---
type: "resource"
title: "AllergyIntolerance"
resource: "AllergyIntolerance"
---
# AllergyIntolerance


## Introduction


## Scope and Usage

A record of a clinical assessment of an allergy or intolerance; a propensity, or a potential risk to an individual, to have an adverse reaction on future exposure to the specified substance, or class of substance.

Where a propensity is identified, to record information or evidence about a reaction event that is characterized by any harmful or undesirable physiological response that is specific to the individual and triggered by exposure of an individual to the identified substance or class of substance.

Substances include, but are not limited to: a therapeutic substance administered correctly at an appropriate dosage for the individual; food; material derived from plants or animals; or venom from insect stings.

**Note for Reviewers**

Presently open issues for this resource:

-   This resource represents a condition of susceptibility to a substance, with a list of supporting events and/or symptoms, and has no direct relationship to an event reporting framework; this will be re-assessed when adverse event reporting resource(s) and/or profiles are added to FHIR
-   Other HL7 models and the openEHR archetype have "exposure date" but this is not found in any surveyed systems, so this is left as an extension (more appropriate for adverse event reporting)

## Boundaries and Relationships

This resource is used to provide a single place within the health record to document a range of clinical statements about adverse reactions to substances/products, including:

-   record a clinical assessment of the individual's propensity to a potential future reaction upon re-exposure
-   record cumulative information about the reaction to each exposure, including 'no reaction' if appropriate

Use to record information about the positive presence of the risk of an adverse reaction:

-   to support direct clinical care of an individual
-   as part of a managed adverse reaction or allergy/intolerance list
-   to support exchange of information about the propensity and events related to adverse reactions
-   to inform adverse reaction reporting
-   to assist computerized knowledge-based activities such as clinical decision support and alerts

Use to record information about adverse reactions to a broad range of substances, including: biological & blood products; incipients and excipients in medicinal preparations; foods; metal salts; and organic chemical compounds.

Adverse reactions may be:

-   an allergy (typically type I hypersensitivity, plus other "allergy-like" reactions, including pseudoallergy)
-   an intolerance (typically non-immune adverse reactions that are not determined or perceived to be allergic or "allergy-like", and are to some degree idiosyncratic and/or individually specific \[i.e. are not a reaction that is expected to occur with most or all patients given similar circumstances\])

In clinical practice distinguishing between allergy and intolerance is difficult and might not be practical. Often the term "allergy" is used rather generically and may overlap with "intolerance", and the boundaries between these concepts might not be well-defined or understood. As noted above, the term "intolerance" should generally be applied to a propensity for adverse reactions which is either determined (to the extent that is possible) or perceived to not be allergic or "allergy-like". If it is not possible to determine whether a particular propensity condition is an allergy or an intolerance, then the type element should be omitted from the resource. Identification of the type of reaction is not a proxy for seriousness or risk of harm to the patient, which is better expressed in the documentation of the clinical manifestation and the assessment of criticality.

The sensitivity in the case of either an allergy or intolerance is unique to the individual, and is distinguished from those reactions that are a property of the circumstance, such as toxicity of a food or drug, overdose, drug-drug, drug-food, or drug-disease interaction (which are reactions that would be expected to occur for any individual given the same circumstances).

The risk of an adverse reaction event or manifestation should not be recorded without identifying a proposed causative substance (including pharmaceutical products) or class of substance. If there is uncertainty that a specific substance is the cause, this uncertainty can be recorded using the 'verificationStatus' data element. If there are multiple possible substances that may have caused a reaction/manifestation, each substance should be recorded using a separate instance of this resource with the 'verificationStatus' set to an initial state of 'unconfirmed' so that adverse reaction checking can be supported in clinical systems. If a substance, agent or class is later proven not to be the cause for a given reaction then the 'verificationStatus' can be modified to 'refuted'.

This resource has been designed to allow recording of information about a specific substance (e.g., amoxicillin, oysters, or bee sting venom) or pharmaceutical product or, alternatively, a class of substance (e.g., penicillins). If a class of substance is recorded, then identification of the exact substance can be recorded on a per exposure basis.

The scope of this FHIR resource has deliberately focused on identifying a pragmatic data set that is used in most clinical systems or will be suitable for most common clinical scenarios; [extensions can be used](extensibility) to add additional detail if required. Examples of clinical situations where the extension may be required include: a detailed allergist/immunologist assessment, for reporting to regulatory bodies or use in a clinical trial.

The act of recording any adverse reaction in a health record involves the clinical assessment that a potential hazard exists for an individual if they are exposed to the same substance/product/class in the future - that is, a relative contraindication - and, in the absence of additional information indicating a higher level of potential risk, the default 'criticality' value should be set to 'Low Risk'. If a clinician considers that it is not safe for the individual to be deliberately re-exposed to the substance/product again, for example, following a manifestation of a life-threatening anaphylaxis, then the 'criticality' data element should be amended to 'High Risk'.

A formal adverse event report to regulatory bodies is a document that will contain a broad range of information in addition to the specific details about the adverse reaction. The report could utilize parts of this resource plus include additional data as required per jurisdiction.

An adverse reaction or allergy/intolerance list is a record of all identified propensities for an adverse reaction for the individual upon future exposure to the substance/product or class, plus provides potential access to the evidence provided by details about each reaction event, such as manifestation.

Valuable first-level information that could be presented to the clinician when they need to assess propensity for future reactions are:

-   statements about previous clinical manifestations following exposure
-   source of the information/reporter
-   the 'criticality' flag

Second-level information can be drawn from each exposure event and links to additional detailed information such as history, examination and diagnoses stored elsewhere in the record, if it is available.

**AllergyIntolerance and RiskAssessment**

AllergyIntolerance describes a specific type of risk - propensity to reaction to a substance/product while [RiskAssessment](riskassessment) describes general risks to a subject, not generally based on a reaction.

**AllergyIntolerance and Immunization.reaction**

[Immunization.reaction](immunization-definitions#Immunization.reaction) may be an indication of an allergy or intolerance. If this is deemed to be the case, a separate [AllergyIntolerance](allergyintolerance) record should be created to indicate it, as most systems will not query against past immunization.reactions.

**Misuse**

-   The allergy/intolerance list exists as a patient safety tool to inform decision support around ordering of medications and nutrition and to guide clinical treatment. Other reactions triggered by physical stimuli -- light, heat, cold, pressure, vibration, which may mimic allergic or intolerance reactions, should be recorded as [Condition](condition) on the problem list, not using AllergyIntolerance.
-   Not to be used to record adverse events, including failures of clinical process, interventions or products. For example, abnormal use or mistakes/errors made in maladministration of an agent or substance, incorrect dosage, mislabeling, harm or injury caused by an intervention or procedure, overdose/poisoning, etc.
-   Not to be used as a proxy for an adverse event report. See above for how it may be used as one component of an adverse event report.
-   Not to be used for recording alerts. Alerts are handled using [Flag](flag) or - where event-specific, [DetectedIssue](detectedissue).
-   Not to be used for recording failed therapy.

## Notes


### Negated Allergies and Intolerances

It is important to differentiate between affirmatively stating that a patient has no known allergies versus either not including allergies in the record (for example an episodic document where the allergies are not considered relevant to the document); or asserting that allergies were not reviewed and are unknown.

Allergies with the verificationStatus "entered-in-error" indicate that the allergy or intolerance statement is entered by mistake and hence invalid.

Allergies with the verificationStatus "refuted" must be displayed to indicate that a reaction to a substance has been ruled out with a high level of clinical certainty (e.g. additional testing, re-challenging). When the allergy or intolerance is refuted, other elements may be retained for legal reasons, but those other elements are no longer clinically relevant.

Prior to adding a new allergy/intolerance, a list of existing negated and refuted reactions should be reviewed and reconciled.

**Allergies Not Reviewed, Not Asked**

When a sending system does not have any information about allergies being reviewed or the statement is about allergies not being asked yet, then the [List](list) resource should be used to indicate the List.emptyReason.code="notasked".

**Allergies Reviewed, None Identified**

Systems may use the List.emptyReason when a statement is about the full scope of the list (i.e. the patient has no known allergies or intolerances of any type). However, it is generally preferred to use an AllergyIntolerance.code such as "No known allergies" (e.g., SNOMED CT: 716186003 |No known allergy (situation)|), so that all allergy data will be available and queryable from AllergyIntolerance resource instances. Negated AllergyIntolerance instances are also typically used when the record is more fine-grained (e.g. no drug allergies, no food allergies, no nut allergies, etc.).

However, it is possible to include negation statements that apply at the level of the whole list and it is also possible to have separate lists for things like medication allergies vs. food allergies, where that is appropriate to the architecture. Also note that care should be used when adding new AllergyIntolerances to a list to ensure that any negation statements that are voided by the addition of a new record are removed from the list. E.g. If the list contains a "no known food allergies" record and you add an "intolerance to grape flavor" record, then be sure you remove the "no known food allergies" record.

The substanceExposureRisk extension is also available for use as a more completely structured and flexible alternative to the 'code' element for representing positive and negative allergy and intolerance statements (either the 'code' element or the substanceExposureRisk extension may be used, but not both).

No Known Allergies

<?xml version="1.0" encoding="UTF-8"?>
<AllergyIntolerance xmlns="http://hl7.org/fhir">
  <id value="nka"/> 
  <text> 
	<status value="generated"/> 
	<div xmlns="http://www.w3.org/1999/xhtml">
	  <p> No Known Allergy</p> 
	  <p> recordedDate:2015-08-06</p> 
	</div>    
  </text> 
		 
  <code> 
	<coding> 
	  <system value="http://snomed.info/sct"/> 
	  <code value="716186003"/> 
	  <display value="No Known Allergy (situation)"/> 
	</coding> 
	<text value="NKA"/> 
  </code> 

  <patient> 
	<reference value="Patient/mom"/> 
  </patient> 

  <!--   the date that this entry was recorded   -->  
  <recordedDate value="2015-08-06T15:37:31-06:00"/> 
	  
  <!--   who made the record / last updated it   -->
  <recorder> 
	<reference value="Practitioner/example"/> 
  </recorder>   
</AllergyIntolerance>

No Known Allergies, using [List](list).emptyReason (discouraged)

  <List xmlns="http://hl7.org/fhir" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://hl7.org/fhir ..\\..\\schema\\list.xsd">
 <id value="example-empty-allergy"/>
  <text>
    <status value="generated"/>
    <div xmlns="http://www.w3.org/1999/xhtml">
      <p> The patient is not aware of any allergies.</p>
    </div>
  </text>
<code>
    <coding>
      <system value="http://loinc.org"/>
      <code value="52472-8"/>
      <display value="Allergies and Adverse Drug Reactions"/>
    </coding>
    <text value="Current Allergy List"/>
  </code>
  <source>
    <reference value="Patient/example"/>
  </source>
  <status value="current"/>
  <date value="2012-11-26T07:30:23+11:00"/>
  <mode value="snapshot"/>
  <emptyReason>
    <coding>
      <system value="http://hl7.org/fhir/special-values"/>
      <code value="nil-known"/>
      <display value="Nil Known"/>
    </coding>
    <text value="The patient is not aware of any allergies."/>
  </emptyReason>
</List>

No Known Food Allergies and Medication Allergy List

  <?xml version="1.0" encoding="UTF-8"?>
<List xmlns="http://hl7.org/fhir" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://hl7.org/fhir ..\\..\\schema\\list.xsd">
  <id value="current-allergies"/>
  <text>
    <status value="generated"/>
    <div xmlns="http://www.w3.org/1999/xhtml">
      <p>Patient Peter Chalmers, DOB = Dec 25, 1974, MRN = 12345 (Acme Healthcare) has the following allergies</p>
      <ul>
        <li>No known food allergies</li>
        <li>Allergenic extract, penicillin (high)</li>
      </ul>
    </div>
  </text>
  <code>
    <coding>
      <system value="http://loinc.org"/>
      <code value="52472-8"/>
      <display value="Allergies and Adverse Drug Reactions"/>
    </coding>
    <text value="Current Allergy List"/>
  </code>
  <source>
    <reference value="Patient/example"/>
  </source>
  <status value="current"/>
  <date value="2015-07-14T23:10:23+11:00"/>
  <mode value="snapshot"/>
  <entry>
    <item> 
      <reference value="AllergyIntolerance/nofoodallergies"/>
    </item>
  </entry>
  <entry>
    <item> 
      <reference value="AllergyIntolerance/penicillin"/>
    </item>
  </entry>  
</List>

## StructureDefinition

### Elements (Simplified)

- **[AllergyIntolerance](/allergyintolerance-definitions#AllergyIntolerance)** [0..*]: - Allergy or Intolerance (generally: Risk of adverse reaction to a substance)
- **[AllergyIntolerance.identifier](/allergyintolerance-definitions#AllergyIntolerance.identifier)** [0..*]: [Identifier](/Identifier) External ids for this item
- **[AllergyIntolerance.clinicalStatus](/allergyintolerance-definitions#AllergyIntolerance.clinicalStatus)** [0..1]: [CodeableConcept](/CodeableConcept) required:[allergyintolerance-clinical](/valueset-allergyintolerance-clinical) active | inactive | resolved
- **[AllergyIntolerance.verificationStatus](/allergyintolerance-definitions#AllergyIntolerance.verificationStatus)** [0..1]: [CodeableConcept](/CodeableConcept) required:[allergyintolerance-verification](/valueset-allergyintolerance-verification) unconfirmed | presumed | confirmed | refuted | entered-in-error
- **[AllergyIntolerance.type](/allergyintolerance-definitions#AllergyIntolerance.type)** [0..1]: [CodeableConcept](/CodeableConcept) preferred:[allergy-intolerance-type](/valueset-allergy-intolerance-type) allergy | intolerance - Underlying mechanism (if known)
- **[AllergyIntolerance.category](/allergyintolerance-definitions#AllergyIntolerance.category)** [0..*]: [code](/code) required:[allergy-intolerance-category](/valueset-allergy-intolerance-category) food | medication | environment | biologic
- **[AllergyIntolerance.criticality](/allergyintolerance-definitions#AllergyIntolerance.criticality)** [0..1]: [code](/code) required:[allergy-intolerance-criticality](/valueset-allergy-intolerance-criticality) low | high | unable-to-assess
- **[AllergyIntolerance.code](/allergyintolerance-definitions#AllergyIntolerance.code)** [0..1]: [CodeableConcept](/CodeableConcept) example:[allergyintolerance-code](/valueset-allergyintolerance-code) Code that identifies the allergy or intolerance
- **[AllergyIntolerance.patient](/allergyintolerance-definitions#AllergyIntolerance.patient)** [1..1]: Reference([Patient](/Patient)) Who the allergy or intolerance is for
- **[AllergyIntolerance.encounter](/allergyintolerance-definitions#AllergyIntolerance.encounter)** [0..1]: Reference([Encounter](/Encounter)) Encounter when the allergy or intolerance was asserted
- **[AllergyIntolerance.onset[x]](/allergyintolerance-definitions#AllergyIntolerance.onset%5Bx%5D)** [0..1]: [dateTime](/dateTime), [Age](/Age), [Period](/Period), [Range](/Range), [string](/string) When allergy or intolerance was identified
- **[AllergyIntolerance.recordedDate](/allergyintolerance-definitions#AllergyIntolerance.recordedDate)** [0..1]: [dateTime](/dateTime) Date allergy or intolerance was first recorded
- **[AllergyIntolerance.recorder](/allergyintolerance-definitions#AllergyIntolerance.recorder)** [0..1]: [Reference(Practitioner](/Reference(Practitioner), [PractitionerRole](/PractitionerRole), [Patient](/Patient), [RelatedPerson](/RelatedPerson), [Organization)](/Organization)) Who recorded the sensitivity
- **[AllergyIntolerance.asserter](/allergyintolerance-definitions#AllergyIntolerance.asserter)** [0..1]: [Reference(Patient](/Reference(Patient), [RelatedPerson](/RelatedPerson), [Practitioner](/Practitioner), [PractitionerRole)](/PractitionerRole)) Source of the information about the allergy
- **[AllergyIntolerance.lastReactionOccurrence](/allergyintolerance-definitions#AllergyIntolerance.lastReactionOccurrence)** [0..1]: [dateTime](/dateTime) Date(/time) of last known occurrence of a reaction
- **[AllergyIntolerance.note](/allergyintolerance-definitions#AllergyIntolerance.note)** [0..*]: [Annotation](/Annotation) Additional text not captured in other fields
- **[AllergyIntolerance.reaction](/allergyintolerance-definitions#AllergyIntolerance.reaction)** [0..*]: [BackboneElement](/BackboneElement) Adverse Reaction Events linked to exposure to substance
- **[AllergyIntolerance.reaction.substance](/allergyintolerance-definitions#AllergyIntolerance.reaction.substance)** [0..1]: [CodeableConcept](/CodeableConcept) example:[substance-code](/valueset-substance-code) Specific substance or pharmaceutical product considered to be responsible for event
- **[AllergyIntolerance.reaction.manifestation](/allergyintolerance-definitions#AllergyIntolerance.reaction.manifestation)** [1..*]: [CodeableReference](/CodeableReference) example:[clinical-findings](/valueset-clinical-findings) Clinical symptoms/signs associated with the Event
- **[AllergyIntolerance.reaction.description](/allergyintolerance-definitions#AllergyIntolerance.reaction.description)** [0..1]: [string](/string) Description of the event as a whole
- **[AllergyIntolerance.reaction.onset](/allergyintolerance-definitions#AllergyIntolerance.reaction.onset)** [0..1]: [dateTime](/dateTime) Date(/time) when manifestations showed
- **[AllergyIntolerance.reaction.severity](/allergyintolerance-definitions#AllergyIntolerance.reaction.severity)** [0..1]: [code](/code) required:[reaction-event-severity](/valueset-reaction-event-severity) mild | moderate | severe (of event as a whole)
- **[AllergyIntolerance.reaction.exposureRoute](/allergyintolerance-definitions#AllergyIntolerance.reaction.exposureRoute)** [0..1]: [CodeableConcept](/CodeableConcept) example:[route-codes](/valueset-route-codes) How the subject was exposed to the substance
- **[AllergyIntolerance.reaction.note](/allergyintolerance-definitions#AllergyIntolerance.reaction.note)** [0..*]: [Annotation](/Annotation) Text about event not captured in other fields

## Mappings

- [AllergyIntolerance Mappings](/allergyintolerance-mappings) — 48 mapping entries

## Implementation Guide


### implementationguide-AllergyIntolerance-core.xml



```xml
<?xml version="1.0" encoding="UTF-8"?>

<ImplementationGuide xmlns="http://hl7.org/fhir">
  <id value="AllergyIntolerance-core"/>
  <version value="0.1"/>
  <name value="AllergyIntoleranceHL7Extensions"/>
  <title value="Allergy Intolerance  H L7  Extensions"/>
  <status value="draft"/>
  <date value="2015-02-21T00:00:00.000"/>
  <publisher value="Health Level Seven, Inc. - FHIR WG"/>
  <description value="Defines common extensions used with or related to the AllergyIntolerance resource"/>
</ImplementationGuide>
```


## Resource Packs


### list-AllergyIntolerance-packs.xml



```xml
<?xml version="1.0" encoding="UTF-8"?>

<List xmlns="http://hl7.org/fhir">
  <id value="AllergyIntolerance-packs"/>
  <status value="current"/>
  <mode value="working"/>
  <entry>
    <item>
      <reference value="ImplementationGuide/AllergyIntolerance-openehr"/>
    </item>
  </entry>
  <entry>
    <item>
      <reference value="ImplementationGuide/AllergyIntolerance-core"/>
    </item>
  </entry>
</List>
```


## Search Parameters

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

[Full Search Parameters](/allergyintolerance-search)

## Examples

- [allergyintolerance-example](/allergyintolerance-example-allergyintolerance-example) — allergyintolerance-example
- [allergyintolerance-examples-header](/allergyintolerance-example-allergyintolerance-examples-header) — allergyintolerance-examples-header
- [example](/allergyintolerance-example-example) — allergyintolerance-example — A typical Food Allergy
- [fishallergy](/allergyintolerance-example-fishallergy) — allergyintolerance-fishallergy — An allergy to a substance with additional details in notes
- [medication](/allergyintolerance-example-medication) — allergyintolerance-medication — A typical Medication allergy from a clinical system
- [nka](/allergyintolerance-example-nka) — allergyintolerance-nka — No Known Allergy
- [nkda](/allergyintolerance-example-nkda) — allergyintolerance-nkda — No Known Drug Allergy
- [nkla](/allergyintolerance-example-nkla) — allergyintolerance-nkla — No Known Latext Allergy

[Full Examples](/allergyintolerance-examples)

## Mapping Exceptions


### allergyintolerance-fivews-mapping-exceptions.xml

### Unmapped Elements
- **FiveWs.actor** — Unknown
- **FiveWs.cause** — Unknown
- **FiveWs.version** — Unknown
- **FiveWs.witness** — Unknown
- **FiveWs.where** — Unknown
- **FiveWs.why** — Unknown
- **FiveWs.who** — Unknown
- **FiveWs.planned** — Unknown
- **FiveWs.done** — Unknown