Allergy

Authors: Flaherty, Alice W.; Rost, Natalia S.

Title: Massachusetts General Hospital Handbook of Neurology, The, 2nd Edition

Copyright 2007 Lippincott Williams & Wilkins

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Allergy

A. Rx of anaphylaxis

• Maintain airway: Consider intubation.

• Epinephrine:

  • Standard: 0.2-0.5 cc of 1:1,000 IM, or SQ 0.2-0.5 mg q5min.

  • Elderly or in shock: Dilute 0.1 cc of 1:1,000 in 10 cc NS; then give it IV over 5-10 min.

  • Stridor: Racemic epinephrine nebs.

• Oxygen: if slow response to epi or if underlying lung problems.

• IVF: 1-2 L NS initially.

• Diphenhydramine + ranitidine: IM 50 mg + IV 50 mg, respectively, over 5 minutes.

• Steroids: E.g., dexamethasone 10-40 mg IV.

B. Premedication to prevent iodinated contrast reaction

Use nonionic contrast. Give prednisone 50 mg PO 13, 7, and 1 h before; diphenhydramine 50 mg PO 1 h before (but evidence for this is not strong).