of streptokinase distinguishes it from fibrin-specific agents, which do not carry this risk 4
- Routine pretreatment with corticosteroids and antihistamines is not supported by evidence and should not be standard practice 1
Distinguish hypersensitivity from streptokinase-induced hypotension: