AllergyIntolerance

Maturity Level	Security Category	Resource Category
3	Patient	Clinical

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

Resource Content

Name	Required	Type	Description & Constraints
identifier		Identifier[]	External ids for this item
clinicalStatus		CodeableConcept	active \| inactive \| resolved
verificationStatus		CodeableConcept	unconfirmed \| confirmed \| refuted \| entered-in-error
type		code	allergy \| intolerance - Underlying mechanism (if known)
category		code[]	food \| medication \| environment \| biologic
criticality		code	low \| high \| unable-to-assess
code		CodeableConcept	Code that identifies the allergy or intolerance
patient	✓	Reference<Patient>	Who the sensitivity is for
encounter		Reference<Encounter>	Encounter when the allergy or intolerance was asserted
onset[x]		dateTime \| Age \| Period \| Range \| string	When allergy or intolerance was identified
recordedDate		dateTime	Date first version of the resource instance was recorded
recorder		Reference<Practitioner\| PractitionerRole\| Patient\| RelatedPerson>	Who recorded the sensitivity
asserter		Reference<Patient\| RelatedPerson\| Practitioner\| PractitionerRole>	Source of the information about the allergy
lastOccurrence		dateTime	Date(/time) of last known occurrence of a reaction
note		Annotation[]	Additional text not captured in other fields
reaction		BackboneElement[]	Adverse Reaction Events linked to exposure to substance
└─ substance		CodeableConcept	Specific substance or pharmaceutical product considered to be responsible for event
└─ manifestation	✓	CodeableConcept[]	Clinical symptoms/signs associated with the Event
└─ description		string	Description of the event as a whole
└─ onset		dateTime	Date(/time) when manifestations showed
└─ severity		code	mild \| moderate \| severe (of event as a whole)
└─ exposureRoute		CodeableConcept	How the subject was exposed to the substance
└─ note		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 \| AllergyIntolerance.reaction.substance`
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`

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.

Boundaries and Relationships

Purpose

This resource provides a single place within the health record to document clinical statements about adverse reactions to substances/products, including:

Recording clinical assessment of potential future reactions upon re-exposure
Recording cumulative information about reactions to each exposure, including 'no reaction'

Use Cases

Record information about adverse reaction risks for:

Direct clinical care of an individual
Managed adverse reaction or allergy/intolerance lists
Information exchange about adverse reaction events
Adverse reaction reporting
Clinical decision support and alerts

Scope

Can record reactions to:

Biological & blood products
Medicinal preparations (incipients and excipients)
Foods
Metal salts
Organic chemical compounds

Types of Adverse Reactions

Allergy

Typically type I hypersensitivity
Includes other "allergy-like" reactions and pseudoallergy

Intolerance

Non-immune adverse reactions
Not determined/perceived to be allergic
Idiosyncratic and individually specific
Not expected to occur in most patients under similar circumstances

Note: In clinical practice, distinguishing between allergy and intolerance can be difficult. If uncertainty exists, the type element should be omitted.

Important Considerations

Individual Sensitivity

Reactions must be unique to the individual
Distinguished from circumstantial reactions like:
- Food/drug toxicity
- Overdose
- Drug-drug interactions
- Drug-food interactions
- Drug-disease interactions

Recording Guidelines

Causative Substance:
- Must identify a proposed causative substance or class
- Use verificationStatus to indicate uncertainty
- Create separate instances for multiple possible causes
Substance Documentation:
- Can record specific substances (e.g., amoxicillin, oysters, bee sting venom)
- Can record class of substances (e.g., penicillins)
- Exact substance can be recorded per exposure
Risk Assessment:
- Default criticality should be 'Low Risk'
- Set to 'High Risk' if re-exposure is unsafe (e.g., after life-threatening anaphylaxis)

Clinical Information Hierarchy

First-Level Information

Previous clinical manifestations
Information source/reporter
Criticality flag

Second-Level Information

Exposure event details
Links to additional clinical information:
- History
- Examination
- Diagnoses

AllergyIntolerance vs RiskAssessment

AllergyIntolerance: Specific substance reaction risks
RiskAssessment: General patient risks not based on reactions

AllergyIntolerance vs Immunization.reaction

Create separate AllergyIntolerance record if immunization reaction indicates allergy
Most systems don't query immunization.reactions

Misuse Prevention

Do NOT use this resource for:

Physical stimuli reactions (use Condition instead):
- Light
- Heat
- Cold
- Pressure
- Vibration
Adverse events from:
- Clinical process failures
- Intervention errors
- Product malfunctions
- Incorrect dosage
- Mislabeling
- Procedure injuries
- Overdose/poisoning
Standalone adverse event reports
Alerts (use Flag or DetectedIssue)
Failed therapy documentation

Referenced Elements

This resource is referenced by: