What significant sign might be observed in a patient with epiglottitis?

In a patient with epiglottitis, the "thumb sign" is a significant radiographic indicator that can be observed on lateral neck X-rays. This sign reflects the swollen appearance of the epiglottis itself, resembling a thumb due to inflammation and edema caused by infection. The presence of this sign is crucial for the diagnosis of epiglottitis, indicating that immediate medical attention is necessary to prevent airway obstruction.

Other options, such as the steeple sign, pertain more to croup, where the upper airway narrowing is seen in radiographs. Blunting of the costophrenic angles relates to pleural effusion and would not be expected in epiglottitis. The classic pneumonia silhouette is associated with lobar pneumonia and signifies that this condition is separate from the aerodigestive issues that epiglottitis presents. Therefore, the thumb sign is distinctly aligned with the findings in epiglottitis and is a key clinical sign for healthcare professionals to recognize.