{
  "resourceType": "AllergyIntolerance",
  "id": "PatientAllergy Instance Example",
  "meta": {
    "profile": [
      "http://hl7.org/fhir/us/bser/StructureDefinition/PatientAllergy"
    ]
  },
  "verificationStatus": "confirmed",
  "type": "allergy",
  "patient": {
    "reference": "PatientRole/InstanceExample"
  },
  "onsetAge": {
    "value": 20,
    "unit": "yrs",
    "system": "http://unitsofmeasure.org",
    "code": "yrs"
  },
  "reaction": [
    {
      "substance": {
        "coding": [
          {
            "system": "http://snomed.info/sct",
            "code": "3718001",
            "display": "Cow's milk"
          }
        ]
      },
      "manifestation": [
        {
          "coding": [
            {
              "system": "http://snomed.info/sct",
              "code": "422400008",
              "display": "Vomiting"
            }
          ]
        }
      ],
      "severity": "mild"
    }
  ]
}