AllergyIntolerance

The following topic describes information for the AllergyIntolerance resource.

To interact with the REST endpoints in the AllergyIntolerance resource, see AllergyIntolerance.

Overview

The AllergyIntolerance resource provides the clinical assessment of a patient's allergy or intolerance when exposed to a specific substance, or class of substance, including information about the adverse reaction. Substances include, but are not limited to, medications, foods, environment (such as plants and animals), and insect bites. The allergy or intolerance list exists as a patient safety tool for clinical decision support when ordering medications and nutrition or guiding clinical treatments. This resource does not include adverse reactions or adverse events that are expected for the circumstance, such as an overdose or drug-drug interaction, or an error in the clinical process. References to implicitRules and modifierExtensions are not supported and fail a create or update request.

No Known Allergies (NKA) and No Known Medication Allergies (NKMA) are conveyed with predefined codes while Not Asked is conveyed through the absence of information (empty query response). Consumers can supply the negation codes (No known allergy (situation))(716186003) or No Known Medication Allergies (409137002) as long as the patient's profile contains no other active allergies. If the patient's profile has other active allergies and the consumer tries to add one of the codes above, the service returns an exception.

If NKA, NKMA, or both exist on the patient's allergy profile and a new allergy is added, the NKA and NKMA statuses are canceled.

If the consumer sends information that is deemed a duplicate (codified or free text), the service updates the existing allergy or reaction rather than adding a duplicate allergy or reaction.

With a patient safety or decision support use case, a consumer should avoid querying by status. The status field is not required and can ignore any entered-in-error allergies or intolerances.

This resource supports the following HL7 FHIR US Core Implementation Guide STU 4.0.0 profile:

• US Core AllergyIntolerance Profile

The following fields are returned if valued:

• AllergyIntolerance ID

• Clinical Status

• Verification Status

• Allergy Type

• Category (medication, food, environment)

• Criticality/potential harm

• Allergy Code

• Patient with allergy/intolerance

• Encounter

• Date of allergy onset

  • Precision Extension (for more information, see the Extensions section of this topic)

• Date/Time recorded

• Who recorded

  • Reference (Practitioner)

• Who reported

  • Reference (Patient)

  • Supports contained reference to PractitionerRole and RelatedPerson

• Comment

  • Annotation

• author

  • Reference (Practitioner)

• text (markdown)

• Adverse reaction (clinical symptoms/manifestation)

• Adverse reaction (severity)

Terminology Bindings

• AllergyIntolerance.clinicalStatus

  Description: The clinical status of the allergy or intolerance.

  Details: AllergyIntolerance Clinical Status Codes

  System: http://terminology.hl7.org/CodeSystem/allergyintolerance-clinical

• AllergyIntolerance.verificationStatus

  Description: The assertion about the certainty associated with the propensity, or potential risk, of a reaction to the identified substance (including pharmaceutical products).

  Details: AllergyIntolerance Verification Status Codes

  System: http://terminology.hl7.org/CodeSystem/allergyintolerance-verification

• AllergyIntolerance.type

  Description: The identification of the underlying physiological mechanism for the reaction risk.

  Details: AllergyIntoleranceType

  System: http://hl7.org/fhir/allergy-intolerance-type

• AllergyIntolerance.category

  Description: The category of the identified substance.

  Details: AllergyIntoleranceCategory

  System: http://hl7.org/fhir/allergy-intolerance-category

• AllergyIntolerance.criticality

  Description: The estimate of the potential clinical harm, or seriousness, of the reaction to the identified substance.

  Details: AllergyIntoleranceCriticality

  System: http://hl7.org/fhir/allergy-intolerance-criticality

• AllergyIntolerance.code

  Description: The code for an allergy or intolerance statement (either a positive or a negated or excluded statement). This code may be for a substance or pharmaceutical product that is considered responsible for the adverse reaction risk (for example, Latex), an allergy or intolerance condition (for example, Latex allergy), or a negated or excluded code for a specific substance or class (for example, No latex allergy) or a general or categorical negated statement (for example, No known allergy, No known drug allergies).

  • Details: RxNorm

    System: http://www.nlm.nih.gov/research/umls/rxnorm

  • Details: Substance Code

    System: http://hl7.org/fhir/ValueSet/substance-code

  • Details: SNOMED CT

    System: http://snomed.info/sct

• AllergyIntolerance.reaction.manifestation

  Description: The clinical symptoms, signs, or both that are observed or associated with the adverse reaction event.

  Details: SNOMED CT Clinical Findings

  System: http://snomed.info/sct

• AllergyIntolerance.reaction.severity

  Description: The clinical assessment of the severity of a reaction event as a whole.

  Details: AllergyIntoleranceSeverity

  System: http://hl7.org/fhir/reaction-event-severity

Extensions

All URLs for custom extensions are defined as https://fhir-ehr.cerner.com/r4/StructureDefinition/{id}

Table - Extensions

ID	Value[x] Type	Description
precision	CodeableConcept	The indication of the precision of a given value.