pigmented purpuric dermatosis pigmented purpuric dermatosis pigmented purpuric dermatosis refers to one of the three major classes of skin conditions characterized by purpuric skin eruptions. pigmented purpuric dermatosisother namesprogressive pigmentary dermatosis, purpura pigmentosa chronica, pigmentary purpuric eruptions, or progressive pigmenting purpura or schamberg's diseasespecialtydermatology pigmented purpuric dermatosis are distinguished from other purpura by size (0.3–1 cm) and are most often seen in the lower extremities.: 829 pigmentary purpuric eruptions may present with one of several clinical patterns. there may be overlapping characteristics among pigmented purpuric dermatosis and between their signs and those of other purpuric eruptions.: 829 examples of the pigmented purpuric dermatosis group include:: 829–30 schamberg's disease majocchi's disease (purpura annularis telangiectodes) gougerot-blum syndrome (pigmented purpuric lichenoid dermatitis) ducas and kapetanakis pigmented purpura lichen aureus although vascular damage may be present, it is insufficient for these conditions to be considered forms of vasculitis. a few very small non-blinded studies of treatment with narrow-band ultraviolet light have been reported as promising.