Skin petechiae are hemorrhagic patchy lesions of the skin and mucous membranes, which are the same in nature as bleeding spots and mostly suggest hematologic disorders or diseases causing bleeding and clotting abnormalities. Common diseases: 1. Epidemic hemorrhagic fever: bleeding spots or petechiae of different sizes can be seen on the oral mucosa, chest and back, and axillae, or bleeding spots in the form of stripes or scratches. 2, thrombocytopenic purpura: petechiae and petechiae can occur in any part of the skin and mucous membranes, but more in the distal extremities. 3.Encephalomyelitis: petechiae and petechiae can be found on the skin and mucous membranes. 4.Sepsis: Various skin injuries can be seen, with petechiae, petechiae, scarlet fever-like rash, and zoonotic rash common. 5.Trauma: dark purple petechiae may appear on the skin after bruising, and for more serious bruises, hematomas may appear. 6, allergic purpura: mostly manifested as skin purpura. The purpura varies in size and can fuse into patches to form petechiae. Purpura is mainly confined to the extremities, especially the lower extremities and buttocks. 7, acute leukemia: more than a number of patients have bleeding, the degree of severity varies, the site can be throughout the body, manifested as petechiae, petechiae, nasal bleeding, gum bleeding and excessive menstruation, fundus bleeding, etc.