The pigmented purpuric dermatoses (PPDs), also known as capillaritis, purpura simplex, and inflammatory purpura without vasculitis, are a group of chronic, benign, cutaneous eruptions characterized by the presence of petechiae, purpura, and increased skin pigmentation. PPDs most commonly occur on the lower extremities and may be asymptomatic or pruritic.
Familiarity with the clinical and pathologic findings of PPDs is useful for distinguishing them from cutaneous vasculitis and other disorders that may present with similar clinical features. The classic pathologic findings of PPDs include a perivascular mononuclear cell inflammatory infiltrate, erythrocyte extravasation, and hemosiderin deposition.
The diagnosis and treatment of PPDs will be reviewed here. Cutaneous vasculitis is discussed separately. (See "Evaluation of adults with cutaneous lesions of vasculitis" and "Management of adults with idiopathic cutaneous small vessel vasculitis".)
Data are limited on the epidemiology of pigmented purpuric dermatoses (PPDs). Overall, these disorders are considered to be uncommon . The major subtypes of PPD include:
●Schamberg's disease (the most common form of PPD [2,3]; also known as progressive pigmentary purpura)