Racemic epinephrine will break the attack if needed. The major differential diagnosis is between spasmotic croup and viral croup. Complications are exceedingly rare. Diphtheria is a rare cause. The illness is generally quite mild with sore throat, hoarseness, cough, and possibly mild inspiratory stridor.
Respiratory distress is rare with the exception of young infants.
If diphtheria is the cause, respiratory distress with airway compromise is quite marked secondary to the pseudomembrane blocking the laryngeal inlet . Complete obstruction and respiratory arrest may occur. Fortunately, immunization for diphtheria in the United States has made this disease extremely rare. Diagnosis is made by history and physical examination. The physical examination may show some minor erythema and minimal edema of the supraglottic structures.