Anaphylaxis
[8] Diagnosis is based on the presenting symptoms and signs after exposure to a potential allergen or irritant and in some cases, reaction to physical exercise.
[6][1] The primary treatment of anaphylaxis is epinephrine injection into a muscle, intravenous fluids, then placing the person "in a reclining position with feet elevated to help restore normal blood flow".
[1] Carrying an epinephrine autoinjector, commonly called an "epipen", and identification regarding the condition is recommended in people with a history of anaphylaxis.
[15] The most common areas affected include: skin (80–90%), respiratory (70%), gastrointestinal (30–45%), heart and vasculature (10–45%), and central nervous system (10–15%)[16] with usually two or more being involved.
[3] Symptoms typically include generalized hives, itchiness, flushing, or swelling (angioedema) of the affected tissues.
[4] The wheezing is typically caused by spasms of the bronchial muscles[19] while stridor is related to upper airway obstruction secondary to swelling.
[3] Less common causes include: physical factors, biological agents such as semen, latex, hormonal changes, food additives and colors, and topical medications.
[18] Physical factors such as exercise (known as exercise-induced anaphylaxis) or temperature (either hot or cold) may also act as triggers through their direct effects on mast cells.
In Western cultures, ingestion of or exposure to peanuts, wheat, nuts, certain types of seafood like shellfish, milk, fruit and eggs are the most prevalent causes.
[3][16] Sesame is common in the Middle East, while rice and chickpeas are frequently encountered as sources of anaphylaxis in Asia.
[3] Some medications (vancomycin, morphine, x-ray contrast among others) cause anaphylaxis by directly triggering mast cell degranulation.
[32] Venom from stinging or biting insects such as Hymenoptera (ants, bees, and wasps) or Triatominae (kissing bugs) may cause anaphylaxis in susceptible people.
[37] People with atopic diseases such as asthma, eczema, or allergic rhinitis are at high risk of anaphylaxis from food, latex, and radiocontrast agents but not from injectable medications or stings.
[8] Interleukin (IL)–4 and IL-13 are cytokines important in the initial generation of antibody and inflammatory cell responses to anaphylaxis.
[3] When any one of the following three occurs within minutes or hours of exposure to an allergen there is a high likelihood of anaphylaxis:[3] Skin involvement may include: hives, itchiness or a swollen tongue among others.
[3] During an attack, blood tests for tryptase or histamine (released from mast cells) might be useful in diagnosing anaphylaxis due to insect stings or medications.
[20] Blood testing for specific IgE can be useful to confirm milk, egg, peanut, tree nut and fish allergies.
[20] Non-immune forms of anaphylaxis can only be determined by history or exposure to the allergen in question, and not by skin or blood testing.
[3] Asthma however typically does not entail itching or gastrointestinal symptoms, syncope presents with pallor rather than a rash, and a panic attack may have flushing but does not have hives.
[10] In a person who died from anaphylaxis, autopsy may show an "empty heart" attributed to reduced venous return from vasodilation and redistribution of intravascular volume from the central to the peripheral compartment.
Immunotherapy with Hymenoptera venoms is effective at desensitizing 80–90% of adults and 98% of children against allergies to bees, wasps, hornets, yellowjackets, and fire ants.
[3] Anaphylaxis is a medical emergency that may require resuscitation measures such as airway management, supplemental oxygen, large volumes of intravenous fluids, and close monitoring.
[46] A period of in-hospital observation for between 2 and 24 hours is recommended for people once they have returned to normal due to concerns of biphasic anaphylaxis.
[9][48] It is recommended that after diagnosis and treatment of anaphylaxis, the patient should be kept under observation in an appropriate clinical setting until symptoms have fully resolved.
[50][51] A 2007 Cochrane review did not find any good-quality studies upon which to base recommendations[51] and they are not believed to have an effect on airway edema or spasm.
The action plan usually includes use of epinephrine autoinjectors, the recommendation to wear a medical alert bracelet, and counseling on avoidance of triggers.
[60] In 1901, Albert I, Prince of Monaco requested Richet and Portier join him on a scientific expedition around the French coast of the Atlantic Ocean,[61] specifically to study on the toxin produced by cnidarians (like jellyfish and sea anemones).
[60] Richet and Portier boarded Albert's ship Princesse Alice II for ocean exploration to make collections of the marine animals.
[62] Richet and Portier extracted a toxin called hypnotoxin from their collection of jellyfish (but the real source was later identified as Portuguese man o' war)[63] and sea anemone (Actinia sulcata).
[68] Richet continued to study on the phenomenon and was eventually awarded the Nobel Prize in Physiology or Medicine for his work on anaphylaxis in 1913.
