Purpura

Keywords: Petechiae

Causes

Appropriate Tests

 

Clinical assessment; Full blood count, Blood film, Platelet count.

Further investigation is unlikely to be productive unless there are clinical features suggestive of vasculitis or there is a personal or family history suggestive of a bleeding disorder.

The skin bleeding time and Hess test are neither sensitive nor specific and are not appropriate.

Renal function, autoAb profile, inflammatory markers.

Thrombocytopenia

 

Vasculitis, especially

  • Henoch-Schönlein purpura

 

'Senile purpura'

  • Elderly patient
  • Prolonged solar exposure
  • Corticosteroid excess

Usually seen in older, fair skinned patients who have had prolonged solar exposure, with purpura typically on the forearms and dorsa of hands.


See Cushing's syndrome

Scurvy

Vitamin C level

Porphyria cutanea tarda

Not a true form of purpura but may sometimes be confused with it. The lesions are typically blistering and heal with scarring.