Anaphylaxis is a medical emergency. Clinically, it is a dramatic presentation of the classic signs and symptoms: urticaria (hives), breathing problems (wheezing or laryngeal stridor), and in the severest cases, hypotension and syncope. Manifestations of anaphylaxis are often biphasic, i.e., early signs and symptoms resolve, only to recur several hours later. Even with early and appropriate treatment, reversing an anaphylactic reaction is not always possible.
The causes of anaphylaxis fall into three major categories: foods, drugs and insect stings. Foods constitute the most common etiology outside the hospital (where drugs and x-ray contrast media predominate). Peanuts and tree nuts head the food list and latex has now become important.
Death may follow an anaphylactic attack within minutes, or days to weeks. Late deaths are generally caused by organ damage that occurred early in the course of anaphylaxis.
The first step of acute management is the intramuscular (I.M.) or sub-cutaneous injection of aqueous epinephrine 1:000 (maximum dose 0.3 to 0.5 ml). A second dose may be necessary within 10 minutes if no improvement is seen.
Once epinephrine has been administered, other therapies are of benefit. Studies suggest that the combination of the antihistamine diphenhydramine (1 mg/kg, up to 75 mg) either IM or intravenously (IV) and a second antihistamine, cimetidine (4 mg/kg, up to 300 mg) administered IV may be more effective than either antihistamine alone. In a medical setting, oxygen and an IV line are started.
Long-term management should have prevention as its primary goal. This entails a thorough exposure history (drugs, foods, etc.) and sometimes skin testing or laboratory testing.
When the allergen cannot be avoided, other preventive measures should be considered, including venom immunotherapy (in all patients with proven Hymenoptera anaphylaxis), drug desensitization protocols (in patients with anaphylactic sensitivity to a necessary drug), and
Adams/SHA /Dec. '99/1 of 8/pg. 2 pretreatment protocols for patients with systemic reactions to x-ray contrast media.
(Beck S. Taking action against anaphylaxis. Contemporary Pediatrics 1999; 16(8):87-96)
COMMENT: Anaphylaxis usually is not difficult to recognize and prompt administration of epinephrine is usually lifesaving. Once the initial reaction is under control, finding its cause and instituting a strategy to prevent future episodes is of prime importance. Recent problems with Epi-PenŽ are of concern (poor potency and misadministration by students or adults). - R.A
Home Library/Research Links School Nurse Associations Our Publications Contact Us
