Emergency Medicine

SKIN DISORDERS

General Medical Emergencies 115

• lymphoproliferative disorders


• hypersplenism.
  (b) abnormal marrow:


• leukaemia


• lymphoma


• myeloid metaplasia.
  (ii) Thrombocytopenia, without splenomegaly:
  (a) normal marrow:


• immune: idiopathic thrombocytopenic purpura (ITP),
  drugs, infections including HIV


• non-immune: vasculitis, sepsis, disseminated intravascular
  coagulation (DIC), haemolytic–uraemic syndrome (HUS),
  thrombotic thrombocytopenic purpura (TTP).
  (b) abnormal marrow:


• aplasia, fibrosis or infiltration


• cytotoxics


• alcohol, thiazides.
  (iii) Non-thrombocytopenic:
  (a) cutaneous disorders:


• trauma, sun


• steroids, old age.
  (b) systemic disorders:


• uraemia


• von Willebrand’s disease


• scurvy, amyloid.

3 Causes of pa lpable purpura include:
(i) Vasculitis:
(a) polyarteritis nodosa
(b) leucocytoclastic (allergic), Henoch–Schönlein purpura.
(ii) Emboli:
(a) meningococcaemia
(b) gonococcaemia
(c) other infections: Staphylococcus, Rickettsia (Rocky Mountain
spotted fever), enteroviruses.

4 Ask about any drugs taken, systemic symptoms, bleeding tendency, travel
history, alcohol use and HIV disease or risk behaviour.

5 Check the temperature, pulse, blood pressure, SaO 2 and examine for
lymphadenopathy and hepatosplenomegaly. Perform a urinalysis for casts.

6 Send blood for FBC and film, coagulation profile, ELFTs and blood cultures
according to the likely aetiology.