Subclinical systemic and vascular inflammation detected by 18F‐fluorodeoxyglucose positron emission tomography/computed tomography in patients with mild psoriasis

Severe psoriasis is a systemic inflammatory disease involving major arteries and internal organs. The association between psoriasis and arterial inflammation, however, has been noted mostly in patients with moderate to severe psoriasis. Therefore, it is still not clear whether mild psoriasis also increases the arterial inflammation and cardiovascular disease. In this study, we aimed to investigate systemic inflammation using ¹⁸F‐fluorodeoxyglucose positron emission tomography/computed tomography (FDG‐PET/CT) in patients with mild psoriasis. In a nested case–control study, FDG‐PET/CT findings of 10 patients with mild chronic plaque psoriasis involving a body surface area of less than 5% were compared with those of 10 age‐ and sex‐matched healthy controls. The degree of FDG uptake in the large arteries (ascending aorta, aortic arch, descending aorta, suprarenal abdominal aorta and infrarenal abdominal aorta,) and liver were analyzed using the maximum target‐to‐background ratios (TBR). There were no significant demographic differences between the psoriasis patients and the control subjects (P > 0.05). Patients with psoriasis showed higher maximum TBR than healthy controls in all examined arterial segments, with statistical significance reached in the suprarenal abdominal aorta (P < 0.05), ascending thoracic aorta (P < 0.01) and infrarenal abdominal aorta (P < 0.05), and in the liver (P < 0.05). The “candy cane sign”, which represents typical arterial inflammation of the thoracic aorta, was noted upon PET in the majority of psoriasis cases. In conclusion, mild psoriasis is also associated with arterial and hepatic inflammation, which can be readily demonstrated by using FDG‐PET/CT.