Detection of sarcoidosis associated fasciitis by uptake on a FDG PET scan: a novel finding.
We report a case of a sarcoidosis patient with bilateral calf and thigh stiffness who was noted to have intense linear FDG uptake on a PET scan that localized to the fascia of his calves and thighs. His serum creatine kinase level was normal. Fasciitis has rarely been reported to be detected on FDG PET scans, and, to our knowledge, never in a sarcoidosis patient. FDG PET may have a role in identifying fasciitis or myositis when a patient has muscular complaints and no clinical or laboratory evidence of muscle injury.
The internal consistency of PRO fatigue instruments in sarcoidosis: superiority of the PFI over the FAS.
The Fatigue Assessment Scale (FAS) is a 10-item patient reported outcome (PRO) questionnaire that is used to measure fatigue in sarcoidosis. After several months of use, we began to question the reliability of the FAS in our clinic population. Therefore, we administered an additional fatigue PRO, the Patient Reported Outcomes Measurement Information Systems (PROMIS) Fatigue Instrument (PFI). Our hypothesis was that the internal consistency/reliability (Cronbach's alpha) of the PFI would be superior to the FAS in sarcoidosis patients because two of the ten FAS items (items #4 and #10) required reverse scoring (these items were scaled in the opposite direction to the other 8 items).
We found that the PFI had "excellent" consistency in our sarcoidosis clinic. The FAS did not demonstrate the same degree of internal consistency. The Cronbach's estimate of the FAS with items #4 and #10 removed was vastly superior to the FAS. These data support our contention that FAS items #4 and #10 detract from the internal consistency of this PRO. They also suggest that the PFI is superior to the FAS in terms of reliability.