An Unusual Source of Sinonasal Disease in an Immunocompromised Patient: A Case Report of the Clinical Presentation, Diagnosis, and Treatment of Acanthamoeba Rhinosinusitis.

Chronic nasal crusting is a commonly encountered entity in an otolaryngology office. Progressive, extensive nasal crusting with erosion is relatively unusual, however. We present the case a 58-year-old renal transplant patient with a history of vasculitis and immunosuppression who presents with subjective headache and facial pain, nasal crusting, and isolated left ethmoid sinusitis. She developed extensive intranasal necrosis and underwent multiple endoscopic sinus surgeries with intraoperative biopsies, which played a critical role in her workup and eventual diagnosis of Acanthamoeba rhinosinusitis. Although she endured a difficult course, proper diagnosis and treatment allowed for her recovery over time. The differential diagnosis for intranasal necrosis is often broad. This case highlights the wide range of etiologies to be considered in a patient with extensive nasal crusting and erosion/necrosis, and the importance of thorough diagnostic evaluation in these patients, especially those in an immunocompromised state.