Purpura

What is purpura?

Purpura is the name given to the discolouration of the skin or mucous membranes due to haemorrhage from small blood vessels.

• Petechiae are small, purpuric lesions up to 2mm across
• Ecchymoses or bruises are larger extravasations of blood.
• Palpable purpura is purpura than can be felt, due to inflammation of the blood vessels (vasculitis)
• Pigmented purpura is a sign of petechial haemorrhages associated with capillaritis

Extravasated blood usually breaks down and changes colour over a few weeks from purple, orange, brown and even blue and green.

Classification of purpura

There are many different types of purpura. Their classification depends on the appearance or cause of the condition.

What are the signs and symptoms of purpura?

The signs and symptoms of purpura vary according to the type of purpura. The following broad generalisations may be made.

• Petechiae are usually present in thrombocytopaenic purpura. There may be some external bleeding and bruising.
• Coagulation defects usually present as large ecchymoses and external bleeding. Petechiae do not feature.
• Inflamed blood vessels (vasculitis) cause persistent and localised purpura with an erythematous inflammatory component. This may be palpable. Ecchymoses and external bleeding are uncommon.

Suction bruise 

Injury 

Venous stasis 

Vasculitis 

Steroid purpura 

Disseminated intravascular coagulation 

What is the treatment for purpura?

The underlying cause of purpura should be identified and treated accordingly.