> ## Documentation Index
> Fetch the complete documentation index at: https://docs.metriport.com/llms.txt
> Use this file to discover all available pages before exploring further.

# AllergyIntolerance

> Risk of harmful or undesirable, physiological response which is unique to an individual and associated with exposure to a substance.

## Properties

| Name | Required | Type | Description |
| - | - | - | - |
| identifier | No | [Identifier](/medical-api/fhir/data-types/identifier)\[] | External ids for this item |
| clinicalStatus | No | [CodeableConcept](/medical-api/fhir/data-types/codeableconcept) | active / inactive / resolved |
| verificationStatus | No | [CodeableConcept](/medical-api/fhir/data-types/codeableconcept) | unconfirmed / confirmed / refuted / entered-in-error |
| type | No | code | allergy / intolerance - Underlying mechanism (if known) |
| category | No | code\[] | food / medication / environment / biologic |
| criticality | No | code | low / high / unable-to-assess |
| code | No | [CodeableConcept](/medical-api/fhir/data-types/codeableconcept) | Code that identifies the allergy or intolerance |
| patient | Yes | Reference\<[Patient](/medical-api/fhir/resources/patient)> | Who the sensitivity is for |
| encounter | No | Reference\<[Encounter](/medical-api/fhir/resources/encounter)> | Encounter when the allergy or intolerance was asserted |
| onset\[x] | No | dateTime, [Age](/medical-api/fhir/data-types/age), [Period](/medical-api/fhir/data-types/period), [Range](/medical-api/fhir/data-types/range), string | When allergy or intolerance was identified |
| recordedDate | No | dateTime | Date first version of the resource instance was recorded |
| recorder | No | Reference\<[Practitioner](/medical-api/fhir/resources/practitioner) / [PractitionerRole](/medical-api/fhir/resources/practitionerrole) / [Patient](/medical-api/fhir/resources/patient) / [RelatedPerson](/medical-api/fhir/resources/relatedperson)> | Who recorded the sensitivity |
| asserter | No | Reference\<[Patient](/medical-api/fhir/resources/patient) / [RelatedPerson](/medical-api/fhir/resources/relatedperson) / [Practitioner](/medical-api/fhir/resources/practitioner) / [PractitionerRole](/medical-api/fhir/resources/practitionerrole)> | Source of the information about the allergy |
| lastOccurrence | No | dateTime | Date(/time) of last known occurrence of a reaction |
| note | No | [Annotation](/medical-api/fhir/data-types/annotation)\[] | Additional text not captured in other fields |
| reaction | No | AllergyIntoleranceReaction | Adverse Reaction Events linked to exposure to substance |
| - id | No | string | Unique id for inter-element referencing |
| - extension | No | [Extension](/medical-api/fhir/data-types/extension)\[] | Additional content defined by implementations |
| - modifierExtension | No | [Extension](/medical-api/fhir/data-types/extension)\[] | Extensions that cannot be ignored even if unrecognized |
| - substance | No | [CodeableConcept](/medical-api/fhir/data-types/codeableconcept) | Specific substance or pharmaceutical product considered to be responsible for event |
| - manifestation | Yes | [CodeableConcept](/medical-api/fhir/data-types/codeableconcept)\[] | Clinical symptoms/signs associated with the Event |
| - description | No | string | Description of the event as a whole |
| - onset | No | dateTime | Date(/time) when manifestations showed |
| - severity | No | code | mild / moderate / severe (of event as a whole) |
| - exposureRoute | No | [CodeableConcept](/medical-api/fhir/data-types/codeableconcept) | How the subject was exposed to the substance |
| - note | No | [Annotation](/medical-api/fhir/data-types/annotation)\[] | Text about event not captured in other fields |

## Search Parameters

| Name | Type | Description | Expression |
| - | - | - | - |
| asserter | reference | Source of the information about the allergy | AllergyIntolerance.asserter |
| category | token | food / medication / environment / biologic | AllergyIntolerance.category |
| clinical-status | token | active / inactive / resolved | AllergyIntolerance.clinicalStatus |
| code | token | Code that identifies the allergy or intolerance | AllergyIntolerance.code |
| criticality | token | low / high / unable-to-assess | AllergyIntolerance.criticality |
| date | date | Date first version of the resource instance was recorded | AllergyIntolerance.recordedDate |
| identifier | token | External ids for this item | AllergyIntolerance.identifier |
| last-date | date | Date(/time) of last known occurrence of a reaction | AllergyIntolerance.lastOccurrence |
| manifestation | token | Clinical symptoms/signs associated with the Event | AllergyIntolerance.reaction.manifestation |
| onset | date | Date(/time) when manifestations showed | AllergyIntolerance.reaction.onset |
| patient | reference | Who the sensitivity is for | AllergyIntolerance.patient |
| recorder | reference | Who recorded the sensitivity | AllergyIntolerance.recorder |
| route | token | How the subject was exposed to the substance | AllergyIntolerance.reaction.exposureRoute |
| severity | token | mild / moderate / severe (of event as a whole) | AllergyIntolerance.reaction.severity |
| type | token | allergy / intolerance - Underlying mechanism (if known) | AllergyIntolerance.type |
| verification-status | token | unconfirmed / confirmed / refuted / entered-in-error | AllergyIntolerance.verificationStatus |

## Inherited Properties

| Name | Required | Type | Description |
| - | - | - | - |
| id | No | string | Logical id of this artifact |
| meta | No | [Meta](/medical-api/fhir/data-types/meta) | Metadata about the resource |
| implicitRules | No | uri | A set of rules under which this content was created |
| language | No | code | Language of the resource content |
| text | No | [Narrative](/medical-api/fhir/data-types/narrative) | Text summary of the resource, for human interpretation |
| contained | No | Resource\[] | Contained, inline Resources |
| extension | No | [Extension](/medical-api/fhir/data-types/extension)\[] | Additional content defined by implementations |
| modifierExtension | No | [Extension](/medical-api/fhir/data-types/extension)\[] | Extensions that cannot be ignored |

To view the FHIR specification for this resource, see [AllergyIntolerance](https://www.hl7.org/fhir/StructureDefinition/AllergyIntolerance).


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