Frequency
United States
The incidence of ITP in adults is approximately 66 cases per 1,000,000 per year.
An average estimate of the incidence in children is 50 cases per 1,000,000 per year.
New cases of chronic refractory ITP comprise approximately 10 cases per
1,000,000 per year.
International
According to studies in Denmark and England, childhood ITP occurs in
approximately 10-40 cases per 1,000,000 per year. A study in Kuwait reported a
higher incidence of 125 cases per 1,000,000 per year.
Mortality/Morbidity
Hemorrhage represents the most serious complication; intracranial hemorrhage is
the most significant. The mortality rate from hemorrhage is approximately 1% in
children and 5% in adults. In patients with severe thrombocytopenia, predicted 5-
year mortality rates from bleeding are significantly raised in patients older than 60
years versus patients younger than 40 years, 47.8% versus 2.2%, respectively.
Older age and previous history of hemorrhage increase the risk of severe bleeding
in adult ITP.
Spontaneous remission occurs in more than 80% of cases in children but is
uncommon in adults.
Sex
In chronic ITP (adults), the female-to-male ratio is 2.6:1. More than 72% of
patients older than 10 years are female.
In acute ITP (children), distribution is equal between males (52%) and females
(48%).
Age
Peak prevalence occurs in adults aged 20-50 years.
Peak prevalence occurs in children aged 2-4 years.
Approximately 40% of all patients are younger than 10 years.
History
Focus on the symptoms of bleeding (eg, type, severity, duration) and on symptoms
that may exclude other causes of thrombocytopenia.
Elicit risk factors for HIV and systemic symptoms linked to other illnesses or to
medications (eg, heparin, alcohol, quinidine/quinine, sulfonamides) that may cause
thrombocytopenia. Medications can be a common etiology for inducing
thrombocytopenia, and patients should have their medications carefully reviewed.
One study used 3 distinct methods to document drugs that may be associated with
drug-induced immune thrombocytopenia (DITP).
[1, 2]
Approximately 1500 drugs
are associated with thrombocytopenia, but, using this analysis, 24 drugs had
evidence of causing thrombocytopenia by all 3 methods.
Address risk factors for increased bleeding, such as GI disease, CNS disease,
urologic disease, or active lifestyle, as these may determine the aggressiveness of
management.
Common signs, symptoms, and precipitating factors include the following:
o
Abrupt onset (childhood ITP)
o
Gradual onset (adult ITP)
o
Purpura
o
Menorrhagia
o
Epistaxis
o
Gingival bleeding
o
Recent live virus immunization (childhood ITP)
o
Recent viral illness (childhood ITP)
o
Bruising tendency
Limited data are available on the recurrent form of the disease. One study showed
a 6% prevalence of recurrent ITP with most patients (69%) having only one
recurrence. Though one third of patients had their recurrent episode within 3
months of their initial one, the remainder of patients had at least a 3-month interval
between episodes.
Physical
Evaluate the type and the severity of bleeding and try to exclude other causes of
bleeding. Seek evidence of liver disease, thrombosis, autoimmune diseases (eg,
nephritis, cutaneous vasculitis, arthritis), and infection, particularly HIV.
Common physical findings include the following:
Nonpalpable petechiae, which mostly occur in dependent regions
Hemorrhagic bullae on mucous membranes
Purpura
Gingival bleeding
Signs of GI bleeding
Menometrorrhagia, menorrhagia
Retinal hemorrhages
Evidence of intracranial hemorrhage, with possible neurologic symptoms
Nonpalpable spleen: The prevalence of palpable spleen in patients with ITP is
approximately the same as that in the non-ITP population (ie, 3% in adults, 12% in
children).
Spontaneous bleeding when platelet count is less than 20,000/mm
3
.
Causes
Immunoglobulin G (IgG) autoantibodies on the platelet surface
Differential Diagnoses
Disseminated Intravascular Coagulation
HIV Infection and AIDS
Thrombocytopenic Purpura
Laboratory Studies
CBC
o
Isolated thrombocytopenia is the key finding regarding laboratory evaluation.
o
Truly giant platelets on peripheral smear suggest congenital thrombocytopenia.
o
The WBC count and hemoglobin typically are normal, unless severe hemorrhage
has occurred.
Coagulation studies are normal, and a bleeding time is not useful.
Imaging Studies
A CT scan of the head is warranted if concern exists regarding intracranial
hemorrhage.
Prehospital Care
Prehospital care focuses on the ABCs, which include providing oxygen,
controlling severe hemorrhage, and initiating intravenous (IV) fluids to maintain
hemodynamic stability.
Prehospital airway control may be necessary for a large intracranial hemorrhage.
EMS providers should be aware of the potential for serious bleeding complications
in patients with idiopathic thrombocytopenic purpura (ITP).
Emergency Department Care
Life-threatening bleeding requires conventional critical care interventions.
In the patient with known ITP, high-dose parenteral glucocorticoids and IV
immunoglobulin (IVIg), with or without platelet transfusions, are appropriate.
Platelet transfusion is indicated for controlling severe hemorrhage. Send a blood
specimen to the lab for type and screen in case platelet transfusion is necessary.
Platelet survival is increased if the platelets are transfused immediately after IVIg
infusion.
A consultation with a hematologist may be required to make a decision regarding
the transfusion of platelets.
Guidelines for transfusion dosage
o
6-8 U of platelet concentrate, or 1 U/10 kg
o
1 U of platelets to increase count of a 70-kg adult by 5-10,000/mm
3
and an 18-kg
child by 20,000/mm
3
Splenectomy is reserved for patients in whom medical therapy fails. Emergent
splenectomy is indicated in patients with life-threatening bleeding in whom
medical therapy fails.
In patients without life-threatening complications, focus ED care on confirming the
diagnosis, if possible, and initiating therapy as needed.
Most patients with undiagnosed thrombocytopenia and purpura will need
admission for further evaluation and treatment, since ITP is a diagnosis of
exclusion.
Consultations
Consult a hematologist for assistance in confirming the diagnosis or, in the patient
with known ITP, arranging disposition and follow-up care, if appropriate.
Consult a neurosurgeon for intracranial hemorrhage. Consultation by other surgical
specialists may be required for extensive hemorrhage at other sites.
Medication Summary
Glucocorticoids and IVIg are the mainstays of medical therapy. Indications for use,
dosage, and route of administration are based on the patient's clinical condition, the
absolute platelet count, and the degree of symptoms. Consultation with a
hematologist may be needed prior to starting therapy.
Children who have platelet counts >30,000/mm
3
and are asymptomatic or have
only minor purpura do not require routine treatment. Children who have platelet
counts < 20,000/mm
3
and significant mucous membrane bleeding and those who
have platelet counts < 10,000/mm
3
and minor purpura should receive specific
treatment.
Adults with platelet counts >50,000/mm
3
do not require treatment. Treatment is
indicated for adults with counts < 50,000/mm
3
with significant mucous membrane
bleeding. Treatment also is indicated for those adults with risk factors for bleeding
(eg, hypertension, peptic ulcer disease, vigorous lifestyle) and in patients with a
platelet count < 20,000-30,000/mm
3
.
IV anti-(Rh)D, also known as IV Rh immune globulin (IG), was not recommended
by the 1996 American Society of Hematology practice guidelines. However, recent
studies using higher dosages of IV RhIG in acute ITP in children and adults show
platelet count increases at 24 hours faster than medicating with steroids and at 72
hours similar to IVIg. Although generally less toxic than IV steroids, IV RhIG is
more expensive than IV steroids. Studies in children with chronic ITP show that
escalating or elevated doses of IV RhIG have comparable responses to those of
high-dose IVIg therapy in children. This therapy is not appropriate for patients who
have undergone splenectomy. Acute intravascular hemolysis after infusing IV
RhIG has been reported, with an estimated incidence of 1 in 1115 patients.
Steroid use and immunosuppressives and splenectomy may be undesirable because
of their associated complications. For long-term steroid use, this includes
osteoporosis, glaucoma, cataracts, loss of muscle mass, and an increased risk of
infection. For immunosuppressive therapy and splenectomy, risks include
worsening immunosuppression and infection or sepsis. Studies of the use of
multiagent therapies in refractory patients are ongoing. Some small studies have
shown limited success. According to one study, using a combination of weekly
vincristine, weekly methylprednisolone, both until platelet counts reached
50,000/mm
3
, and cyclosporine orally twice daily until the platelet count is normal
for 3-6 months seems promising, though larger prospective studies are needed.
Other therapies, such as cyclophosphamide, danazol, dapsone, interferon alfa,
azathioprine, vinca alkaloids, accessory splenectomy, and splenic radiation have
been studied. Many case series discussing these treatments are too small to show
sufficient evidence of a clinically significant reduction in bleeding or mortality
rate; however, they serve as additional therapeutic measures in ITP refractory-to-
primary therapy (eg, glucocorticoids, IVIg immunoglobulin, splenectomy). Newer
studies on rituximab suggest that this agent is an effective treatment option in
splenectomized refractory or relapsed ITP patients.
Clinical trials have shown promise for agents that directly stimulate platelet
production, such as thrombopoietin (TPO) receptor-binding agents. Two new
agents, eltrombopag and romiplostim, are available to patients with chronic ITP
who have failed other therapies.
Both of these agents require registration in a
database. While they show promise for raising platelet counts, there are potential
safety concerns such as thrombocytosis and rebound thrombocytopenia. It is
unlikely that emergency physicians should be prescribing these agents without
being under the recommendation of a hematologist.
Glucocorticoids
Class Summary
These agents are used to treat idiopathic and acquired autoimmune disorders. They
have been shown to increase platelet count in ITP.
Prednisone (Deltasone, Orasone, Sterapred)
Useful in treating inflammatory and allergic reactions; may decrease inflammation
by reversing increased capillary permeability and suppressing PMN activity. DOC
for all adult patients with platelet counts < 50,000/mm
3
. Asymptomatic patients
with platelet counts >20,000/mm
3
, or patients with counts 30,000-50,000/mm
3
with
only minor purpura, may not need therapy; withholding medical therapy may be
appropriate for asymptomatic patients, regardless of count.
Methylprednisolone (Solu-Medrol, Depo-Medrol)
Decreases inflammation by suppressing migration of polymorphonuclear
leukocytes and reversing increased permeability. Used as alternative glucocorticoid
of choice for all patients with severe, life-threatening bleeding or children with
platelet counts < 30,000/mm
3
. Careful observation without medical treatment may
be appropriate in some asymptomatic children.
Blood products
Class Summary
Administration of IVIg may temporarily increase platelet counts in some children
and adults with ITP. Consider IVIg if the situation requires a rapid, temporary rise
in platelet count.
Intravenous immune globulin (IVIg)
DOC for severe, life-threatening bleeding or for children with platelet counts <
20,000/mm
3
with minor purpura; can be used alone or in addition to glucocorticoid
therapy.
Thrombopoietic Agent
Class Summary
These agents directly stimulates bone marrow platelet production.
Eltrombopag (Promacta)
Oral thrombopoietin (TPO) receptor agonist. Interacts with transmembrane domain
of human TPO receptor and induces megakaryocyte proliferation and
differentiation from bone marrow progenitor cells. Indicated for thrombocytopenia
associated with chronic idiopathic thrombocytopenic purpura in patients
experiencing inadequate response to corticosteroids, immunoglobulins, or
splenectomy. Not for use to normalize platelet counts but used when clinical
condition increases bleeding risk.
Prescribers must enroll in Promacta Cares program. Only available through
restricted distribution program. Program phone number is (877) 9-PROMACTA
(877-977-6622).
Romiplostim (Nplate)
An Fc-peptide fusion protein (peptibody) that increases platelet production through
binding and activation of the thrombopoietin (TPO) receptor, a mechanism similar
to endogenous TPO. Indicated for chronic immune (idiopathic) thrombocytopenic
purpura in patients who have had an insufficient response to corticosteroids,
immunoglobulins, or splenectomy.
Only available through the Nplate NEXUS (Network of Experts Understanding
and Supporting Nplate) program, a program designed to promote informed risk-
benefit decisions before initiating treatment.
Further Inpatient Care
Rule out other potential causes of thrombocytopenia.
Emergency splenectomy may be necessary if severe bleeding complications due to
thrombocytopenia do not respond to medical therapy.
Observe for life-threatening bleeding.
Consult with a hematologist, as further treatments (eg, steroids, IVIg, platelet
transfusion) may be indicated.
Further Outpatient Care
Close follow-up care with a hematologist is required.
Elective splenectomy may be necessary if medical therapy fails.
Transfer
Transfer may be necessary under the following conditions:
A hematologist is not available.
Blood bank support is insufficient.
A higher level of intensive care is needed.
Complications
Complications of idiopathic thrombocytopenic purpura may include the following:
Intracranial or other major hemorrhage
Severe blood loss
Adverse effects of corticosteroids
Pneumococcal infections if the patient must have a splenectomy
Prognosis
Children
o
Approximately 83% of children have a spontaneous remission, and 89% of
children eventually recover.
o
More than 50% of patients recover within 4-8 weeks.
o
Approximately 2% of patients die.
Adults
o
Only 2% of adults have a spontaneous recovery; however, approximately 64% of
adults eventually recover.
o
Approximately 30% of patients have chronic disease, and 5% of patients die from
hemorrhage.
Patient Education
Instruct patients to return for follow-up in order to assess for a potentially reduced
platelet count.
Emphasize close outpatient follow-up care.
Because of the increased risk of bleeding, instruct patients to avoid aspirin
products.
HEMORRHAGIC VASCULITIS (SCHÖNLEIN-HENOCH
DISEASE).
Most common vasculitis among children in United States;
leukocytoclastic vasculitis (vascular damage from nuclear debris of infiltrating
neutrophils) + IgA deposition in small vessels (arterioles and venules) of skin,
joints, GI tract and kidney.
Worldwide distribution, all ethnic groups; slightly greater in males; almost
all age 3-10 years; occurs mostly in fall, winter and spring, many after an URI
Infectious trigger is suspected, mediated by IgA and IgA-immune complexes
Genetic component suggested by occasional family clusters
Skin biopsy shows vasculitis of dermal capillaries and postcapillary venules
with infiltrates of neutrophils and monocytes; in all tissues, immunofluorescence
shows IgA deposition in walls of small vessels and smaller amounts of C3,
fibrin and IgM
Clinical presentation:
Nonspecific constitutional findings
Rash: palpable purpura, start as pink macules and then become petechial
and then purpuric or ecchymotic; usually symmetric and in gravity-dependent
areas (legs and back of arms) and pressure points (buttocks); lesions evolve in
crops over 3-10 days and may recur up to 4 months. Usually there is some
amount of subcutaneous edema
Arthralgia/arthritis: oligoarticular, self-limited and in lower extremities;
resolves
in
about
2
weeks, but may recur
GI: in up to 80%: pain, vomiting, diarrhea, ileus, melena, intussusception,
mesenteric ischemia or perforation (purpura in GI tract)
Renal: up to 50%: hematuria, proteinuria, hypertension, nephritis,
nephrosis, acute or chronic renal failure
Neurological: due to hypertension or CNS vasculitis, possible intracranial
hemorrhage, seizures, headaches and behavioral changes
Less common: orchitis, carditis, inflammatory eye disease, testicular torsion
and pulmonary
hemorrhage
American College of Rheumatology diagnosis: need 2 of the following:
palpable purpura age of onset <10 years
bowel angina = postprandial pain, bloody diarrhea
biopsy showing intramural granulocytes in small arterioles and
venules
Labs (none are diagnostic): increased WBCs, platelets, mild anemia,
increased ESR, CRP; stool + for occult blood; increased serum IgA. Must assess
and follow BP, UA, serum Cr; GI ultrasound: bowel wall edema, rarely
intussusception; skin and renal biopsies would be diagnostic but are rarely
performed (only for severe or questionable cases)
Treatment: supportive and corticosteroids (with significant GI
involvement or life-threatening complications only), although steroids will
not alter course/overall prognosis or prevent renal disease. For chronic renal
disease – azathioprine, cyclophosphamide, mycophenolate mofetil.
Outcome: Most significant acute complications affecting morbidity and
mortality
=
serious
GI
involvement; renal complications are major long-term and can develop up to 6
months after initial diagnosis, but rarely if initial UA and BP are normal.
Monitor all patients for 6months with BP and UA. Overall prognosis is
excellent; most have an acute, self-limited disease; about 30% have >1
recurrence, especially in 4-6 months, but with each relapse symptoms are less. If
more severe at presentation, higher risk for relapses. 1-2% with chronic renal
disease and 8% ESRD.
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