Acute allergic reaction
Background
- Similar to Anaphylaxis but does not meet all the requirements (i.e. just skin manifestations)
Clinical Presentation
- Presentation can be delayed
Workup
- Clinical
Differential Diagnosis
Acute allergic reaction
- Allergic reaction/urticaria
- Anaphylaxis
- Angioedema
- Anxiety attack
- Asthma exacerbation
- Carcinoid syndrome
- Cold urticaria
- Contrast induced allergic reaction
- Scombroid
- Shock
- Transfusion reaction
Treatment
- Antihistamines for pruritus
- Ranitidine has been found to improve urticaria but not angioedema at 2 hours[1])
- Corticosteroids are of questionable efficacy
- Rule out Anaphylaxis
- Difficult to differentiate from Angioedema
Disposition
- Consider brief observation in the ED for improvement of symptoms
References
- ↑ Lin, RY et al. Improved Outcomes in Patients With Acute Allergic Syndromes Who Are Treated With Combined H1 and H2 Antagonists. Annals of Emergency Medicine. 36:5 NOVEMBER 2000.