[Vasculitis with associated skin changes and dermatitis with associated vasculitis].
By applying strict diagnostic criteria and a standardized classification (Chapel Hill 1994) an attempt has been made to shed some light on the varying and sometimes puzzling information concerning the quantity and quality of skin lesions with systemic vasculitis or vasculitis associated with certain types of dermatitis. It has to be emphasized that associated skin lesions are hereby non-specific. However, a palpable purpura with a predeliction for the lower extremities is considered to be quite typical. The same diagnostic criteria as for systemic vasculitis should also be applied to dermatitis with associated vasculitis. It also has to be stressed that not all patients with a certain type of dermatitis necessarily show a vasculitis. However, if present, an associated vasculitis does not always involve all blood vessels, therefore it may not show up in each histological section examined. The gold standard of diagnosis of a vasculitis is a biopsy with hematoxylin staining and in additional van Gieson-elastica staining may be helpful. According to actual experience gained since their introduction, immunohistochemical and immunological methods play only a supportive role.