Acute invasive fungal rhinosinusitis

Mucormycosis is a rapidly progressive, angioinvasive mold infection caused by Rhizopus and Mucor species that thrive in diabetic ketoacidosis, neutropenia, and iron-overload states. Diagnosis rests on biopsy showing broad, nonseptate hyphae in necrotic tissue, and first-line treatment combines urgent surgical debridement with high-dose liposomal amphotericin B, stepped down to posaconazole or isavuconazole; mortality remains 60 to 80 percent.

Invasive aspergillosis is an angioinvasive mold infection of neutropenic and immunosuppressed hosts that begins in the respiratory tract and disseminates hematogenously, diagnosed with CT, galactomannan, and biopsy, and treated first-line with voriconazole.

Diabetic ketoacidosis is a life-threatening hyperglycemic crisis of near-absolute insulin deficiency, most common in type 1 diabetes, producing an anion-gap ketoacidosis from unrestrained lipolysis and osmotic diuresis from severe hyperglycemia. It is diagnosed by hyperglycemia, ketonemia, and an anion-gap metabolic acidosis, and treated with intravenous isotonic saline, an intravenous regular insulin bolus and infusion, and aggressive potassium repletion guided by frequent electrolyte monitoring.

Septic thrombosis of the cavernous sinus from spreading facial, sinus, or orbital infection, marked by fever, proptosis, chemosis, and cranial nerve palsies that classically become bilateral. It is a neuro-ophthalmic emergency treated with immediate broad-spectrum IV antibiotics, source control, and consideration of anticoagulation.

Orbital cellulitis is infection of the fat and muscle posterior to the orbital septum, most often from spreading sinusitis, that causes proptosis, painful ophthalmoplegia, and vision loss and can progress to cavernous sinus thrombosis. It is a vision- and life-threatening emergency treated with admission, blood and tissue culture, orbital/sinus CT or MRI, and immediate empiric IV vancomycin plus ceftriaxone with ophthalmology and ear, nose, and throat (ENT) involvement.

Neutropenic fever is an oncologic emergency defined as a single oral temperature of 38.3 C or higher, or 38.0 C sustained for 1 hour, with an ANC of 500/microL or lower, most often during the chemotherapy nadir. Management is empiric antipseudomonal beta-lactam therapy within 60 minutes, with vancomycin, antifungal therapy, and growth factors added only for specific indications.

Neutropenia is a reduced absolute neutrophil count that raises infection risk sharply once the count falls below 500/microL, most often from chemotherapy or another marrow-suppressing or idiosyncratic drug. Diagnosis rests on a repeat CBC with differential and smear review followed by a directed search for cause, and management centers on stopping the offending agent, treating any underlying disease, and using G-CSF and neutropenic precautions when the count is low or the patient is febrile.

Brain abscess is a focal, ring-enhancing suppurative infection of the brain parenchyma most often from contiguous sinus, ear, or dental spread or hematogenous seeding, diagnosed by contrast MRI and image-guided aspiration and treated with predisposing-source-directed empiric antibiotics plus drainage of abscesses larger than 2.5 cm.

Acute rhinosinusitis is inflammation of the nasal cavity and paranasal sinuses lasting up to 4 weeks, presenting with purulent nasal discharge plus nasal obstruction or facial pain/pressure/fullness. Most cases are viral and treated with acetaminophen/ibuprofen plus nasal saline irrigation alone; a minority are bacterial, identified by persistence beyond 10 days, a biphasic worsening course, or severe onset, and treated with amoxicillin-clavulanate 875/125 mg PO every 12 hours for 5 to 7 days.

Nasal polyps are benign, typically bilateral outgrowths of edematous nasal mucosa driven by chronic mucosal inflammation, most often arising with chronic rhinosinusitis, aspirin-exacerbated respiratory disease, or cystic fibrosis. Unilateral polyps or a mass that does not respond to treatment must be biopsied to exclude tumor.