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other causes of neutropenia should be considered including the use of drugs associated
with neutropenia (see Table 93.7 ), as well as other underlying disorders. Genetic testing
for congenital neutropenias should be pursued in infants, usually at follow-up with a
pediatric hematologist. Consider underlying disorders such as malignancies or
nutritional disturbances (folate and vitamin B12 ). If the etiology is suspected to be viral
suppression and neutrophil count has resolved on repeat testing, no further evaluation
may be required. If no etiology is identified and neutropenia persists on repeat follow-up
testing, additional evaluation should be performed in consultation with a pediatric
hematologist. Workup for patients with unexplained neutropenia should include CBC
with differential and peripheral smear review, nutritional studies (such as folate and
vitamin B12 ), and may include antineutrophil antibodies, bone marrow aspiration and
biopsy (if neutropenia is persistent and without clear etiology), serum immunoglobulins,
and virology screen. Patients with some forms of chronic neutropenia may be treated
with granulocyte colony-stimulating factor (G-CSF), especially in the setting of
recurrent infections. Neonatal alloimmune neutropenia may be treated with IVIG and
eventually resolves as the maternal antibody titer wanes.
Clinical Indications for Discharge or Admission
The afebrile neutropenic patient who is well appearing and has no other significant
comorbidities may be evaluated on an outpatient basis in consultation with hematology.
For febrile but well-appearing neutropenic patients with good marrow function (e.g.,
noncancer or bone marrow failure patients), outpatient management is typically
reasonable after blood cultures are obtained and antibiotics administered. If severe
neutropenia is present (ANC <500/μL), consider consultation with hematology to
determine the need for admission.
Any ill-appearing child with fever and neutropenia or those who are well appearing in
the setting of underlying poor marrow function require admission for empiric IV
antibiotics and clinical monitoring. Admission should also be considered for any febrile
child with severe neutropenia (ANC <500/μL).

DISORDERS OF NEUTROPHIL FUNCTION
Numerous disorders of neutrophil function tend to have normal or elevated neutrophil

counts; however, these conditions can be associated with serious infections. Evaluate
and treat patients with abnormal neutrophil function based on the specific cause and the
history of serious infection. For example, chronic granulomatous disease (CGD) has
characteristic features including the site of infection (liver, bones, GI tract) and specific
causative organisms that require directed therapy (Aspergillus species, Pseudomonas
cepacia, Serratia marcescens ). Guidelines for the management of febrile illnesses are
generally similar to those for the management of patients with neutropenia.

PLATELET DISORDERS


Goals of Treatment
The management of platelet disorders is targeted at preventing and managing
hemorrhage, notably intracranial hemorrhage or bleeding causing hemodynamic
compromise. In most cases, bleeding rather than the platelet count dictates the need for
platelet transfusion or other therapy. Patients often manifest different degrees of
bleeding at a given platelet count, especially across different causative mechanisms.

IMMUNE THROMBOCYTOPENIA
CLINICAL PEARLS AND PITFALLS
Bleeding stigmata due to decreased platelet number are variable but mucosal
bleeding and petechiae are most typical.
Significant spontaneous bleeding is uncommon above platelet counts of
20,000/μL.
For thrombocytopenia with minimal or no bleeding symptoms, observation is
typically appropriate.
Parents and clinicians must be vigilant for signs or symptoms of intracranial
hemorrhage.

Current Evidence

Immune thrombocytopenia (ITP), formerly known as idiopathic thrombocytopenic
purpura, is the most commonly encountered cause of severely low platelets in otherwise
healthy children. This isolated thrombocytopenia arises due to immunologic destruction
without a known precipitant in the case of primary ITP, or in association with
autoimmune disorders, viral processes, or drugs in the case of secondary ITP. Serious
bleeding is rare (<2%). This low frequency is particularly remarkable because the
disease is most common in children between the ages of 1 and 4 years, who have the
expected developmental predilection toward minor trauma.
ITP may be newly diagnosed, persistent (3 to 12 months) or chronic (>12 months).
For the diagnosis and management of persistent or chronic ITP, hematology consultation
is advised. Anemia is uncommon but hemorrhagic manifestations can result in moderate
or severe anemia. Adolescents with ITP may develop significant anemia due to heavy
menstrual bleeding. Evans syndrome, which is defined as immune destruction of two or
more blood cell lines, can be an alternative explanation for anemia with ITP. The lifethreatening complication of ITP is intracranial hemorrhage. Consider intracranial
hemorrhage in any patient with ITP with symptoms of intracranial injury (change in
mental status, vomiting, neurologic abnormality) even in the absence of a clear history
of head trauma, as the precipitating event can be quite minor. The relationship between
platelet count and bleeding symptoms is not precise. Intracranial hemorrhage is


fortunately rare, but patients are at highest risk when platelet counts are <10,000/μL.
Other severe hemorrhage can occur from the nasal mucosa, gastrointestinal tract, or
other internal sites.

Clinical Considerations
Clinical Recognition
The classic presentation of the child with ITP is a well-appearing child with unexplained
ecchymoses and petechiae that may be accompanied by gingival bleeding, epistaxis, and
hematuria. Any child with unexplained bleeding warrants evaluation for
thrombocytopenia, followed by evaluation for its etiology. The peak incidence of

childhood ITP is children 2 to 6 years old. There may be a history of a recent
immunization or antecedent viral illness. In children less than 1 year of age, consider a
possible underlying immunodeficiency. In adolescent patients, there is a higher
prevalence of concurrent autoimmune disorders. ITP is a diagnosis of exclusion;
atypical features warrant evaluation for other etiologies.
Triage
A child with petechiae and fever, even if well appearing, should be assumed to have an
infectious process and to be at risk for sepsis until proven otherwise and managed
accordingly. Initial triage for afebrile patients includes evaluation for evidence of
hemodynamic instability related to associated hemorrhage and anemia, and neurologic
changes concerning for intracranial hemorrhage. A localized bruising pattern is atypical
for ITP and should prompt consideration of nonaccidental injury.
Initial Assessment/H&P
The history of the present illness in suspected ITP should focus on any history of
bleeding or bruising. Questions about nosebleeds or gingival bleeding with
teethbrushing can be helpful. Less commonly, patients will report blood in urine or
stool. Postmenarchal patients should be queried about menorrhagia. Evaluate any recent
medication use that could affect platelet function. Review of systems should include
evaluation for fever, fatigue, anorexia, weight loss, bone or joint pain, or other clues to
an underlying systemic process. Although often limited in pediatric patients, a history of
prior surgical procedures including circumcision, tonsillectomy and adenoidectomy, or
dental procedures (e.g., extractions), is important to assess response to hemostatic
challenges that may prompt suspicion of a congenital bleeding disorder. Family history
should include questions regarding hematologic and immunologic processes. The
physical examination should focus first on vital signs. In the hemodynamically stable
patient, perform a thorough physical examination, with particular attention to evidence
of mucosal bleeding (e.g., epistaxis, gingival bleeding, oropharyngeal hematomas,
positive stool guaiac), tachycardia (a clue to possible underlying anemia),
hepatosplenomegaly (may suggest a consumptive process), lymphadenopathy

(suggestive of an infectious or malignant process), and a dermatologic examination for
evidence of petechiae, purpura, or ecchymoses. Children with ITP generally have a
normal physical examination except for petechial rash, ecchymoses, and other signs of
bleeding.
Management/Diagnostic Testing
Initial Evaluation and Diagnosis. The diagnosis of ITP should be considered in all
patients with isolated thrombocytopenia with a platelet count less than 100,000/μL.
Initial lab tests include CBC, reticulocyte count, blood smear for review, and type and
screen. Direct antibody test (Coombs), coagulation panel, uric acid, and other tests
should be performed based on clinical presentation. Atypical features should prompt
consideration of other diagnoses and further evaluation.
The well-appearing child with a normal physical examination, isolated
thrombocytopenia, characteristic findings on peripheral blood smear, an unremarkable
personal and family history, and absence of history or examination findings suggestive
of an alternate diagnosis may be diagnosed with ITP. Although some controversy exists,
bone marrow biopsy and aspiration is generally unnecessary in children older than 12
months with a typical presentation. Any historical or physical examination features
raising concern for an oncologic process should prompt bone marrow evaluation before
the initiation treatment. If a patient with acute leukemia is mistakenly diagnosed as
having ITP and treated with steroids, the correct diagnosis of leukemia may be delayed
and long-term outcome could be adversely affected.
Treatment
Increasingly, the management of ITP is guided by bleeding symptoms rather than the
platelet count. Management of an acute episode for a patient with persistent or chronic
ITP should be based on past successful therapy and in conjunction with the primary
hematologist. There is practice heterogeneity for when and how to treat pediatric
patients with acute ITP. Here we provide an approach based on the recent American
Society of Hematology guidelines. Many patients with acute ITP with absent or mild
bleeding may be managed with observation. Indications for pharmacologic intervention

include moderate bleeding symptoms ( Table 93.8 ), inability to keep patients safe from
significant head trauma, or the need for surgery. Most, though not all, of these patients
will have platelet counts below 30,000/μL. For patients with moderate–severe bleeding
symptoms, several initial medications and dosing regimens are cited in the literature.
Table 93.9 presents a few examples of regimens used. IVIG and steroids are the two
most common first-line treatments. Anti-D is relatively contraindicated if hematocrit is
low due to bleeding or if there is evidence of autoimmune hemolysis, and now carries an
FDA black box warning due to risk of severe hemolysis. For life-threatening bleeding,
which is fortunately rare in this population, platelet transfusion and in some cases
emergent splenectomy are required in addition to initiating pharmacotherapy. Avoid