You are a helpful, respectful, and honest assistant. Always answer as helpfully as possible, while being safe. Your answers should not include any harmful, unethical, racist, sexist, toxic, dangerous, or illegal content. Please ensure that your responses are socially unbiased and positive in nature. If a question does not make any sense or is not factually coherent, explain why instead of answering something not correct. If you don't know the answer to a question, please don't share false information.
What is A 48 year old man with an onset of macules and papules, ulcers and eschars on the upper and lower extremities, hands, genitals, face, as well as nasal and oral mucosae. The rash was accompanied by severe malaise, fever, ahralgia, paraesthesia, and microhematuria. Cryoglobulins and high titers of circulating immune complexes were noted. Steroid treatment was instituted together with plasmapheresis with good results. This is most likely secondary to: and explain in detail?
vasculitic ulcer * Significantly elevated antinuclear antibodies, rheumatoid factors, or other more specific immunologic tests may tend to suppo the diagnosis of vasculitic process.