Purpura

Question 1

Probability diagnosis

Answer 1

Simple purpura (easy bruising syndrome)

Senile purpura

Corticosteroid-induced purpura

Immune thrombocytopenic purpura

Henoch–Schönlein purpura

Question 2

Serious disorders not to be missed

Answer 2

Malignant disease:

• leukaemia
• myeloma

Aplastic anaemia

Myelofibrosis

Infection:

• septicaemia
• meningococcal infection
• infective endocarditis
• measles
• typhoid
• dengue/chikungunya
• other tropical haemorrhagic viral infections

Disseminated intravascular coagulation

Thrombotic thrombocytopenic purpura

Fat embolism

Kidney failure

Question 3

Pitfalls (often missed)

Answer 3

• Haemophilia A, B
• von Willebrand disease (vW)
• Post-transfusion purpura
• Trauma (e.g. domestic violence, child abuse)

Rarities:

• hereditary telangiectasia (Osler–Weber–Rendu syndrome)
• Ehlers–Danlos syndrome
• scurvy
• Fanconi syndrome

Question 4

Masquerades checklist

Answer 4

Drugs:

• chloramphenicol
• corticosteroids
• sulphonamides
• quinine/quinidine
• thiazide diuretics
• NSAIDs
• cytotoxics
• oral anticoagulants/heparin

Anaemia:

• aplastic anaemia

Question 5

Psychogenic factors

Answer 5

Factitious purpura (intentionally pinching skin)

Question 6

Key history

Answer 6

Include family and drug history

Features of the purpura such as;

• post trauma or spontaneous
• recurrent episodes of bleeding
• whether any bleeding is out of proportion to the trauma

Question 7

Key examination

Answer 7

Detailed examination of the;

• skin
• lips and oral mucosa
• lymph node areas
• abd exam with emphasis on spleen and liver

Urinalysis searching for blood (microscopic or macroscopic)

Question 8

Key investigations

Answer 8

FBE and blood film

If coagulation defect suspected:

• • prothrombin time (PT) i.e. INR
• • activated partial thromboplastin time (APTT)
• • fibrinogen level
• • thrombin time (TT)

If platelet pathology suspected:

• • platelet count
• • platelet function analyser (PFA-100).

If inherited disorders suspected:

• • factor VIII
• • vW factory activity
• • vW factor antigen.

The FBE and blood film is useful in pinpointing the aetiology.

Other special tests such as von Willebrand screen and PFA-100 can be advised by the consultant.

The bone marrow examination is useful to exclude the secondary causes of thrombocytopenia, such as leukaemia, other marrow infiltrations and aplastic anaemia.

Question 9

Diagnostic tips

Answer 9

The routine screening tests for the investigation of pts with bleeding disorders can be normal despite the presence of a severe haemorrhagic state

Platelet abnormalities present as early bleeding following trauma.

Coagulation factor deficiencies present with delayed bleeding after initial haemostasis is achieved by normal platelets.

A normal response to previous coagulation stresses (e.g. dental extraction, circumcision or pregnancy) indicates an acquired problem.

If acquired, look for evidence of MILD:

• Malignancy
• Infection
• Liver disease
• Drugs