Although trigeminal neuralgia (TN) has been associated with systemic sclerosis (SSc), there is a paucity of evidence and pathophysiological processes remain unknown. We undertook a nested case-control study to identify associations between TN and SSc in a large multi-centered cohort and identify possible pathophysiological links.
Data were derived from a longitudinal cohort of 1652 SSc subjects. Cases with a physician-reported diagnosis of TN were identified at baseline visit (prevalent) and during follow-up (incident). Each case was matched on study visit to four SSc patients without TN. Sociodemographic, clinical and serological characteristics of cases and controls were compared.
At enrolment, 43/1652 (2.6%) subjects had a history of TN. During follow-up, an additional 36 subjects developed TN over 6193 person-years of observation (incidence rate 5.8 per 1000 person-years). Cases were identified and matched to 172 and 144 controls, respectively. Compared to controls, prevalent cases had more inflammatory myositis (24.4% versus 5.2%, p<0.001) and inflammatory arthritis (46.5% versus 30.2%, p = 0.043). Incident cases also had more inflammatory myositis (19.4% versus. 6.3%, p = 0.033) and inflammatory arthritis (50.0% versus. 16.2%, p<0.001) compared to controls. There was a trend towards more interstitial lung disease in prevalent (32.6% versus 23.8%, p = 0.241) and incident (55.6% versus 40.6%, p = 0.105) cases compared to controls.
This study provides novel evidence for a clinical association linking TN, inflammatory myositis, inflammatory arthritis and possibly interstitial lung disease. In addition to ischemia, we propose that TN in SSc could also be a consequence of inflammatory and possibly fibrotic processes.