Henry Weightman Stelwagon, Essentials of Diseases of the Skin
“ State the etiology of purpura.In most instances no cause can be assigned. The disease occurs at all ages from childhood to advanced life, and in individuals, apparently, in good and bad health alike. The hemorrhagic type is oftener seen in subjects debilitated or in a depraved state of health. A microörganism is also looked upon as a factor by some observers, especially in the grave type of disease. ”
