When creating a lateralized disorder concept, two concepts should be created:
concept for the left side
concept for the right side
Descriptions
FSN: <morphologic abnormality> of <right/left> <body structure> (disorder)
PT: Right/left
For example, 1089071000119109 |Inflammation of left mastoid (disorder)|
FSN: Inflammation of left mastoid (disorder)
PT: Left mastoiditis
When creating a lateralized disorder concept, if a non-lateralized parent does not exist, then it should be created as well. In other words, do not just create the right and left versions, but also create a concept to represent the laterality-agnostic parent.
For example,
When creating Inflammation of left mastoid and Inflammation of right mastoid, also ensure a concept for Inflammation of mastoid exists.
Where the disorder is left/right of a specific anatomical site, and the preferred term naming pattern of Right/left causes a combination that does not sound like natural flowing English, the guidance above can be circumvented. See the section and Laterality section .
For example,
Left interphalangeal thumb joint open traumatic dislocation should follow naming guidance of Open traumatic dislocation of interphalangeal joint of left thumb.
Left abscess of foot is an incorrect term; instead, this should read Abscess of left foot.
Where the bilateral disorder description causes a combination that does not sound like natural flowing English, the guidance below can be circumvented.
FSN: of bilateral (disorder)
PT: Bilateral
SYN: of bilateral
SYN: of both
FSN: of bilateral (disorder)
PT: of bilateral
SYN: of both
Note the PT of Bilateral is not required. Bilateral is to describe the body site, not the morphologic abnormality.
For example, 15725081000119100 | Effusion of joint of bilateral feet (disorder) |
FSN: Effusion of joint of bilateral feet (disorder)
PT: Effusion of joint of bilateral feet
SYN: Effusion of joint of both feet
Also note that joint is singular. This is to denote that the joint may be singular on each side of the body; the plurality of feet will represent the laterality. Using joints as plural may incorrectly reflect that there are multiple joints affected in both feet.
Bilateral disorders should be modeled using two relationship groups, one for each lateralized body structure.
For example, 1084011000119100 |Inflammation of bilateral mastoids (disorder)|
FSN: Inflammation of bilateral mastoids (disorder)
PT: Bilateral mastoiditis
SYN: Inflammation of bilateral mastoids
SYN: Inflammation of both mastoids

