Causes and risk factors
Purpura is caused due to bleeding from the small capillaries underneath the skin. Purpura can be platelet dependent, i.e., low platelet count [thrombocytopenic] or platelet independent [nonthrombocytopenic]. It can be congenital or acquired. Acquired nonthrombocytopenic conditions like allergies, drug induced, and trauma are some of the causes. Thrombocytopenic conditions such as bone marrow failure, coagulation disorders, or excessive destruction of platelets are other causes. Factors that can cause bleeding underneath the skin are primary thrombocytopenic purpura, secondary thrombocytopenic purpura, vitamin C deficiency [scurvy], vasculitis, typhus infection, meningitis, septicemia, disseminated intravascular coagulation, meningococcemia. Hypertension can cause purpura. It can also occur due to post-transfusion purpura after radiation treatment, etc.
Clinical presentation
Patient presents with red-purple skin discoloration present on extremities, oral mucosa. Bruising or ecchymoses can occur in the deeper tissues. There is bleeding under the skin. Tiny red spots are seen which may fade away or become dark brown in color. This does not blanch on applying pressure.
Investigations
Medical history by the patient and clinical examination by the dermatologist helps in diagnosis. Routine blood tests are done. Platelet count is done. Coagulation studies or assays and other tests to rule out connective tissue disorders are done. Skin biopsy may be recommended.
Treatment
Treatment depends upon the underlying cause. The underlying cause must be treated. Intensive treatment is initiated if platelet count is less than 20000 per mm3.
Complications
Complications such as coagulation anomalies, permanent skin discoloration may occur.
When to Contact a Doctor
In case there is an appearance of a skin rash, one must consult a doctor.
Systems involved
Cardiovascular system, integumentary system
Organs involved
Skin, capillaries
