Cutaneous collagenous vasculopathy: Report of first Japanese case and review of the literature.

Cutaneous collagenous vasculopathy (CCV) is a rare acquired idiopathic microangiopathy characterised by the progressive development of diffuse asymptomatic telangiectasias over the skin. Histologically, the presence of a thick hyaline collagenous wall around the affected capillaries, comprising the accumulation of collagen type IV, is noted. We herein report the case of a 17-year-old Japanese boy with symmetrical patches of diffuse telangiectasias on the bilateral extremities that persisted for 10 months. A histological examination revealed dilated capillaries in the papillary dermis surrounded by thick perivascular deposition of hyaline-like materials, which stained positive for periodic acid-Schiff and collagen type IV. We additionally performed a review of 26 CCV patients previously reported in the English literature and summarised the clinical and histological features of generalised telangiectatic disorders, such as CCV, generalised essential telangiectasia and hereditary haemorrhagic telangiectasia. To establish an accurate diagnosis, it is important for dermatologists to recognise the clinical and histological characteristics of CCV and the importance of the histological analysis.