The FHIR R4 AllergyIntolerance resource captures information about a patient’s allergies or intolerances to substances such as medications, foods, or environmental agents. This information helps support safe clinical decision-making by documenting known adverse sensitivities and reactions.
Health Gorilla exposes AllergyIntolerance as part of its FHIR R4 API to support patient-centric clinical data access.
Use Cases
- Retrieving a patient’s known allergies prior to prescribing medications
- Recording newly identified allergies during patient intake or clinical encounters
- Reviewing allergy history as part of longitudinal patient records
Scope and Behavior
This documentation describes the FHIR R4 API interface for AllergyIntolerance. Health Gorilla’s platform may use additional internal services and data standards to acquire, normalize, and route clinical information. Only the FHIR R4–exposed behavior is documented here.
Health Gorilla supports a subset of the HL7 FHIR R4 AllergyIntolerance resource. Not all optional elements defined in the HL7 specification may be stored, indexed, or returned. Unsupported or unrecognized elements may be ignored or normalized during processing.
In Health Gorilla, AllergyIntolerance is most commonly accessed as part of patient record retrieval workflows, where allergy data is aggregated from connected clinical sources and normalized for longitudinal review. This resource supports medication safety, care coordination, and clinical review use cases by exposing known allergy and intolerance information alongside other patient clinical data.
Authentication
All requests to the FHIR R4 API require OAuth 2.0 authentication using a bearer token. Unauthorized requests return a 401 Unauthorized response.
Required Scopes
allergyintolerance.readfor GETallergyintolerance.writefor POST, PUT, and DELETE
For details on authentication and token acquisition, see OAuth 2.0 Authentication.
Search Behavior
- Searches are scoped to the authenticated tenant.
- The
patientparameter is required for patient-scoped searches and is recommended for most search use cases. - Results are returned as a FHIR
Bundle. - Pagination may be applied. Use standard FHIR pagination links (
Bundle.link) to retrieve additional result pages.
Note: Supported parameters and behavior may vary by configuration.
Search Parameters
Searches are scoped to a single patient. Provide patient, or search on _lastUpdated alone to retrieve records by when they were written.
| Parameter | Required | Description |
|---|---|---|
patient | Yes | The patient whose records you want, as Patient/{id}. You can also search by a patient identifier using patient.identifier. |
_lastUpdated | No | Filters on when the record was last written in the Health Gorilla FHIR server. Accepts a comparison prefix, for example ge2025-01-01. |
_offset | No | Skips the given number of results. A Health Gorilla pagination parameter, separate from _count with the next link. |
_count | No | Limits the number of results returned per page. |
_tag | No | Filters on meta.tag. |
_security | No | Filters on meta.security. |
The search also accepts _revinclude=Provenance:target, which returns the Provenance records describing where the results came from.
Resource Attributes
| Attribute | Description | Example Values | FHIR Data Type |
|---|---|---|---|
patient | Patient who has the allergy or intolerance | Patient/{id} | Reference(Patient) |
code | Allergen or substance | SNOMED CT or RxNorm codes | CodeableConcept |
type | Type of sensitivity | allergy, intolerance | code |
category | Allergen category | food, medication | code[] |
criticality | Potential severity if exposed | high | code |
clinicalStatus | Current status | active | CodeableConcept |
verificationStatus | Certainty of allergy | confirmed | CodeableConcept |
onset | When the allergy began | YYYY-MM-DD | dateTime, Age, Period |
recordedDate | When recorded | YYYY-MM-DD | dateTime |
lastOccurrence | Most recent reaction | YYYY-MM-DD | dateTime |
recorder | Who recorded the allergy | Practitioner/{id} | Reference |
reaction.manifestation | Reaction symptoms | hives, dyspnea | CodeableConcept[] |
reaction.severity | Reaction severity | mild, moderate, severe | code |
reaction.substance | Specific reaction substance | penicillin G | CodeableConcept |
reaction.description | Text description | Free text | string |
Notifications
The FHIR R4 API does not provide direct resource-change subscriptions for AllergyIntolerance. Changes to allergy information may surface through broader notification workflows, depending on enabled Health Gorilla products and configuration.
Error Handling
All AllergyIntolerance operations use standard Health Gorilla error handling and return a FHIR OperationOutcome resource for structured error details. For more information, go to Error Handling.