Anaphylactic

Anaphylactic (also known as anaphylaxis) is a severe, potentially life-threatening allergic reaction that can occur rapidly. It is a medical emergency that requires immediate treatment. Anaphylaxis can affect multiple organ systems, including the skin, respiratory system, gastrointestinal system, and cardiovascular system.

Causes

Anaphylaxis is typically triggered by exposure to an allergen. Common allergens include:

• Food allergens such as peanuts, tree nuts, shellfish, milk, and eggs.
• Insect stings from bees, wasps, and ants.
• Medications such as penicillin and other antibiotics, aspirin, and nonsteroidal anti-inflammatory drugs (NSAIDs).
• Latex.

Pathophysiology

Anaphylaxis occurs when the immune system overreacts to an allergen by releasing a flood of chemicals, including histamine, that can cause vasodilation, increased vascular permeability, and bronchoconstriction. This leads to symptoms such as hypotension, urticaria, angioedema, and bronchospasm.

Symptoms

Symptoms of anaphylaxis can vary but often include:

• Skin reactions such as hives, itching, and flushed or pale skin.
• Swelling of the face, eyes, lips, or throat.
• Constriction of the airways, leading to wheezing and trouble breathing.
• A weak and rapid pulse.
• Nausea, vomiting, or diarrhea.
• Dizziness or fainting.

Diagnosis

Anaphylaxis is primarily diagnosed based on clinical presentation and history of exposure to a known allergen. Laboratory tests may include measuring levels of tryptase and histamine in the blood.

Treatment

Immediate treatment of anaphylaxis involves:

• Administration of epinephrine (adrenaline) via an auto-injector.
• Calling emergency medical services.
• Additional treatments may include antihistamines, corticosteroids, and beta-agonists.

Prevention

Preventing anaphylaxis involves avoiding known allergens and carrying an epinephrine auto-injector for emergency use. Patients are also advised to wear a medical alert bracelet.

Prognosis

With prompt treatment, the prognosis for anaphylaxis is generally good. However, delayed treatment can lead to severe complications or death.

See also

• Allergy
• Immune system
• Histamine
• Epinephrine
• Auto-injector