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

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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) 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 coagulase- positive 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 spp., Agrobacterium spp., and Acinetobacter baumannii as well as Pseudomonas spp. other than aeruginosa are likely to be
very 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) that normally live in a commensal relationship with the host. The antimetabolic effects of chemotherapy cause a breakdown of host defenses, leading to ulceration of the mouth and the potential for invasion by resident bacteria. Mouth ulcerations afflict most patients receiving chemotherapy and have been associated with viridans streptococcal bacteremia. The use of keratinocyte growth factor (palifermin) in a daily dose of 60 µg/kg for 3 days before chemotherapy and total-body irradiation is 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 (such as voriconazole) are similarly effective. Noma (cancrum oris), commonly seen in malnourished children, is a penetrating disease of the soft and hard tissues of the mouth and adjacent sites,
with resulting necrosis and gangrene. It has a counterpart in immunocompromised patients and is thought to be due to invasion of the tissues by Bacteroides, Fusobacterium, and other normal inhabitants of the mouth. Noma is associated with debility, poor oral hygiene, and immunosuppression. Viruses, particularly HSV, are a prominent cause of morbidity in immunocompromised 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 substernal chest pain upon swallowing) includes herpes simplex and candidiasis, both of which are readily treatable. Lower Gastrointestinal Tract Disease Hepatic candidiasis (Chap. 196) results from seeding of the liver (usually from a gastrointestinal source) in neutropenic patients. It is most common in patients being treated for acute leukemia and usually presents symptomatically around the time the neutropenia resolves. The characteristic picture is that of
persistent fever unresponsive to antibiotics; abdominal pain and tenderness or nausea; and elevated serum levels of alkaline phosphatase in a patient with hematologic malignancy who has recently recovered from neutropenia. The diagnosis of this disease (which may present in an indolent manner and persist for several months) is based on the finding of yeasts or pseudohyphae in granulomatous lesions. Hepatic ultrasound or CT may reveal bull's-eye lesions. In some cases, MRI reveals small lesions not visible by other imaging modalities. The pathology (a granulomatous response) and the timing (with resolution of neutropenia and an elevation in granulocyte count) suggest that the host response to Candida is an important component of the manifestations of disease. In many cases, although organisms are visible, cultures of biopsied material may be negative. The designation hepatosplenic candidiasis or hepatic candidiasis is a misnomer because the disease often involves the kidneys and other tissues; the term chronic disseminated candidiasis may be more appropriate. Because of the risk of bleeding with liver biopsy, diagnosis is often based on imaging studies (MRI, CT). Amphotericin B is traditionally used for therapy (often for several months, until all manifestations of disease have disappeared), but fluconazole may be useful for outpatient therapy. The use of other antifungal agents and combination therapy is less well studied.