S4C6VA1VisualAids

Vasculitic Patterns

1. perivenular component in the reticular dermis

2. collagenosis (interstitial infiltrates of lymphoid cells and a variable component of mucinosis)

a. migration of cells from perivascular spaces into the reticular dermis among collagen bundles

b. leukocytoclasia (+/-)

c. extravasation of rbc’s (+/-)

d. vascular necrosis and thrombosis (+/-)

3. variable epidermal changes but often the epidermis is univolved

S4C6VA1-1: The table presents a brief summary of the general features of vasculitic processes in the skin. The complex of features does not exclude a lymphocytic variant (except by fiat).

S4C6VA1-2: Patterns of lymphocytic vasculitides are illustrated. Obviously, the features overlap, on one hand, with those of the so-called lymphocytic infiltrates of the dermis and, on the other, with those of the common dermatitides. Erythema annulare centrifugum, polymorphic light eruption, and lymphocytic infiltrate of Jessner can all be accommodated in the relevant parcels of virtual images. Classically, epidermal involvement is not a feature, but this restriction may, in part, be dependent on the representation of variations in regional surface topography.

S4C6VA1-3: There is utility in a concept that combines the histologic features of the lymphocytic infiltrates (vasculitides) with the features of some of the cell-rich and cell-poor lichenoid reactions. Such combinations qualify as lichenoid-lymphocytic vasculitides.

Lichenoid Lymphocytic Vasculitis

1. vasculitic patterns in reticular dermis

2. cell-rich or cell-poor lichenoid patterns at the dermal-epidermal interface (a variable feature)

3. distinctions among representatives are based on patterns of epidermal kinetics, or cell types in infiltrates (i.e., high component of histiocytes and plasma cells in lesions of secondary lues; the patterns of whorled transepidermal elimination in the erythema multiforme-like complex; the extensive infiltration of the basal unit by lymphocytes and histiocytes in the pityriasis lichenoides-like disorders; and the lysis of the basal unit with clusters of necrotic keratinocytes and with erosion of rete ridges to produce “saw-tooth” patterns in the lichen planus-like disorders)

S4C6VA1-4: For some disorders, the patterns of a lichenoid reaction are combined with perivenular infiltrates in the reticular dermis. Examples include the lupus erythematosus-like disorders, the erythema multiforme-like disorders, the pityriasis lichenoides-like disorders, and the lichen planus-like disorders.

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