View Abstract

A6748 - Croup in Adults: All Bite and No Bark?
Author Block: P. P. Patel, C. Jacob, G. S. Thind, M. Loehrke; Internal Medicine, Western Michigan University Homer Stryker M.D. School of Medicine, Kalamazoo, MI, United States.
Introduction:Croup, or acute laryngotracheitis, is well defined as a pediatric illness but remains an uncommon cause of respiratory distress in adults. Adult croup syndrome takes a more severe disease course than in children, usually requiring definitive airway management and intensive care monitoring. We report a case of croup caused by respiratory syncytial virus (RSV) in an immunocompromised adult patient.
Case description:A 61-year-old female with a history of recently diagnosed diffuse large B-cell lymphoma (DLBCL) and asthma presented to the hospital with worsening stridor, hoarseness, cough, and dyspnea for five days. Her most recent cycle of chemotherapy was about three weeks prior to presentation. She noted encounters with her grandchildren who had prodromal symptoms of upper respiratory tract illnesses. Her physical exam was remarkable for tachypnea, inspiratory stridor without retractions, and bilateral wheezes. Initial labs revealed neutropenia, lymphopenia, and anemia, but were otherwise unremarkable. Imaging of the neck revealed subglottic narrowing on X-ray, with computed tomography identifying soft-tissue swelling along the left supraglottic airway extending to the glottis. Emergent fiberoptic laryngoscopy was performed. A normal epiglottis was visualized, with a mucosalized mass on the left aryepiglottic fold of the larynx with adjacent vocal cord hypomobility. The patient was started on dexamethasone. Given concern for spread of her DLBCL, the region of supraglottic swelling was biopsied several days after therapy and later found to have benign edematous squamous mucosa. A rapid multiplex polymerase chain reaction (PCR) was done, which was positive for RSV. Her croup was treated with a steroid taper, with significant improvement of her presenting symptoms. Four weeks later, repeat fiberoptic laryngoscopy revealed resolution of focal areas of swelling.
Discussion:RSV and other viral infections are recognized as common etiologies for croup in children, but are exceedingly rare in adult populations. Of the fourteen adult croup cases identified in our literature review, only two have confirmed viral etiologies. Consistent with factors reported by Tong et al., our patient's chemotherapy-treated DLBCL likely resulted in a poor cell-mediated response--a mechanism which normally prevents viral growth in the laryngotracheobronchial structures of healthy adults. Our case highlights the importance of early recognition of acute laryngotracheitis in immunocompromised adults, with prompt initiation of steroids, and if indicated, supportive oxygenation and nebulized epinephrine to prevent airway obstruction and subsequent endotracheal intubation. Additionally, the use of multiplex PCR assays allows the recognition of viral etiologies of croup, and fosters appropriate antibiotic use.