http://hl7.org/fhir/StructureDefinition/allergyintolerance-abatement|5.2.0

The date or estimated date that the allergy or intolerance resolved. This is called abatement because of the many overloaded connotations associated with resolution.
typedestination
baseDefinitionhttp://hl7.org/fhir/StructureDefinition/Extension
typehttp://hl7.org/fhir/StructureDefinition/Extension
Extension.value[x].typehttp://hl7.org/fhir/StructureDefinition/dateTime
Extension.value[x].typehttp://hl7.org/fhir/StructureDefinition/Age
Extension.value[x].typehttp://hl7.org/fhir/StructureDefinition/Period
Extension.value[x].typehttp://hl7.org/fhir/StructureDefinition/Range
Extension.value[x].typehttp://hl7.org/fhir/StructureDefinition/string