I THINK YOU ARE A PATIENT OF ITP
The defining characteristics of petechiae and purpura in thrombocytopenic patients are that they are asymptomatic and not palpable. This is an important clinical distinction from patients with vasculitis
, such as Henoch-Schönlein purpura or drug hypersensitivity
. In vasculitic purpura, the patient experiences a prodrome of stinging or burning. On examination, vasculitic purpura has a palpable, papular character.
and vasculitic purpura also have a different pattern of distribution. Thrombocytopenic purpura is consistently localized to dependent portions of the body. As a result, petechiae are most dense on the feet and ankles, fewer are present on the legs, and only scattered petechiae occur elsewhere on the body. Areas with firm subcutaneous tissue
, such as the soles of the feet, are protected from petechiae, while areas with minimal subcutaneous support, such as the oral mucosa
and conjunctivae, may have large bullous appearing hemorrhages. In contrast, vasculitic purpura may occur in symmetrical patches without regard for a dependent distribution