Anaphylaxis is characterized by the sudden onset of acute allergic symptoms involving two or more organ systems. An acute allergic emergency is a challenge for physicians due to its life-threatening potential. The incidence of anaphylactic reactions has increased in recent years. Most frequent elicitors of mast cell and primarily histamine dependent anaphylactic reactions are food, insect venom or drugs. Allergic reactions are graded into four groups according to the classification by Ring and Messmer; grade I is defined by the onset of cutaneous symptoms only whereas grade IV is characterized by cardiovascular shock as well as cardiac and/or respiratory arrest.
The treatment of allergic reactions should be guided by the severity of the reaction. Initially an intramuscular epinephrine injection into the lateral thigh should be given if cutaneous, mucosal and cardiovascular/respiratory symptoms occur. Additionally, the patient should receive intravenous antihistamines and corticosteroids. For self-treatment in the case of an allergic emergency, oral antihistamines and corticosteroids should be prescribed to the patient.