Langcare Langcare MCP Fhir Allergy Adverse Reaction Summary

Allergy & Adverse Reaction Summary

Overview

Pull all AllergyIntolerance resources for a patient. Categorize by type (drug, food, environmental). Grade severity and criticality. Flag high-risk allergies that require special clinical attention (anaphylaxis history, contrast dye, latex, NSAID sensitivity). Cross-reference against current medications to detect active conflicts. Output a structured summary with actionable safety flags.

FHIR Resources Used

Instructions

Step 1: Pull All AllergyIntolerance Resources

Tool: fhir_search
resourceType: "AllergyIntolerance"
queryParams: "patient=[patient-id]"

Retrieve all records regardless of clinical status to capture full history. For each entry extract:

• code.coding: Substance (RxNorm for drugs, SNOMED CT for non-drugs)
• clinicalStatus: active, inactive, resolved
• verificationStatus: confirmed, unconfirmed, refuted, entered-in-error
• type: allergy vs intolerance
• category: food, medication, environment, biologic
• criticality: low, high, unable-to-assess
• reaction[]: Each reaction event
  • manifestation[].coding[].display: What happened (hives, anaphylaxis, rash, etc.)
  • severity: mild, moderate, severe
  • onset: When the reaction occurred
  • substance: Specific substance if different from the top-level code
• onsetDateTime: When allergy was first identified
• recorder: Who documented it
• note: Free-text notes

Step 2: Categorize Allergies

Group into four categories:

Drug Allergies (category = "medication"):

• Identify drug class from the substance code or name
• Check for class-level allergies vs specific drug allergies
• Note if the allergy is to a drug class (e.g., "penicillins") vs specific drug (e.g., "amoxicillin")

Food Allergies (category = "food"):

• Common: peanuts, tree nuts, shellfish, milk, eggs, wheat, soy, fish
• Note severity -- food allergies with anaphylaxis history are high-risk

Environmental Allergies (category = "environment"):

• Pollen, dust mites, mold, animal dander, insect venom
• Usually lower clinical urgency unless anaphylaxis to insect stings

Biologic/Other (category = "biologic" or uncategorized):

• Latex, contrast dye, blood products, vaccines

Step 3: Flag High-Risk Allergies

Scan the allergy list for the following high-risk patterns:

Anaphylaxis History:

• Any allergy where reaction[].manifestation includes SNOMED 39579001 (Anaphylaxis) or display text contains "anaphylaxis" or "anaphylactic"
• Flag with: "ANAPHYLAXIS RISK -- Ensure epinephrine availability"

Contrast Dye Allergy:

• Substance code or display contains "iodine", "contrast", "iodinated contrast"
• Flag with: "CONTRAST ALLERGY -- Premedication protocol required for CT with contrast"

Latex Allergy:

• Substance = SNOMED 111088007 (Latex) or display contains "latex"
• Flag with: "LATEX ALLERGY -- Use non-latex gloves and equipment"
• Check for cross-reactive foods: banana, avocado, kiwi, chestnut

NSAID Sensitivity:

• Allergy to aspirin, ibuprofen, naproxen, or "NSAIDs" as a class
• Flag with: "NSAID SENSITIVITY -- Avoid all COX inhibitors. Consider acetaminophen as alternative."
• Check for aspirin-exacerbated respiratory disease (Samter's triad): NSAID allergy + asthma + nasal polyps

Sulfonamide Allergy:

• Allergy to "sulfa", "sulfamethoxazole", "trimethoprim-sulfamethoxazole", or sulfonamide antibiotics
• Note: Sulfonamide antibiotic allergy does NOT contraindicate non-antibiotic sulfonamides (furosemide, thiazides, celecoxib) -- cross-reactivity is negligible but document awareness

Opioid Allergy:

• If allergy to one opioid, check if it is a true allergy (e.g., anaphylaxis) or a side effect misclassified as allergy (nausea, itching are common opioid side effects, not allergies)
• Flag specific opioid vs opioid class

Step 4: Check Cross-Reactivity Patterns

Apply known cross-reactivity rules:

Penicillin Cross-Reactivity:

• Penicillin allergy -> ~2% cross-reactivity with cephalosporins (1st gen > 2nd gen > 3rd gen)
• Penicillin allergy -> ~1% cross-reactivity with carbapenems
• If penicillin allergy with anaphylaxis: avoid all beta-lactams pending allergy testing
• If penicillin allergy with mild rash only: cephalosporins (2nd gen+) generally safe

Cephalosporin Cross-Reactivity:

• 1st gen cephalosporins (cephalexin, cefazolin) have highest cross-reactivity with penicillin
• Cross-reactivity is side-chain dependent, not ring-structure dependent (current evidence)

ACE Inhibitor Angioedema:

• ACE inhibitor-induced angioedema -> contraindication to all ACE inhibitors
• ARBs are generally safe alternatives (low cross-reactivity)
• Document as a separate allergy entry if not already present

Statin Myopathy:

• Myopathy/rhabdomyolysis with one statin does not necessarily contraindicate all statins
• Hydrophilic statins (rosuvastatin, pravastatin) may be tolerated

Step 5: Cross-Reference with Active Medications

Tool: fhir_search
resourceType: "MedicationRequest"
queryParams: "patient=[patient-id]&status=active"

For each active medication, check against the allergy list:

• Direct match: medication name/code matches allergy substance
• Class match: medication belongs to same drug class as allergy substance
• Cross-reactivity match: medication has known cross-reactivity with allergy substance

Flag any active conflict as:

ACTIVE CONFLICT: Patient is on [medication] but has documented allergy to [substance]
Reaction history: [manifestation] - Severity: [severity]
Action required: Verify with prescriber. This may be a monitored override or a documentation error.

Step 6: Assess Documentation Quality

Flag documentation issues:

• Allergy with no reaction documented (reaction array empty)
• Allergy with no severity specified
• verificationStatus = "unconfirmed" for allergies older than 1 year (should be confirmed or refuted)
• type not specified (allergy vs intolerance distinction missing)
• No allergies documented AND no "No Known Allergies" entry (allergy status unknown vs NKDA)

Step 7: Format Output

ALLERGY & ADVERSE REACTION SUMMARY
====================================
Patient: [name] ([patient-id])
Reviewed: [timestamp]
Total Entries: [count]
Allergy Status: [Reviewed / Not Reviewed / NKDA]

HIGH-RISK ALERTS
================
[!] ANAPHYLAXIS RISK: [substance] - ensure epinephrine access
[!] CONTRAST ALLERGY: Premedication required
[!] LATEX ALLERGY: Non-latex equipment required
[!] ACTIVE CONFLICT: On [medication] with allergy to [substance]

DRUG ALLERGIES
==============
1. [Substance] (RxNorm: [code])
   Type: Allergy | Status: Active | Criticality: High
   Reaction: [manifestation] | Severity: Severe
   Cross-reactivity note: [if applicable]
   Documented: [date] by [recorder]
2. ...

FOOD ALLERGIES
==============
1. [Substance] - Reaction: [manifestation] - Severity: [severity]
2. ...

ENVIRONMENTAL ALLERGIES
=======================
1. [Substance] - Reaction: [manifestation] - Severity: [severity]
2. ...

INTOLERANCES (Non-Allergic)
============================
1. [Substance] - Type: Intolerance - Reaction: [manifestation]
2. ...

DOCUMENTATION QUALITY
=====================
- [N] allergies missing reaction details
- [N] allergies with unconfirmed verification status
- [Notes on documentation gaps]

CROSS-REACTIVITY NOTES
=======================
- [Relevant cross-reactivity information based on documented allergies]

Examples

Example 1: Patient With Multiple Drug Allergies

User says: "Check allergies for patient 33221"

Actions:

1. fhir_search AllergyIntolerance?patient=33221 -- returns 5 entries
2. fhir_search MedicationRequest?patient=33221&status=active -- returns 8 medications

Result:

ALLERGY & ADVERSE REACTION SUMMARY
====================================
Patient: David Park (33221)
Reviewed: 2026-02-07T10:00:00Z
Total Entries: 5
Allergy Status: Reviewed

HIGH-RISK ALERTS
================
[!] ANAPHYLAXIS RISK: Penicillin - ensure epinephrine access
[!] ACTIVE CONFLICT: On cephalexin (Keflex) with documented penicillin allergy
    (anaphylaxis history) - IMMEDIATE REVIEW REQUIRED

DRUG ALLERGIES
==============
1. Penicillin (RxNorm: 7980)
   Type: Allergy | Status: Active | Criticality: High
   Reaction: Anaphylaxis | Severity: Severe
   Cross-reactivity: 2% risk with cephalosporins. Given anaphylaxis history,
   avoid all beta-lactams pending formal allergy testing.
   Documented: 2019-05-12

2. Codeine (RxNorm: 2670)
   Type: Intolerance | Status: Active | Criticality: Low
   Reaction: Nausea, vomiting | Severity: Mild
   Note: Likely opioid side effect, not true allergy. Other opioids
   may be tolerated. Consider reclassifying as intolerance if not already.
   Documented: 2020-08-03

FOOD ALLERGIES
==============
1. Shellfish (SNOMED: 278840001)
   Reaction: Urticaria, throat tightness | Severity: Moderate
   Note: Monitor for iodinated contrast cross-reactivity (historically
   cited but evidence is weak; shellfish allergy is protein-based,
   not iodine-based)

ENVIRONMENTAL ALLERGIES
=======================
1. Dust mites (SNOMED: 260147004)
   Reaction: Rhinitis | Severity: Mild

INTOLERANCES
============
1. Lactose (SNOMED: 782415009)
   Type: Intolerance | Reaction: Bloating, diarrhea | Severity: Mild

DOCUMENTATION QUALITY
=====================
- Codeine entry classified as "allergy" but reaction pattern suggests intolerance
- Dust mite allergy missing severity in FHIR record (inferred as mild from manifestation)

Example 2: No Allergies Documented -- Ambiguous Status

User says: "Does patient 99001 have any allergies?"

Actions:

1. fhir_search AllergyIntolerance?patient=99001 -- returns 0 entries

Result:

ALLERGY & ADVERSE REACTION SUMMARY
====================================
Patient: Lisa Chen (99001)
Reviewed: 2026-02-07T10:15:00Z
Total Entries: 0
Allergy Status: ** NOT REVIEWED **

HIGH-RISK ALERTS
================
[!] ALLERGY STATUS UNKNOWN: No allergy records found. This does NOT mean
    "No Known Allergies" -- it means allergies have never been documented.
    Allergy history MUST be collected before prescribing.

RECOMMENDATION
==============
Ask the patient about:
1. Drug allergies (especially antibiotics, NSAIDs, anesthetics)
2. Food allergies
3. Environmental allergies
4. Latex sensitivity
5. Contrast dye reactions
6. Previous adverse drug reactions

If patient reports no allergies, document a "No Known Allergies" entry:
  Tool: fhir_create
  resourceType: "AllergyIntolerance"
  resource: {
    "clinicalStatus": {"coding": [{"system": "http://terminology.hl7.org/CodeSystem/allergyintolerance-clinical", "code": "active"}]},
    "verificationStatus": {"coding": [{"system": "http://terminology.hl7.org/CodeSystem/allergyintolerance-verification", "code": "confirmed"}]},
    "code": {"coding": [{"system": "http://snomed.info/sct", "code": "716186003", "display": "No known allergy"}]},
    "patient": {"reference": "Patient/99001"}
  }

Troubleshooting

AllergyIntolerance Uses Free Text Instead of Coded Substances

• Some EHR systems populate code.text but not code.coding. Use the display text for matching.
• Attempt fuzzy matching against known drug names and classes for cross-reference purposes.
• Flag these entries for coding improvement: "Allergy to [free text] should be coded with RxNorm/SNOMED for interoperability."

Medication Conflict Detected But May Be Intentional Override

• Clinicians sometimes prescribe medications despite documented allergies after risk-benefit analysis (e.g., penicillin allergy but documented tolerance to amoxicillin after skin testing).
• Check for note or extension fields that indicate a deliberate override.
• Present the conflict but note: "This may be a monitored override. Verify with the prescribing clinician before recommending discontinuation."

AllergyIntolerance Resources Have verificationStatus = "entered-in-error"

• Exclude these from the active summary entirely.
• If the user specifically asks about historical or retracted allergies, include them in a separate "Retracted Entries" section.

Related Skills

• patient-demographics-summary -- for complete patient overview including insurance and contacts
• problem-list-review -- for cross-referencing allergies with conditions
• clinical-summary-generator -- for allergies in the context of a full CCD summary

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