What condition involves subglottic narrowing of the airway, suggestive of steeple sign?

The condition that involves subglottic narrowing of the airway, suggestive of the steeple sign, is croup. This respiratory condition is characterized by inflammation and swelling of the larynx and subglottic area, typically caused by a viral infection. The steeple sign, which can be seen on a neck X-ray, resembles a church steeple and indicates the narrowing of the airway typically seen in croup. Clinically, patients often present with a distinct barking cough, stridor, and respiratory distress.

In the context of other conditions, meningitis primarily affects the central nervous system and would not typically present with signs of airway narrowing. Shoulder dystocia relates to childbirth complications and does not involve airway issues, and myocardial infarction pertains to heart problems, which also would not show signs related to the airway. Thus, croup is the clear match for this description, as it uniquely involves the airway changes associated with the steeple sign.