Recreational drug use are caused by an excessive response of the body to allergens, such as the pollen released by grasses and trees. An allergic reaction causes release of histamine by the body. Other uses of antihistamines are to help with normal symptoms of insect stings even if there is no allergic reaction. Their recreational appeal exists mainly due to their anticholinergic properties, that induce anxiolysis and, in some cases such as diphenhydramine, chlorpheniramine, and orphenadrine, a characteristic euphoria at moderate doses. High dosages taken to induce recreational drug effects may lead to overdoses. Antihistamines are also consumed in combination with alcohol, particularly
Allergic transfusion reaction Allergic transfusion reaction An allergic transfusion reaction is a blood transfusion that results in allergic reaction. It is among the most common transfusion reactions to occur. Reported rates depend on the degree of active surveillance versus passing reporting to the blood bank. Overall, they are estimated to complicate up to 3% of all transfusions. The incidence of allergic transfusion reactions is associated with the amount of plasma in the product. More than 90% of these reactions occur during transfusion. Allergic reactions from blood transfusion may occur from the presence of allergy-causing antigens within the donor's blood, or transfusion of antibodies