SNOMED CT currently has concepts related to the exacerbation of a disorder:
82 concepts with the terming "Exacerbation of X" - these concepts represent the acute increase of severity of signs and symptoms of an existing chronic disease
23 concepts with the terming "Exacerbated by..." - these concepts most often represent the increase of severity of signs and symptoms of an existing chronic disease by another disease.
In both of these cases, the implication is that the increase in severity of disease is an acute phenomenon. Many of these diseases are modeled with a CLINICAL COURSE = "Acute-on-chronic", while others are modeled with CLINICAL COURSE = "Sudden onset and/or short direction".
In trying to determine the relationship between "Acute-on-chronic" vs. "exacerbation", the former concept is used to represent both of the above scenarios, plus the simple overlay of an acute condition on top of an existing chronic condition (i.e. without increase in severity of the chronic condition), while exacerbation (according to medical dictionaries) is used exclusively to represent an increase in severity of an underlying condition. Though definitions do not explicitly use the term "chronic" disease, the implication and the way it has been used in SNOMED is related to chronic conditions, such as asthma or eczema.
https://medical-dictionary.thefreedictionary.com/exacerbation
Exacerbation is a specific subclass of acute-on-chronic and in the case of Asthma, has been divided into three subtypes of mild, moderate, and severe. Thes represent an increase of severity of the condition above the baseline for a diagnosis, thus it is possible to have a mild exacerbation of moderate persistent asthma (i.e a mild increase in severity over the existing moderate disease).
We propose to create four new clinical course concepts under 255212004 |Acute-on-chronic (qualifier value)| to allow for the specific representation of an exacerbation (text definitions to be provided) over the more general acute-on-chronic (text definition to be provided).
Example:
Acute-on-chronic (qualifier value): An acute (sudden and severe) event superimposed on a pre-existing chronic condition. This be either a sudden worsening of a chronic condition itself (an exacerbation) or the development of a new, separate acute illness on top of a chronic disease.
Exacerbation (qualifier value): A sudden worsening of symptoms or an increase in the severity of a chronic disease.
Three subtypes of Exacerbation would also be created to support asthma modeling:
- Mild exacerbation (qualifier value)
- Moderate exacerbation (qualifier value)
- Severe exacerbation (qualifier value)
This proposal allows for the proper modeling of the exacerbation of a chronic disease, but does not address the issue with the severity of the underlying chronic disease itself, e.g. 10675911000119109 |Acute severe exacerbation of mild persistent allergic asthma (disorder)|
Related tickets:
GC-1456 - Getting issue details... STATUS
IHTSDO-1011 - Getting issue details... STATUS
Comments requested.