case report Rhinocerebral mucormycosis: A rare fungal infection linked to diabetes Although usually prevented by the immune system, this disease is common in patients who are immunocompromised. As in this case, early detection and treatment are key. Sarah Asman, MPA, PA-C; Mehrdad M. Behnia, MD, FACP, FCCP CASE A 37-year-old male presented to his primary care physician with acute onset periorbital edema, tinnitus, and nasal congestion. He attributed his symptoms to ongoing chronic sinusitis. On physical examination, the patient was afebrile and had ptosis of the right eyelid with periorbital edema and erythema. Edema and hypertrophy of the nasal turbinates and posterior pharynx were also present. His history included hypertension and chronic anxiety. The patient denied smoking but admitted to drinking alcohol socially. His physician made the primary diagnosis of periorbital cellulitis and admitted him to the hospital for treatment, where he was started on clindamycin, vancomycin, and piperacillin-tazobactam. Two days after admission, the patient exhibited altered mental status. On neurologic examination, he had facial asymmetry due to complete ptosis and significant edema of the right eyelid. Extraocular movements were intact but limited during upward gaze in the right eye. CT of the brain showed cavernous sinus thrombosis with similar changes to the orbit, a semiacute right frontal lobe infarct, and diffuse sinusitis (Figure 1). Heparin was started in conjunction with ceftriaxone for the cavernous sinus thrombosis, and the patient’s previous antibiotic regimen was discontinued. Based on an elevated hemoglobin A1C level of 7.8% and random blood glucose level of 260 mg/dL, a presumptive diagnosis of type 2 diabetes mellitus was made. On hospital day 3, the patient’s neurologic condition began to deteriorate acutely. He exhibited some posturing with blindness of the right eye; the right pupil became dilated and nonreactive. CT of the head showed hemorrhage in the area where the right frontal lobe infarct had been (Figure 2). Left pupillary response was intact. Heparin was stopped, and the patient was intubated because of concern that the airway was compromised. The following day, repeat CT of the head showed a large frontal bleed with surrounding edema and mass effect as well as subarachnoid hemorrhage (Figure 3). A B FIGURE 1. CT showing cavernous sinus thrombosis (a) and orbit thrombosis (b), with the red arrow indicating the pathologic area www.jaapa.com • december 2011 • 24(12) • JAAPA E1 case report | Rhinocerebral mucormycosis The patient underwent a frontal lobectomy with removal of the blood clot. A complete right ethmoidectomy, right maxillary sinus antrostomy, frontal sinusotomy, and sphenoidectomy were also performed. Intraoperatively, significant devitalized mucous membranes were seen within the nasal cavity that were suspicious for an acute fungal process. The area was debrided, and pathology was consistent with mucormycosis. The patient was started on IV amphotericin B and anidulafungin. Multiple debridements of the right nasal cavity were subsequently performed. Bilateral myringotomy with insertion of a tympanostomy was also performed, and he was started on hyperbaric oxygen therapy (HBO). His condition started to improve dramatically, and he was subsequently discharged to an outpatient rehabilitation program on posaconazole after 21 days of treatment with amphotericin B, anidulafungin, and ceftriaxone. FIGURE 2. Left, CT demonstrating right frontal lobe hemorrhage (red arrow) FIGURE 3. Right, CT showing frontal hemorrhage (red arrow) and surrounding edema and mass effect (yellow arrow) DISCUSSION Rhinocerebral mucormycosis is a rare fungal infection that historically is seen in the immunocompromised. Previously referred to as zygomycosis, changes in high-level taxonomy in reference to molecular phylogenetic analyses led to the class Zygomycota being renamed as Glomeromycota.1 Although this fungus is ubiquitous in the environment, the disease is usually prevented by the immune system and is therefore rare. As with other types of fungi, the most desirable environment for rhinocerebral mucormycosis to grow is in wet, damp places such as soil, composting vegetation, and bread. Well-recognized risk factors for the disease include diabetes mellitus, leukemia, aplastic anemia, myelodysplastic syndrome, blood dyscracias, immunosuppressive therapy in organ transplantation, renal disease, sepsis, and severe burns.2 The disease is primarily found in those who are immunocompromised, but it may also manifest in immunocompetent persons.3 In fact, in one study, nearly 20% of mucormycosis cases occurred in patients with “no underlying medical condition,” although the latter group had a history of penetrating trauma, surgery, or burns.3 Disease progression Rhinocerebral mucormycosis generally progresses in three stages.2 The first stage occurs after the fungal spores have been inhaled and infect the paranasal sinuses, resulting in formation of necrotic lesions in the nasal mucosa, turbinates, or hard palate.2 The second stage is characterized by direct extension of the disease into the maxillary sinus or invasion of the surrounding vasculature. During the last stage, the fungus spreads into the cribriform plate or the orbital apex.2 Rhinocerebral mucormycosis usually manifests as an acute sinus infection but can lead to serious complications such as cavernous sinus thrombosis and vascular invasion if not treated early.4,5 Table 1 lists the distinguishing features of both bacterial sinusitis and rhinocerebral mucormycosis. Delayed treatment may also cause the disease to spread rapidly to adjacent structures such as the brain and orbits or to occlude the carotid artery, causing an internal carotid artery pseudoaneurysm.2,4,5 If the fungus invades the blood vessels extensively, infarction and necrosis of the involved tissue will eventually result.2 Treatment As of now, treatment options for rhinocerebral mucormycosis are still being optimized. Current therapy for the invasive disease includes treating the underlying predisposing factors, antifungal therapy, and surgical debridement of the affected tissues. Early recognition of the disease and treating the underlying cause of mucormycosis, such as diabetes, are key to improving outcomes. The antifungal treatment of choice for mucormycosis is amphotericin B, although very high doses are required because of the relative resistance of the fungus to the drug. TEACHING POINTS ■■ Rhinocerebral mucormycosis is a rare fungal infection that historically is seen in the immunocompromised. ■■ Well-recognized risk factors for the disease include diabetes mellitus, leukemia, aplastic anemia, myelodysplastic syndrome, blood dyscracias, immunosuppressive therapy in organ transplantation, renal disease, sepsis, and severe burns. ■■ The infection progresses in three stages and usually manifests as an acute sinus infection. If not treated early, it can lead to serious complications such as cavernous sinus thrombosis and vascular invasion. ■■ Current therapy for the invasive disease includes treating the underlying predisposing factors, antifungal therapy, and surgical debridement of the affected tissues. ■■ Early recognition of the disease and treating the underlying cause of mucormycosis are key to improving outcomes. www.jaapa.com • december 2011 • 24(12) • JAAPA E2 case report | Rhinocerebral mucormycosis TABLE 1. Features of bacterial sinusitis and rhinocerebral mucormycosis10 Sinusitis Rhinocerebral mucormycosis Presentation • Unilateral facial pain • Severe facial pain over maxillary dentition • Clear- to strawor maxillary sinuses, colored nasal between eyes (ethmoid drainage sinuses), over forehead • Visual symptoms (frontal sinuses) or head may be noted vertex (sphenoid sinuses) at presentation • Acute onset (1-4 weeks), in absence of purulent green or yelsignificant nasal low nasal discharge or findings expectoration • Associated symptoms including cough, malaise, nasal congestion, fever, and headache Examination • Tenderness to palpation of the affected sinuses • Red, swollen nasal turbinates • Pathognomic finding: black eschar on the middle turbinate • Nasal mucosa can also appear normal or slightly pale Treatment • Two-thirds of untreated patients with acute bacterial rhinosinusitis will improve symptomatically within 2 weeks • Consider antibiotics when symptoms last longer than 10-14 d or when symptoms are severe • First-line therapy is amoxicillin, trimethoprim-sulfamethoxazole, or doxycycline • Prompt wide surgical debridement and amphotericin B by IV infusion or lipid-based amphotericin B in patients with renal insufficiency • Some evidence to suggest iron chelator therapy as adjunct treatment Amphotericin B works by binding to ergosterol, increasing the permeability of the fungal cell mebranes.6 Amphotericin B can be nephrotoxic, and renal indices should be monitored during therapy. Several studies have indicated that lipid formulations of amphotericin B, such as liposomal amphotericin B, may result in improved response rate and survival, reduction of fungal burden, and lesser nephrotoxicity.1 Surgical debridement is fundamental in combination with antifungal therapy because patients treated with antifungal therapy alone have very low cure rates.5 HBO has been reported by some to improve treatment outcomes in patients with rhinocerebral mucormycosis. Although no definitive evidence exists that this treatment can lower mortality, it has been used to ameliorate tissue hypoxia and lactic acidosis associated with mucormycosis.2 In one case study, three presumptive benefits of HBO were as follows: a) increased oxygenation to the vessels and tissues distal to the affected sites with resulting improvement in acidosis; b) inhibited growth of the fungus caused by the decrease in acidosis; and c) fungicidal properties of oxygen when provided in high quantities.7 Outcome In our patient, treatment was initiated with amphotericin B, anidulafungin (Eraxis), and ceftriaxone. Anidulafungin is an echinocandin antifungal that inhibits fungal cell wall synthesis by inhibiting beta 1,3 glucan.8 We thought that the combination of antifungals would be most beneficial to this patient based on the extent of the disease while the ceftriaxone would provide simultaneous broad spectrum coverage for other opportunistic bacteria. In addition, the additive effects of the two antifungals from different classes could potentiate a greater response to both drugs while attenuating the need for higher doses of amphotericin B required for extensive disease involvement. Posaconazole is a triazole oral antifungal with a good safety profile that blocks the synthesis of ergosterol. It can be used as salvage therapy or in conjunction with amphotericin B or echinocandin in the treatment of mucormycosis, although randomized trials are not available to prove its complete efficacy.9 Deferasirox, an oral iron chelator used for treatment of iron overload, has in vitro fungicidal activity against Mucorales. A phase II study, “DefrasiroxAmbisome Therapy for Mucormycosis,” has been completed, but results are yet to be published (NCT00419770). CONCLUSIONS This report summarizes the case of a patient with mucormycosis of the sinuses requiring extensive sinus debridement and cavernous sinus thrombosis. The hospital course was complicated by a large, frontal intracranial bleed with mass effect requiring craniotomy. He was treated with 21 days of IV amphotericin B, anidulafungin, and ceftriaxone in conjunction with HBO and outpatient posaconazole. Although mucormycosis is rare, clinicians must hold a high index of suspicion when dealing with patients who present with symptoms like those in our patient. Although complaints such as nasal congestion and periorbital edema are common in the primary care setting, the health care provider must take into account the patient’s underlying comorbidities when formulating a differential diagnosis. In this case report, undiagnosed diabetes mellitus was the precursor to the development of mucormycosis. Recognition and correction of the factors that predispose patients to rhinocerebral mucormycosis are critical in order to avoid serious complications of this rare infection. JaApa At the time this article was written, Sarah Asman was a PA student at Georgia Health Sciences University, Augusta, Georgia. She currently practices at Southern Surgical Group, West Columbia, South Carolina. Mehrdad Behnia is clinical associate professor of medicine at Georgia Health Sciences University. The authors have indicated no relationships to disclose relating to the content of this article. www.jaapa.com • december 2011 • 24(12) • JAAPA E3 case report | Rhinocerebral mucormycosis REFERENCES 1. Sun HY, Singh N. Mucormycosis: its contemporary face and management strategies. Lancet Infect Dis. 2011;11(4):301-311. 2. Alvernia JE, Patel RN, Cai DZ, et al. A successful combined endovascular and surgical treatment of a cranial base mucormycosis with an associated internal carotid artery pseudoaneurysm. Neurosurgery. 2009;65(4):733-740; discussion 740. 3. Cano P, Horseman MA, Surani S. Rhinocerebral mucormycosis complicated by bacterial brain abscess. Am J Med Sci. 2010;340(6):507-510. 4. Ibrahim AS, Spellberg B, Edwards J Jr. Iron acquisition: a novel perspective on mucormycosis pathogenesis and treatment. Curr Opin Infect Dis. 2008;21(6):620-625. 5. Ibrahim M, Chitnis S, Fallon K, Roberts T. Rhinocerebral mucormycosis in a 12-year-old girl. Arch Neurol. 2009;66(2):272-273. 6. Moen MD, Lyseng-Williamson KA, Scott LJ. Liposomal amphotericin B: a review of its use as empirical therapy in febrile neutropenia and in the treatment of invasive fungal infections. Drugs. 2009;69(3):361-392. 7. Price JC, Stevens DL. Hyperbaric oxygen in the treatment of rhinocerebral mucormycosis. Laryngoscope. 1980;90(5 pt 1):737-747. 8 Chen SC, Slavin MA, Sorrell TC. Echinocandin antifungal drugs in fungal infections: a comparison. Drugs. 2011;71(1):11-41. 9. Spellberg B, Walsh TJ, Kontoyiannis DP, et al. Recent advances in the management of mucormycosis: from bench to bedside. Clin Infect Dis. 2009;48(12):1743-1751. 10 McPhee S, Papadakis M, Rabow M, eds. Lange Current Medical Diagnosis and Treatment. 48th ed. New York, NY: McGraw Hill; 2009. www.jaapa.com • december 2011 • 24(12) • JAAPA E4
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