Diffuse dermal angiomatosis is a form of cutaneous reactive angiomatosis characterized clinically by painful erythematous or violaceous lesions with ulcers that may mimic cutaneous vasculitis/vasculopathy. Histologically it shows a benign, diffuse proliferation of endothelial cells with tiny blood vessels in the papillary and reticular dermis. Herein, we report four patients with diffuse dermal angiomatosis in the setting of calciphylaxis and monoclonal gammopathy and review the cases previously published in the literature. Comorbidities and management will also be discussed.