Palpable petechiae and<unk>  are a result of either perivascular inflammation (vasculitis) or infection.
Non-palpable petechiae usually occur in low platelet states such as ITP and DIC
Fever
Toxic appearance
Hypotension
Mucosal lesions
Severe pain
Very old or young age
Immunosuppressed
New medication
Purpura
Abnormal platelet count and/or coagulation
Seabather's eruption
Septicemia
Black hairy tongue
Idiopathic thrombocytopenic purpura 
Paronychia
Hemolytic uremic syndrome