What is a common symptom of an anaphylactic transfusion reaction?

In anaphylactic transfusion reactions, symptoms often manifest rapidly and can include dyspnea (difficulty breathing) and cyanosis (a bluish discoloration of the skin due to low oxygen levels). This reaction is an immune response triggered by the recipient's antibodies reacting to the donor plasma proteins, leading to the release of mediators such as histamine. This results in bronchospasm, leading to respiratory distress and hypoxia, which is reflected in the dyspnea and cyanosis observed.

The other symptoms provided in the options, while they can occur in various transfusion reactions, are not characteristic of anaphylaxis specifically. For example, fever and chills are more commonly associated with febrile non-hemolytic transfusion reactions, hypotension and urticaria can also occur but are part of a broader range of allergic reactions rather than uniquely identifying anaphylaxis, and severe headache is not a typical symptom of transfusion reactions. Therefore, the combination of dyspnea and cyanosis distinctly highlights the respiratory implications of an anaphylactic response during a transfusion.