Chapter 082. Infections in Patients with Cancer (Part 6)

More common than tunnel infections are exit-site infections, often with erythema around the area where the line penetrates the skin. Most authorities (Chap. 129) recommend treatment (usually with vancomycin) for an exit-site infection caused by a coagulase-negative Staphylococcus. Treatment of coagulasepositive staphylococcal infection is associated with a poorer outcome, and it is advisable to remove the catheter if possible. Similarly, many clinicians remove catheters associated with infections due to P. aeruginosa and Candida species, since such infections are difficult to treat and bloodstream infections with these organisms are likely to be deadly. Catheter infections caused by Burkholderia cepacia, Stenotrophomonas...
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Chapter 082. Infections in Patients with Cancer (Part 6) Chapter 082. Infections in Patients with Cancer (Part 6) More common than tunnel infections are exit-site infections, often witherythema around the area where the line penetrates the skin. Most authorities(Chap. 129) recommend treatment (usually with vancomycin) for an exit-siteinfection caused by a coagulase-negative Staphylococcus. Treatment of coagulase-positive staphylococcal infection is associated with a poorer outcome, and it isadvisable to remove the catheter if possible. Similarly, many clinicians removecatheters associated with infections due to P. aeruginosa and Candida species,since such infections are difficult to treat and bloodstream infections with theseorganisms are likely to be deadly. Catheter infections caused by Burkholderiacepacia, Stenotrophomonas spp., Agrobacterium spp., and Acinetobacterbaumannii as well as Pseudomonas spp. other than aeruginosa are likely to bevery difficult to eradicate with antibiotics alone. Similarly, isolation of Bacillus,Corynebacterium, and Mycobacterium spp. should prompt removal of the catheter. Gastrointestinal Tract–Specific Syndromes Upper Gastrointestinal Tract Disease Infections of the Mouth The oral cavity is rich in aerobic and anaerobic bacteria (Chap. 157) thatnormally live in a commensal relationship with the host. The antimetabolic effectsof chemotherapy cause a breakdown of host defenses, leading to ulceration of themouth and the potential for invasion by resident bacteria. Mouth ulcerations afflictmost patients receiving chemotherapy and have been associated with viridansstreptococcal bacteremia. The use of keratinocyte growth factor (palifermin) in adaily dose of 60 µg/kg for 3 days before chemotherapy and total-body irradiationis of proven value in preventing mucosal ulceration after stem cell transplantation.Fluconazole is clearly effective in the treatment of both local infections (thrush)and systemic infections (esophagitis) due to Candida albicans. Newer azoles (suchas voriconazole) are similarly effective. Noma (cancrum oris), commonly seen in malnourished children, is apenetrating disease of the soft and hard tissues of the mouth and adjacent sites,with resulting necrosis and gangrene. It has a counterpart in immunocompromisedpatients and is thought to be due to invasion of the tissues by Bacteroides,Fusobacterium, and other normal inhabitants of the mouth. Noma is associatedwith debility, poor oral hygiene, and immunosuppression. Viruses, particularly HSV, are a prominent cause of morbidity inimmunocompromised patients, in whom they are associated with severe mucositis.The use of acyclovir, either prophylactically or therapeutically, is of value. Esophageal Infections The differential diagnosis of esophagitis (usually presenting as substernalchest pain upon swallowing) includes herpes simplex and candidiasis, both ofwhich are readily treatable. Lower Gastrointestinal Tract Disease Hepatic candidiasis (Chap. 196) results from seeding of the liver (usuallyfrom a gastrointestinal source) in neutropenic patients. It is most common inpatients being treated for acute leukemia and usually presents symptomaticallyaround the time the neutropenia resolves. The characteristic picture is that ofpersistent fever unresponsive to antibiotics; abdominal pain and tenderness ornausea; and elevated serum levels of alkaline phosphatase in a patient withhematologic malignancy who has recently recovered from neutropenia. Thediagnosis of this disease (which may present in an indolent manner and persist forseveral months) is based on the finding of yeasts or pseudohyphae ingranulomatous lesions. Hepatic ultrasound or CT may reveal bulls-eye lesions. In some cases, MRIreveals small lesions not visible by other imaging modalities. The pathology (agranulomatous response) and the timing (with resolution of neutropenia and anelevation in granulocyte count) suggest that the host response to Candida is animportant component of the manifestations of disease. In many cases, althoughorganisms are visible, cultures of biopsied material may be negative. The designation hepatosplenic candidiasis or hepatic candidiasis is amisnomer because the disease often involves the kidneys and other tissues; theterm chronic disseminated candidiasis may be more appropriate. Because of therisk of bleeding with liver biopsy, diagnosis is often based on imaging studies(MRI, CT). Amphotericin B is traditionally used for therapy (often for severalmonths, until all manifestations of disease have disappeared), but fluconazole maybe useful for outpatient therapy. The use of other antifungal agents andcombination therapy is less well studied.