Pediatric emergency medicine trisk 2742 2742
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Infections may be accompanied by cutaneous manifestations (see Chapter 94
Infectious Disease Emergencies ). Although not unique to oncology patients, certain
infections affecting the skin may be more common in this patient group.
Immunosuppressed patients are at increased risk for herpes simplex and herpes
zoster. Any skin lesions in a dermatomal distribution, with or without associated
pain and whether or not the lesions are “classic,” should be considered herpes zoster
until proven otherwise. Immunocompromised patients with herpes zoster have an
increased risk of disseminated disease and should be placed in respiratory isolation.
Evaluation should include chest radiograph and liver function tests. If there is a
vesicular lesion, it should be scraped and sent for both rapid testing (e.g., PCR) and
culture for herpes simplex and varicella zoster. Empiric therapy should be started
with either acyclovir or one of its derivatives. Admission for intravenous therapy is
indicated in patients in whom there is evidence of dissemination, ophthalmologic
involvement, or failure to respond to oral therapy. Oral home therapy can be
considered in consultation with the oncologist after considering extent of
involvement, degree of underlying immunosuppression, likelihood of medication
compliance at home, and ability to follow up.
COMPLICATIONS OF HEMATOPOIETIC STEM CELL
TRANSPLANTATION
Bone marrow transplantation is increasingly utilized in the treatment of various
hematologic, oncologic, metabolic, or immunologic diseases. In hematologic
malignancies, allogeneic marrow transplantation may follow initial remission,
induction, or disease relapse. The allogeneic donor may be related, usually a sibling,
or unrelated to the recipient. In solid tumors and some lymphomas, patients may
receive aggressive chemotherapy and radiation and then have their own stem cells
infused as a “rescue” to help reconstitute their immune system following therapy
(autologous transplant). Knowledge of the type of transplant a patient received (
Table 98.11 ) can help the clinician anticipate what complications might ensue. In
general, stem cell transplant recipients represent a fragile patient population at risk
for many complications.
In approaching these patients, substantial immunosuppression should be
presumed for at least 6 months following the transplant. For patients still receiving
immunosuppressing medications, the period of immune dysfunction may be much
longer. Regardless of the WBC and neutrophil counts, immune function following a
stem cell transplant can be profoundly impaired.
Graft-versus-host disease (GVHD) may develop in the setting of allogeneic stem
cell transplants as newly engrafted immune cells of the donor react against tissue
antigens of the recipient that are perceived to be foreign ( Table 98.11 ). Acute
GVHD occurs in the first 100 days posttransplant, often when patient is still in
