부산대학교 도서관

Psoriasis is a chronic inflammatory disease mainly involving the skin and joints, mediated by pro-inflammatory cytokine tumor necrosis factor (TNF)-α. In hepatitis C, continuous inflammation mediated by TNF-α leads to liver cirrhosis and diabetes mellitus. Hence, psoriasis and hepatitis C have pathophysiological factors in common. An epidemiological association between the two conditions has been reported, but no detailed research has yet been performed. Frequency of hepatitis C virus (HCV) infection was assessed in 717 patients with psoriasis and 38 057 with all other dermatological diseases who visited Fukuoka University Hospital in 1998–2011. HCV and HCV psoriatic patients were further compared. Frequency of HCV infection was significantly higher in psoriasis (7.5%) than in controls (3.3%) in overall ages. When stratified by age at the first visit, the frequency was significantly higher in patients with psoriasis than in controls aged in their 60s (11.8% vs 6.6%, respectively, P = 0.0215) and 70s (19.5% vs 7.3%, P < 0.0001). HCV psoriatic patients were significantly older at onset than HCV ones (median, 54 vs 39 years), stronger male predominance (male/female ratio, 4.4:1), similar family history of psoriasis, higher association of diabetes mellitus and hypertension, and significantly lower body mass index (22.4 ± 2.73 vs 24.2 ± 4.61), in age-stratified (≥40 years) analysis. HCV psoriatic patients were less obese, but still had a higher frequency of diabetes mellitus and hypertension, possibly due to chronic inflammation in the liver and other organs. HCV infection may trigger psoriasis, especially late-onset psoriasis, possibly via overproduction of TNF-α, a common mediator of the two conditions.