Most common pattern and not specific for any one disease but is most often suggestive of a hypersensitivity disorder . Epidermal changes and predominate type of leukocyte present may aid in differential. Leukocytes marginated in blood vessels and aggregated around vessels.
Vessels have perivascular accumulation of lymphocytes, macrophages, plasma cells.
Dermis may be fibrotic. Epidermis is hyperplastic. If the condition is acute, we would expect grossly detectable edema and hyperemia. If chronic, we may see nonspecific changes of a chronic hyperplastic dermatitis, such as thickened, hyperkeratotic, hyperpigmented skin. Since this pattern is so generic, we must be careful to evaluate concurrent changes present to help with the differential diagnosis.