
Anaphylaxis is an acute, potentially deathly reaction of over-sensitivity created by releasing the mediators from mast cells, basophils and other inflammatory cells.
Anaphylaxis is defined as multiple symptoms and signs, sole or in combination, which manifest within several minutes up to several hours, after the exposition to the provoking agent.
It can be mild, moderately severe to severe, or severe. In majority of the cases it is mild, but any anaphylaxis can potentially become deadly.
Anaphylaxis develops rapidly, usually from 5 to 30 minutes, and rarely is it the case of it lasting up to a few days. Sometimes there is a period of inaction from 1 to 8 hours, before a secondary reaction is developed (biphasic response). It can come to a deadly outcome within minutes, and rarely within days or weeks after the initial anaphylactic reaction.
The term anaphylaxis is usually reserved for immune, especially IgE mediated reaction.
The other term non-allergic anaphylaxis describes clinically identical reaction which is not immune mediated. Clinical diagnosis and treatment, are, after all, the same.
Clinical symptoms and signs:
The first manifestation of anaphylaxis can be fainting. Symptoms and signs can be manifested by one organ or a number of systems.
Causes of anaphylaxis, incurred by IgE mediated reaction, are most frequently: over-sensitivity to food, pollen, antibiotics and other medications, insects, latex, other proteins, as well as medical procedures (immune therapy).
Anaphylaxis demands urgent treatment:
ABC can also be used mnemonic for anaphylactic pharmacotherapy:
Epinephrine is an optional medicine of anaphylaxis. Common dose of epinephrine for adults is 0.3-0.5 mg of 1:1000 solution and is applied intramuscularly every 10-20 minutes or when necessary.
Antihistamines are not used as initial anaphylaxis therapy, but can be used when the patient is stabilized. It can be applied intravenous, intramuscularly or orally.
Corticosteroids are not important with acute anaphylaxis, but they can prevent relapse or extended anaphylaxis. Hydrocortisone (100 to 200 mg) or equivalent can be applied every 6-8 hours in the first 24 hours.
Epinephrine is an optional medicine for anaphylaxis treatment. Persons with high risk should have pre-prepared epinephrine injection in the self-aid kit. They must also be trained to apply it.