What data point does the First Reaction column in AllergyFact table represent?

The First Reaction column in the AllergyFact table signifies the first recorded allergic reaction an individual experienced. This data point is critical for understanding a patient's allergy history and providing appropriate care. By documenting the initial reaction, healthcare providers can better assess the progression of allergies over time, identify patterns, and make informed decisions about avoidance strategies or treatments. It serves as a foundational element in the comprehensive allergenic profile of the individual, which is essential for effective patient management in clinical settings.