Pediatric emergency medicine trisk 556
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appropriate cultures from identified sources of infection (e.g., skin abscess, cellulitis).
Examine cerebrospinal fluid when CNS infection is suspected. Appropriate antibiotics
should be promptly administered to all febrile neutropenic patients while awaiting
culture results.
Clinical Recognition
There are a wide range of causes of neutropenia in children. Etiologies of neutropenia
can be divided into congenital or acquired. Congenital forms of neutropenia such as
severe congenital neutropenia and cyclic neutropenia arise from specific genetic
mutations. Several syndromes including myelokathexis/WHIM syndrome, Shwachman–
Diamond syndrome, and Chédiak–Higashi syndrome are also associated with
neutropenia. Acquired forms arise from infections, drugs, or autoimmunity ( Table 93.7
) and are especially common in patients undergoing chemotherapy for oncologic
processes. Immune-mediated conditions are caused by neutrophil-specific antibodies.
These include neonatal alloimmune neutropenia, a severe but self-limited neutropenia
secondary to transplacental maternal antibodies, and primary autoimmune neutropenia.
Idiopathic neutropenia occurs without evidence of congenital, immune, or cyclic
neutropenia.
Triage
The most important triage consideration is to identify febrile neutropenic patients, and
among those to recognize ill-appearing children who require aggressive management.
Early administration of broad-spectrum IV antibiotics should be a primary focus.
TABLE 93.7
CAUSES OF NEUTROPENIA AND DISORDERS OF NEUTROPHIL
FUNCTION IN CHILDREN
Inherited neutropenia
Severe congenital neutropenia—includes autosomal dominant (neutrophil elastase
mutation), autosomal recessive Kostmann disease
Cyclic neutropenia
Dyskeratosis congenita
Shwachman–Diamond syndrome
Congenital neutropenia associated with pigmentation and or immune disorders—
Chédiak–Higashi syndrome, Griscelli syndrome, Hermansky–Pudlak syndrome
Reticular dysgenesis, myelokathexis/WHIM syndrome
Other neutropenias—metaphyseal chondrodysplasia or cartilage–hair hypoplasia,
Barth syndrome, glycogen storage type 1b, Gaucher disease, Niemann–Pick disease
Acquired neutropenias
Drugs and chemical toxins
Anticonvulsant: carbamazepine, valproate
Antimicrobial: sulfonamides, penicillins, trimethoprim/sulfamethoxazole, quinine
Antipsychotic: clozapine, olanzapine, phenothiazines
Antirheumatic: gold, levamisole, penicillamine
Antithyroid: methimazole, propylthiouracil
Other: aminopyrine, deferiprone, rituximab, levamisole-adulterated cocaine,
phenothiazines, thiouracil
Dose-dependent myeloid suppression, cytotoxic drugs, antimetabolites
Iatrogenic causes (radiotherapy, radioactive treatments)
Infection (bacterial, viral, rickettsial, protozoal)—usually transient
Bacterial: Brucella , paratyphoid, tuberculosis, tularemia, typhoid
Viral: CMV, EBV, HIV, influenza, parvovirus B19, hepatitides A, B; RSV, rubella,
measles, varicella
Rickettsial: Anaplasma phagocytophilum, other rickettsia
Protozoan: Plasmodium vivax, Plasmodium falciparum
Bone marrow infiltration or failure (leukemia, aplastic anemia,
hypogammaglobulinemia, hemophagocytic lymphohistiocytosis)
Nutritional deficiencies (starvation; anorexia nervosa; vitamin B12 , folate, zinc, and
copper deficiencies)
Immune neutropenias (collagen vascular diseases, Felty syndrome, neonatal
isoimmune neutropenia, autoimmune neutropenia including chronic benign
neutropenia of childhood)
Disorders of neutrophil function
Abnormal adhesion (leukocyte adhesion deficiency)
Abnormal chemotaxis (hyperimmunoglobulin E syndrome)
Abnormal opsonization and ingestion (complement deficiency, leukocyte adhesion
deficiency)
Abnormal degranulation (Chédiak–Higashi syndrome)
Abnormal oxidative metabolism (chronic granulomatous disease, myeloperoxidase
deficiency)
Acquired disorders of phagocytic dysfunction (malnutrition, malignancies, severe
burns)
Initial Assessment/H&P
Attention to frequency, site, and severity of prior infections is critical. Ascertain the
height of fever, other constitutional symptoms, the presence of oral inflammation, and
history of other infections. Family history may help diagnose cyclic neutropenia.
Detailing exposure to medications and toxins including herbal or “natural” remedies
may reveal a cause of acquired disease. Congenital neutropenia usually presents in
infancy with severe or recurrent bacterial or fungal infections typically of the skin,
mucosa, or lungs. Explore the family history for recurrent infections or deaths in early
childhood that might suggest a congenital neutropenia.
On physical examination, evidence of mouth ulcers as well as gingival, periodontal,
or dental issues may indicate neutropenia. Acute abdominal pain and fever should raise
concerns about neutropenic colitis (also known as typhlitis) and sepsis. Examine the
perirectal and anal areas for cellulitis. In the absence of neutrophils, the degree of
induration may lead clinicians to underestimate the severity of infection.
Management/Diagnostic Testing
Management of neutropenic patients depends on the degree and etiology of the
neutropenia (see Table 93.7 ). Neutropenic oncology patients are a special category (see
Chapter 98 Oncologic Emergencies ). Febrile neutropenic patients require CBC and
blood cultures. For ill-appearing febrile patients and febrile neutropenic patients with
poor marrow function (congenital neutropenias and bone marrow failure syndromes),
treat with broad-spectrum IV antibiotic therapy that includes antibiotics effective against
skin and gastrointestinal flora, and anaerobic coverage if abdominal pain is present. An
example initial regimen may include ceftriaxone, vancomycin, and metronidazole. For
persistent fever (>4 days), empiric antifungal coverage should be considered. Febrile
neutropenic patients with normal marrow function (autoimmune-mediated neutropenias)
who are well appearing with reassuring vital signs and no history of severe infection are
often managed as outpatients following a dose of ceftriaxone; fluoroquinolones are the
most common alternative in allergic patients.
Neutropenia is occasionally discovered during an evaluation for fever. In most of
these instances, both the fever and neutropenia result from a viral illness. Serious
secondary bacterial infections are unlikely with mild to moderate neutropenia; however,
because the neutropenia usually cannot be attributed with certainty to a viral illness,
