Allergy Intolerance notes the Patient’s reaction to certain substances, this is very critical data and needs to be preserved throughout a patients profile.

This data is a bit complicated to store and maintain as the allergies can exist for a patient throughout their life, instances for allergies should be editable cross allergies and they should remain visible even after the encounter has ended, but only to the point in time data, this makes it really complicated.

In care, the proposed solution is,

when an allergy is edited in care under an encounter different to the original encounter, the allergy data will be converted into a point in time data and stored exclusively for the old encounter, this gives them access all the time.

Since we support multiple encounters at the same time, we also need to support de duplication.