D69.3
DESCRIPTION
A common bleeding disorder due to immune-mediated destruction of platelets. Clinically apparent associated conditions, drugs (e.g. penicillins, cephalosporins, quinine, rifampicin and heparin), or other agents that may cause thrombocytopenia are NOT present. Patients with suspected ITP should be tested for SLE and for HIV infection.
Investigations
- Thrombocytopenia with normal white cell count and red cell indices (however, anaemia may be present due to blood loss).
- Peripheral blood smear to exclude RBC fragments. Smear may show large platelets.
- Do INR and aPTT, both of which should be normal in ITP.
- If there is a poor response to treatment do a bone marrow aspirate and biopsy.
GENERAL MEASURES
Avoid:
- medication that affects platelet function, e.g. NSAIDs and aspirin,
- platelet transfusions, unless there are life-threatening bleeds,
- dental procedures in acute phase, and
- IM injections.
Reassure the patient that resolution usually occurs in acute ITP.
Medic alert bracelet.
Platelet transfusions may be given if surgery is required or in life-threatening bleeding, discuss with haematologist.
Goal of treatment: to reduce the risk of bleeding, not to normalize the platelet count.
Avoid unnecessary treatment of asymptomatic patients with mild to moderate thrombocytopenia (platelet count >30 x 109 /L).
MEDICINE TREATMENT
Acute ITP
- Prednisone, oral, 1 mg/kg daily, until platelet count has normalised.
- Taper slowly and monitor platelet count. (Refer to PREDNISONE, ORAL for an example of a dose reduction regimen).
- Although prednisone is also indicated for HIV-associated immune thrombocytopenia it is important that all these patients should be fast-tracked for ART.
Second line therapy
Patients with persistent thrombocytopenia not responding to treatment with glucocorticoids.
Treatment with specialist supervision
There are other multiple treatments available but are dependent on specialist opinion.
REFERRAL
- All cases not responding to steroids and, in the case of HIV-infected patients, not responding to ART – discuss with haematologist.
- Refer for second line treatment.
Acute active life-threatening bleeding and surgery
- Platelet transfusions.
Platelet transfusions are only indicated in acute active bleeding uncontrolled by other means or before procedures. In an adult, 1 unit of platelets, preferably single donor, leucocyte depleted platelets, is usually sufficient to control the bleeding initially. Platelet transfusions have limited benefit in this condition as platelets are rapidly destroyed by the immune system.
- Methylprednisolone acetate 1 g, IV, daily for 3 days.
If the bleeding cannot be controlled, consult with a specialist.