Calculation of focus score based on biopsy from the lower lip at Sjøgren's syndrome. There must be 2-4 small glands so that the microscopic surface is at least 8 square millimeters (reference: Fisher BA, 2017)
- Small salivary glands are examined in biopsy from the lip
- Number of foci (accumulation) with more than 50 lymphocytes is summarized
- The area being considered is calculated
- Number of foci (n) divided by the surface area (a) is multiplied by 4 = foci score
Formula n: ax 4 =
- Value 1,0 or higher may indicate Sjögren's syndrome, but is not diagnostic.
- Smokers have lower scores than non-smokers.
- For example, false positives occur after injury (bite) on the lip