PatientReactionType

Reference data entity for types of adverse reactions to allergens. Distinguishes between true allergies (immune-mediated), intolerances (non-immune), and sensitivities.

Overview

PatientReactionType categorizes the mechanism of adverse reactions that patients experience when exposed to allergens. Understanding the reaction type is clinically important because true allergies can be life-threatening and require strict avoidance, while intolerances may allow limited exposure. This distinction affects treatment decisions, medication alternatives, and patient education.

Key Concepts

Reaction Mechanisms

The three main types of adverse reactions:

Type	Mechanism	Severity Potential	Example
Allergy	Immune system (IgE-mediated)	Can be life-threatening	Penicillin anaphylaxis
Intolerance	Non-immune metabolic	Uncomfortable, not dangerous	Lactose intolerance
Sensitivity	Heightened response, non-immune	Variable, usually mild	Caffeine sensitivity

Clinical Distinctions

Allergy (Immune-mediated)

Involves IgE antibodies and immune response
Can cause anaphylaxis (life-threatening)
Reactions occur quickly (minutes to hours)
Even small amounts can trigger reaction
Requires strict avoidance
Examples: Penicillin allergy, peanut allergy, bee sting allergy

Intolerance (Non-immune)

No immune system involvement
Not life-threatening
Reactions may be delayed (hours)
Severity often dose-dependent
Limited exposure may be tolerated
Examples: Lactose intolerance, gluten intolerance (non-celiac)

Sensitivity (Heightened Response)

Enhanced response without immune involvement
Generally mild symptoms
Often dose-dependent
May improve or worsen over time
Examples: Caffeine sensitivity, chemical sensitivities

Clinical Implications

Reaction Type	Medication Alternatives	Alert Level	Patient Guidance
Allergy	Must avoid entire drug class	High - hard stop	Strict avoidance, carry epinephrine
Intolerance	May try alternatives in class	Medium - warning	Limit exposure, symptom management
Sensitivity	Usually can use with caution	Low - informational	Monitor symptoms, adjust as needed

Use Cases

Allergy Documentation

When recording patient reactions:

Determine if reaction was immune-mediated
Select appropriate reaction type
Document in PatientAllergy record
Set alert level based on reaction type

Medication Decision Support

When prescribing medications:

Check patient's allergies by reaction type
Hard-stop alert for ALLERGY reactions
Warning for INTOLERANCE (may proceed with caution)
Informational note for SENSITIVITY

Patient Education

When counseling patients:

Explain difference between allergy and intolerance
Provide appropriate avoidance guidance
Discuss when epinephrine is needed (allergies only)
Set realistic expectations for intolerances

Cross-Reactivity Assessment

For drug allergies:

Check if true allergy vs intolerance
If allergy, evaluate cross-reactivity risk
Consider alternatives outside drug class
Document decision and reasoning

Related Entities

Entity	Relationship	Description
PatientAllergy	Referenced by	Allergy records that specify reaction type

Standard Values

Code	Label	Description
`ALLERGY`	Allergy	Immune system reaction involving IgE antibodies - can be life-threatening
`INTOLERANCE`	Intolerance	Non-immune adverse reaction to a substance - uncomfortable but not dangerous
`SENSITIVITY`	Sensitivity	Heightened response to a substance without immune involvement - generally mild

3 properties

Schema

Properties

Property	Type	Mode	Description	Required
code	string	stored	Unique code identifying the reaction type Example: `"ALLERGY"`	Required
label	string	stored	Human-readable name of the reaction type Example: `"Allergy"`	Required
description	string	stored	Description of the reaction mechanism	Optional

Examples

Example 1

{
  "@type": "PatientReactionType",
  "code": "ALLERGY",
  "label": "Allergy",
  "description": "Immune system reaction involving IgE antibodies"
}

Example 2

{
  "@type": "PatientReactionType",
  "code": "INTOLERANCE",
  "label": "Intolerance",
  "description": "Non-immune adverse reaction to a substance"
}

Example 3

{
  "@type": "PatientReactionType",
  "code": "SENSITIVITY",
  "label": "Sensitivity",
  "description": "Heightened response to a substance without immune involvement"
}