What is the first sign of anaphylaxis?

ANAPHYLAXIS typically begins with CUTANEOUS (skin) manifestations as the FIRST signs: HIVES (urticaria), flushing, and pruritus. These occur within minutes of exposure. This is followed by respiratory symptoms (bronchospasm, dyspnea — B), then cardiovascular collapse (hypotension, tachycardia). Eye edema can occur but is not typically listed as the 'first' sign. The skin manifestations (hives/urticaria) are classically the earliest and most common presenting sign (~90% of anaphylaxis cases). A is correct.