Gangrenous digital infarcts in a severe case of cutaneous polyarteritis nodosa

Cutaneous polyarteritis nodosa (CPAN) is a rare diagnosis which is distinct from polyarteritis nodosa (PAN). PAN is a medium-vessel vasculitis which can affect multiple organs and classically produces microaneurysms in the vasculature. CPAN is limited to the skin mainly affecting small vessels. There is an absence of microaneurysms in CPAN and it does not affect internal organs. However, the histopathological findings on the skin are similar to PAN. CPAN rarely progresses to PAN but relapses more often. We will illustrate a challenging case of a patient with CPAN who developed gangrenous infarcts despite initial immunosuppressive treatment with high-dose steroids and azathioprine. His treatment had to be escalated to intravenous cyclophosphamide which induced disease remission.