4.1 Rhinologic Emergencies
4.1.1 Acute Invasive Fungal Rhinosinusitis
Key Features
A rapidly progressive sinonasal fungal infection can be fatal.
Acute invasive fungal infections occur almost exclusively in immunocompromised or debilitated patients.
Successful treatment requires early detection, wide surgical débridement, and correction of the underlying predisposing condition.
In the debilitated patient, certain fungal infections can become angioinvasive with tissue necrosis, cranial nerve involvement, and possible orbital or intracranial extension. The most common organisms are Mucor or Aspergillus species. High-risk patients include those with neutropenia from any cause (e.g., leukemia, bone marrow transplantation), other oncology patients undergoing chemotherapy, patients undergoing chronic immunosuppressive therapy or corticosteroid use, patients with diabetes mellitus and diabetic ketoacidosis, and patients with acquired immunodeficiency syndrome (AIDS). Acute invasive fungal rhinosinusitis is a distinct and rapidly aggressive disease process that is distinguished by its fulminant course from other forms of fungal sinusitis, such as mycetoma, allergic fungal rhinosinusitis, or chronic invasive (indolent) fungal rhinosinusitis.
Epidemiology
Also known as rhinocerebral mucormycosis, acute invasive fungal rhinosinusitis occurs in the at-risk populations just described: patients with hematologic malignancies, patients post solid organ or bone marrow transplant, patients with diabetes, patients on chronic steroid therapy, neutropenic patients, and patients with AIDS.
Clinical
Signs and Symptoms
A high index of suspicion in any at-risk patient is required, as early diagnosis improves prognosis. A fever of unknown origin should raise suspicion, as should any new sign or symptom of sinonasal disease. Facial edema, periorbital swelling, pain, or numbness are common findings. However, the leukopenic patient may be unable to mount a febrile response. Other findings may include epistaxis, headache, mental status change, or crusting/eschar at the naris that can be mistaken for dried blood. One should consider unilateral cranial neuropathy, acute visual change, or altered ocular motility in an immunocompromised patient to be acute invasive fungal rhinosinusitis until proven otherwise. A black intranasal eschar on exam is considered pathognomonic for invasive Mucor.
Differential Diagnosis
A noninvasive sinonasal infection, such as acute bacterial sinusitis, should be considered. An acute bacterial sinusitis complication, such as orbital cellulitis or intracranial suppurative spread, may present similarly. Radiographically similar processes may include squamous cell carcinoma, sinonasal lymphoma, and Wegener′s granulomatosis.
Evaluation
See Fig. 4.4 for a diagnostic and treatment algorithm.
Physical Exam
The patient suspected to have acute invasive fungal rhinosinusitis should be seen without delay. The head and neck examination should focus on cranial nerve function and should include nasal endoscopy. Avoid tetracaine spray or other topical anesthetics. Insensate mucosa noted during an endoscopic exam is consistent with invasive fungal infection. Dark ulcers or pale, insensate mucosa may appear on the septum, conchae, palate, or nasopharynx. Early infection may appear as pale mucosa; the presence of dark eschar has been considered to be pathognomonic. Signs of cavernous sinus thrombosis include ophthalmoplegia, exophthalmos, and decreased papillary responses. Biopsy of suspicious areas such as the middle concha or septal mucosa is required for diagnosis. It is important to obtain actual tissue at biopsy, not just overlying eschar or necrotic debris. These specimens should be sent fresh for immediate frozen-section analysis as well as silver stain. Patients may be thrombocytopenic, and although a low platelet count may lead to profuse bleeding after biopsy, the risk of this must be balanced with the high mortality associated with a delay in diagnosis. If necessary, platelet transfusion should be ordered early. As a rule, a platelet count of 50,000 is desired. Acceptable hemostasis can usually be obtained with chemical cautery and Avitene (Davol, Inc., Cranston, RI), Gelfoam (Pfizer Pharmaceuticals, New York, NY), or other hemostatic packing.
Imaging
Computed tomography (CT) findings may be nonspecific. However, the presence of bone erosion and adjacent soft tissue edema on contrast-enhanced maxillofacial CT strongly suggests the diagnosis if clinical correlation is present. Unilateral edema of the nasal mucosa has also been associated with invasive fungal sinusitis, as well as obliteration of the retroantral fat planes. Both soft tissue and bone windows, as well as high-resolution axial and coronal views, are necessary. Magnetic resonance imaging (MRI) is useful for evaluating intracranial extension and extension beyond the paranasal sinuses.
Labs
Cultures are inadequate and play no role in the initial diagnosis and management of suspected acute invasive fungal rhinosinusitis. Positive culture results will most likely be available late in the course of the disease. Useful labs for assessing risk factors include a complete blood count (CBC), absolute neutrophil count, chemistries, blood glucose and hemoglobin A1C (HbA1c) in diabetics, and human immunodeficiency virus (HIV) testing with CD4 lymphocyte counts and viral load in AIDS patients.
Pathology
Biopsy of the middle concha or other suspicious lesions with immediate frozen-section analysis is the gold standard test to confirm the presence of tissue-invasive fungus. Mucor is identifiable within the mucosa as large, irregularly shaped nonseptate hyphae that branch at right angles. Aspergillus is identifiable as smaller hyphae that are septate and that branch at 45° angles. Methenamine silver stain is performed to confirm the diagnosis; however, these results may not be available for several hours.
Treatment Options
This is a surgical emergency: complete surgical resection and the reversal of underlying immune dysfunction are critical. The diabetic patient can be successfully treated with early diagnosis, insulin drip, and wide surgical resection. In the oncology patient, if neutropenia cannot be reversed, mortality is high. Granulocyte-macrophage colony-stimulating factor (GM-CSF) may be useful. Surgical goal is resection of all involved tissue. This may be accomplished endoscopically in select cases. However, an extended total maxillectomy with orbital exenteration may be necessary in advanced disease. Systemic antifungals as well as intranasal nebulized amphotericin are administered, but these should be considered adjuvant therapy.
Outcome and Follow-Up
Prognosis is very poor with intracranial involvement. A bone marrow transplant patient with uncorrectable neutropenia has a poor prognosis. Overall survival in diabetic patients may approach 80% if ketoacidosis is corrected.
4.1.2 Orbital Complications of Sinusitis
Key Features
Sinusitis is a common cause of orbital infection.
Significant morbidity and even mortality can result.
Orbital extension of sinusitis is most common in pediatric patients.
Combined otolaryngology and ophthalmology care is required.
Orbital extension of sinonasal disease requires immediate attention, as rapid progression and blindness may occur. Anatomically, the orbit is bounded by all paranasal sinuses, and infection may spread to the orbit directly or via retrograde thrombophlebitis. The Chandler classification system is heuristically useful in staging and managing orbital complications of sinusitis ( Table 4.2 ). Hospital admission and intravenous antibiotic therapy are required for treatment; surgical drainage is necessary in the event of abscess formation, vision compromise, or lack of improvement with medical therapy.
Stage | Description |
I | Preseptal cellulitis |
II | Orbital cellulitis |
III | Subperiosteal abscess |
IV | Orbital abscess |
V | Cavernous sinus septic thrombosis |
Epidemiology
Orbital complications occur in ~3% of sinusitis cases. These are most common in children but can occur at any age. Subperiosteal abscess is present in ~20% of cases of orbital extension of sinusitis. Cavernous sinus thrombosis is rare. Immunosuppressed patients are at increased risk and require aggressive treatment.
Clinical
Signs and Symptoms
The most common findings are orbital edema, pain, proptosis, and fever. Orbital disease may be the first sign of sinusitis in children. In more advanced cases, there may be gaze restriction and visual acuity change.
Differential Diagnosis
In the pediatric age group, orbital pseudotumor consists of painful proptosis without a fever or leukocytosis. Orbital rhabdomyosarcoma may present with inflammatory changes in 25% of patients. An ethmoid mucocele may present with proptosis, and CT will reveal an expanded sinus in this instance. Other sinonasal causes of proptosis or orbital edema include allergic fungal rhinosinusitis and neoplasm as well as iatrogenic injury. Abnormal thyroid state may cause ophthalmopathy.
Evaluation
Physical Exam
Examination requires the combined input of the otolaryngologist and the ophthalmologist. In general, the patient will have a history of preceding sinusitis or current complaints consistent with acute sinusitis. Fever is usually present. Head and neck exam reveals lid or periorbital edema, erythema, and tenderness. In cases of preseptal (periorbital) cellulitis, the remainder of the eye exam is normal. The presence of proptosis, chemosis, extraocular muscle limitation, diplopia, or decreased visual acuity suggests orbital cellulitis or subperiosteal abscess. With cavernous thrombosis or intracranial extension, findings may include a frozen globe (ophthalmoplegia), papilledema, blindness, meningeal signs, or neurologic deficits secondary to brain abscess or cerebritis. Superior orbital fissure syndrome is a symptom complex consisting of retroorbital pain, paralysis of extraocular muscles, and impairment of first trigeminal branches. This is most often a result of trauma involving fracture at the superior orbital fissure, but dysfunction of these structures can arise secondary to compression. Orbital apex syndrome adds involvement of the optic nerve.
Imaging
Contrast-enhanced computed tomography (CT) scanning with coronal and axial views is the imaging study of choice if there is any suspicion of postseptal involvement (i.e., other than simple periorbital cellulitis). A subperiosteal abscess is identifiable as a lentiform, rim-enhancing hypodense collection in the medial orbit with adjacent sinusitis. The medial rectus is displaced. In the absence of abscess formation, there may be orbital fat stranding, solid enhancing phlegmon, or swollen and enhancing extraocular muscles, consistent with orbital cellulitis. A lid abscess may be present, less commonly. Suspicion of cavernous sinus thrombosis is better evaluated with magnetic resonance imaging (MRI).
Labs
A complete blood count (CBC) with differential may be useful. Preoperative labs should be ordered as indicated.
Pathology
In younger children, microbiology often consists of single aerobic species including alpha Streptococcus, Haemophilus influenzae, or coagulase-positive Staphylococcus. In those over 10 years old, organisms are often mixed and may include anaerobes.
Treatment Options
Medical
All patients should be admitted and treated with serial ophthalmologic exams and intravenous (IV) antibiotics that have good cerebrospinal fluid (CSF) penetration. Generally, a third-generation cephalosporin is used. Oxacillin is often used in children. Older patients are often double-covered with clindamycin for anaerobes. Alternatives include ampicillin/sulbactam, vancomycin, or aztreonam. Antibiotics are adjusted according to cultures, if possible. Systemic steroids are not recommended. Topical nasal vasoconstrictors are useful (i.e., oxymetazoline).
Surgical
A majority of patients with orbital complications require surgery. This is an area of some controversy. Clearly, surgical drainage is required urgently for abscess formation or decreased visual acuity. If the clinical setting allows for close follow-up (i.e., frequent serial ophthalmologic assessment), many clinicians will observe certain cases of preseptal or early postseptal cellulitis. If there is any progression or lack of resolution with medical therapy over 48 hours, surgery is recommended. Surgical drainage may be accomplished endoscopically by experienced surgeons; however, consent for an external ethmoidectomy approach is recommended. Also, the location of certain abscesses may be amenable to external drainage by ophthalmologist. Regardless of approach, the abscess should be drained and the underlying sinus disease should be addressed. For cavernous thrombosis, involved sinuses, including the sphenoid, must be drained; systemic anticoagulation remains controversial.
Stay updated, free articles. Join our Telegram channel
Full access? Get Clinical Tree
