Croup is an acute respiratory infection characterized by inflammation and swelling in the larynx (voice box) and trachea (windpipe). This swelling narrows the upper airway, producing distinctive respiratory symptoms. While widely considered a childhood illness, it can occur in adults. Adult croup, though rare, presents a unique clinical challenge due to differences in adult respiratory anatomy.
Why Croup Manifests Differently in Adults
Croup is uncommon in adults because of the size and structure of the airway. Young children have significantly smaller windpipes, meaning even a small amount of inflammation can cause severe breathing difficulty. In contrast, the adult trachea is larger and more rigid, which means the same degree of swelling has a less dramatic obstructive effect on airflow.
Because an adult’s airway is wider and supported by rigid cartilage, the inflammatory swelling is often tolerated better without immediate respiratory distress. The common viral causes, such as parainfluenza viruses, respiratory syncytial virus (RSV), or influenza, are the same for both age groups, but the host response is modulated by these anatomical differences.
Recognizing the Distinct Symptoms in Adults
Despite the anatomical advantage, adults who contract croup often report severe symptoms. The most recognizable sign is the seal-like “barking” cough, although it may be less pronounced than the classic pediatric presentation. This cough results from air being forced through the swollen vocal cord area.
A high-pitched, harsh sound known as stridor is often present, particularly when breathing in, resulting from the upper airway narrowing. Hoarseness and a change in voice are also frequent complaints, accompanying the cough. Adults with croup commonly experience significant dyspnea, or difficulty breathing, which may be mistaken for other conditions like asthma exacerbation or severe laryngitis. Upper respiratory tract symptoms, such as a runny nose, sore throat, and fever, usually precede the onset of the characteristic cough and stridor by a few days.
The Diagnostic Process and Treatment Approaches
Diagnosing croup in adults begins with a thorough clinical examination, where a physician listens for the distinctive stridor and barking cough. Imaging studies, such as a neck X-ray, may be performed primarily to rule out other serious causes of upper airway obstruction, like epiglottitis or foreign body aspiration.
Treatment is focused on reducing inflammation and maintaining an open airway. Corticosteroids, such as a single dose of oral dexamethasone, are standard to decrease swelling. For moderate to severe cases, nebulized treatments like epinephrine may be administered to rapidly shrink the swollen tissues.
Patients presenting with severe stridor, difficulty speaking, or signs of respiratory fatigue often require immediate medical intervention and possibly hospitalization for close monitoring. In the most severe instances, where the airway is compromised, temporary placement of a breathing tube may be necessary to ensure adequate oxygenation. Mild cases are sometimes manageable at home with supportive care like humidified air and staying well-hydrated.
Recovery Timeline and Outlook
The symptoms of adult croup often resolve within three to seven days after the onset of the characteristic cough. The most intense symptoms typically peak around the second or third night and then gradually begin to improve. The distinctive cough, however, may linger for a week or slightly longer.
The overall outlook for adult croup is favorable, with the expectation of a complete recovery. While the illness can be uncomfortable and occasionally requires hospitalization for aggressive airway management, it rarely leads to long-term complications. Prompt medical evaluation and appropriate treatment are typically effective in managing the airway inflammation.