Focal encephalitis following varicella-zoster virus reactivation without rash in a healthy immunized young adult.

Herein we describe an episode of focal varicella-zoster virus (VZV) encephalitis in a healthy young man with neither rash nor radicular pain. The symptoms began with headaches and seizures, after which magnetic resonance imaging detected a single hyperintense lesion in the left temporal lobe. Because of the provisional diagnosis of a brain tumor, the lesion was excised and submitted for pathological examination. No tumor was found. But the tissue immunostained positively for VZV antigens, and wild-type VZV sequences were detected. In short, this case represents VZV reactivation, most likely in the trigeminal ganglion, in the absence of clinical herpes zoster.

Mycobacterium fortuitum prosthetic valve endocarditis: a case for the pathogenetic role of biofilms.

BACKGROUND: Prosthetic valve endocarditis presents unique challenges for both diagnosis and treatment. A potential role of biofilm has been hypothesized in the pathogenesis of these infections. METHODS: A patient with infective endocarditis involving a stentless (Freestyle) porcine prosthetic aortic valve with annular abscess and paravalvular leak 8 months after implantation is reported. RESULTS: The infected valve did not show vegetations or perforations, but histiocytic inflammation was seen along the endocardial surfaces of the valve. Auramine-rhodamine staining revealed many acid-fast organisms associated with the inflammation. There was also an acellular matrix material with ultrastructural features of biofilm. Blood cultures grew Mycobacterium fortuitum, a biofilm-associated microbe. CONCLUSIONS: The role of biofilm in prosthetic valve endocarditis is discussed. The importance of microscopy for prosthetic valves, even when no vegetations are present, is highlighted along with correlation of pathologic findings with culture results.

General principles of antimicrobial therapy.

Antimicrobial agents are some of the most widely, and often injudiciously, used therapeutic drugs worldwide. Important considerations when prescribing antimicrobial therapy include obtaining an accurate diagnosis of infection; understanding the difference between empiric and definitive therapy; identifying opportunities to switch to narrow-spectrum, cost-effective oral agents for the shortest duration necessary; understanding drug characteristics that are peculiar to antimicrobial agents (such as pharmacodynamics and efficacy at the site of infection); accounting for host characteristics that influence antimicrobial activity; and in turn, recognizing the adverse effects of antimicrobial agents on the host. It is also important to understand the importance of antimicrobial stewardship, to know when to consult infectious disease specialists for guidance, and to be able to identify situations when antimicrobial therapy is not needed. By following these general principles, all practicing physicians should be able to use antimicrobial agents in a responsible manner that benefits both the individual patient and the community.

Mycobacterium intermedium granulomatous dermatitis from hot tub exposure.

Nontuberculous mycobacteria, which are widespread in the environment, frequently cause opportunistic infections in immunocompromised patients. We report the first case of a patient with chronic granulomatous dermatitis caused by a rarely described organism, Mycobacterium intermedium. The infection was associated with exposure in a home hot tub.

Vestibular toxicity due to inhaled tobramycin in a patient with renal insufficiency.

Inhaled tobramycin is being used increasingly in patients with cystic fibrosis and other forms of bronchiectasis for treatment of bronchial colonization with Pseudomonas aeruginosa. The goal of inhaled antibiotics is to provide maximal concentrations at the site of infection without risking systemic toxicity. We report an unusual case of reversible vestibular toxicity due to inhaled tobramycin in a patient with renal failure who was undergoing hemodialysis. Although systemic absorption after inhaled tobramycin is reportedly negligible, no recommendations have been published regarding monitoring of serum concentrations in patients receiving this form of therapy. We suggest that clinicians consider monitoring serum concentrations of tobramycin in patients at risk of renal toxicity and/or ototoxicity, such as those with predisposing renal or otologic compromise. Further studies in at-risk patients are needed to determine the optimal frequency and timing of such monitoring.

Pulmonary cryptococcosis in nonimmunocompromised patients.

BACKGROUND: Cryptococcus neoformans can cause serious systemic infections requiring systemic antifungal therapy in immunocompromised hosts. However, isolated pulmonary cryptococcosis in nonimmunocompromised hosts has been reported to resolve spontaneously without treatment. STUDY OBJECTIVE: s: To determine the role of antifungal therapy in the management of isolated pulmonary cryptococcosis in nonimmunocompromised hosts. DESIGN: Retrospective study. SETTING: Tertiary care, referral medical center PATIENTS: Thirty-six nonimmunocompromised subjects with isolated pulmonary cryptococcosis who received diagnoses at the Mayo Clinic (Rochester, MN) from 1976 to 2001. INTERVENTIONS: None. MEASUREMENTS AND RESULTS: Of 42 nonimmunocompromised subjects with cryptococcal infections, 36 (86%) had isolated pulmonary cryptococcosis. The mean (+/- SD) age of these 36 patients was 61 +/- 15 years (range, 14 to 88 years), and the groups included 17 men (47%) and 19 women (53%). Twenty-four patients (67%) were symptomatic, and 12 patients (33%) were asymptomatic. The most common presenting symptoms were cough, dyspnea, and fever. Cultures of sputum and bronchial washings most commonly yielded the diagnosis. Cerebrospinal fluid examination was performed in 11 patients (31%) and was negative in all of them. Follow-up information was available on 25 patients (69%) with a median duration of 19 months (range, 1 to 330 months). Twenty-three of these patients (92%) had resolution of their disease (no treatment, 8 patients; surgical resection only, 6 patients; and antifungal therapy, 9 patients). The condition of the two remaining patients had improved. There was no documented treatment failure, relapse, dissemination, or death in any of these 25 patients. CONCLUSIONS: Our findings suggest that an initial period of observation without the administration of antifungal therapy is a reasonable option for nonimmunocompromised subjects with pulmonary cryptococcosis in the absence of systemic symptoms or evidence of dissemination, as well as after surgical resection for focal cryptococcal pneumonia.

Fever of unknown origin caused by multiple myeloma: a report of 9 cases.

BACKGROUND: Most authorities regard multiple myeloma as a rare cause of fever and not a cause of fever of unknown origin (FUO). OBJECTIVE: To describe a series of patients with FUO caused by multiple myeloma. METHODS: We reviewed the clinical features of 9 patients seen at Mayo Clinic from January 1, 1975, to February 1, 2001, with FUO caused by multiple myeloma. RESULTS: Fever of unknown origin caused by multiple myeloma was found in 9 patients (6 men and 3 women). All patients satisfied accepted criteria for FUO. The mean +/- SD time from the onset of fevers to the initial physician evaluation was 4.8 +/- 2.0 weeks. The mean time from the initial physician evaluation to the diagnosis of multiple myeloma was 11.4 +/- 6.5 weeks. The mean age at diagnosis of multiple myeloma was 55.9 +/- 6.9 years. All 9 patients were anemic. Peripheral blood smears were available for 8 patients, and all had rouleaux formations. All 9 patients underwent exhaustive testing to determine the cause of fevers. Further testing was done in 6 patients subsequent to the diagnosis of multiple myeloma. Acetaminophen or nonsteroidal anti-inflammatory drugs or both relieved fevers in all patients who received them. All 8 patients who received chemotherapy experienced resolution of fevers. The median actuarial survival of the patient cohort was 38 months. CONCLUSIONS: Multiple myeloma can cause FUO. When appropriate, clinicians should include multiple myeloma in the differential diagnosis of FUO to reduce unnecessary testing, rapidly establish the diagnosis, and initiate effective treatments.

Mycobacterium bovis vertebral osteomyelitis as a complication of intravesical BCG use.

We report a culture-proven case of Mycobacterium bovis vertebral osteomyelitis in a 76-year-old man who had undergone intravesical BCG therapy for bladder cancer 7 years previously. He presented with debilitating back pain and had radiographic evidence of T6-7 disk space destruction with involvement of adjacent vertebrae. Tissue culture from the disk space confirmed the diagnosis of vertebral osteomyelitis due to hematogenous spread of M. bovis. Treatment with antituberculous medications was begun soon after tissue diagnosis was made, and the patient fared well with medical therapy alone. Although uncommon, this infectious complication of BCG therapy should always be considered in the appropriate clinical setting. Timely diagnosis is important, because chemotherapy, when initiated early in the disease, can preclude the necessity for surgical intervention.