Bar code reader – an algorithmic approach to cutaneous occluding vasculopathies? Part I: small vessel vasculopathies

AIMS: The classifications of occluding vasculopathies may present some difficulties. Firstly, classifications may follow different principles, e.g. clinicopathological findings, etiology or pathomechanism. Secondly, authors sometimes do not distinguish between vasculitis and vasculopathy. Thirdly, vasculopathies are often systemic diseases. Organ‐specific variations make morphologic findings difficult to compare. Moreover, subtle changes may be recognized in the skin, but be invisible in other organs. Our aim was to use the skin and subcutis as tools and clinicopathological correlation as the basic process for classification. METHODS AND RESULTS: In the first step, we differentiate between small and medium vessel occluding vasculopathies in the skin, and focus in this part on small vessel occluding vasculopathies. In the second step, we differentiate among subtypes of small vessels. In the final step, we differentiate according to the time point of the coagulation/reorganization process and the involved inflammatory cells/stromal features. Applying the same procedure to the various entities and visualizing the findings with bar codes makes the similarities and differences more apparent, both clinically and with histopathology. CONCLUSION: Occluding vasculopathies are often not separate entities, but reaction patterns and epiphenomena. Distinguishing them from vasculitides is crucial because of differences in pathogenesis, therapeutic approach and prognosis.