---
type: "codesystem"
title: "Allergy Intolerance Severity"
codesystem: "reaction-event-severity"
---
# Allergy Intolerance Severity

- **Official URL**: http://hl7.org/fhir/reaction-event-severity
- **Version**: 6.0.0
- **Status**: active
- **Name**: AllergyIntoleranceSeverity
- **Title**: Allergy Intolerance Severity
- **Publisher**: HL7 (FHIR Project)
- **Description**: Clinical assessment of the severity of a reaction event as a whole, potentially considering multiple different manifestations.
- **Case Sensitive**: true
- **Content**: complete

## Concepts

| Code | Display | Definition |
| --- | --- | --- |
| mild | Mild | Causes mild physiological effects. |
| moderate | Moderate | Causes moderate physiological effects. |
| severe | Severe | Causes severe physiological effects. |

## CodeSystem XML



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

<CodeSystem xmlns="http://hl7.org/fhir">
  <id value="reaction-event-severity"/>
  <extension url="http://hl7.org/fhir/StructureDefinition/structuredefinition-wg">
    <valueCode value="pc"/>
  </extension>
  <extension url="http://hl7.org/fhir/StructureDefinition/structuredefinition-standards-status">
    <valueCode value="normative"/>
  </extension>
  <extension url="http://hl7.org/fhir/StructureDefinition/structuredefinition-fmm">
    <valueInteger value="3"/>
  </extension>
  <url value="http://hl7.org/fhir/reaction-event-severity"/>
  <identifier>
    <system value="urn:ietf:rfc:3986"/>
    <value value="urn:oid:2.16.840.1.113883.4.642.4.136"/>
  </identifier>
  <identifier>
    <use value="old"/>
    <system value="urn:ietf:rfc:3986"/>
    <value value="urn:oid:2.16.840.1.113883.4.642.1.126"/>
  </identifier>
  <identifier>
    <use value="old"/>
    <system value="urn:ietf:rfc:3986"/>
    <value value="urn:oid:2.16.840.1.113883.4.642.2.56"/>
  </identifier>
  <version value="6.0.0"/>
  <name value="AllergyIntoleranceSeverity"/>
  <title value="Allergy Intolerance Severity"/>
  <status value="active"/>
  <experimental value="false"/>
  <date value="2021-01-05T10:01:24+11:00"/>
  <publisher value="HL7 (FHIR Project)"/>
  <contact>
    <telecom>
      <system value="url"/>
      <value value="http://hl7.org/fhir"/>
    </telecom>
    <telecom>
      <system value="email"/>
      <value value="fhir@lists.hl7.org"/>
    </telecom>
  </contact>
  <description value="Clinical assessment of the severity of a reaction event as a whole, potentially considering multiple different manifestations."/>
  <caseSensitive value="true"/>
  <valueSet value="http://hl7.org/fhir/ValueSet/reaction-event-severity"/>
  <content value="complete"/>
  <concept>
    <code value="mild"/>
    <display value="Mild"/>
    <definition value="Causes mild physiological effects."/>
  </concept>
  <concept>
    <code value="moderate"/>
    <display value="Moderate"/>
    <definition value="Causes moderate physiological effects."/>
  </concept>
  <concept>
    <code value="severe"/>
    <display value="Severe"/>
    <definition value="Causes severe physiological effects."/>
  </concept>
</CodeSystem>
```