My 15 month old has had croup twice in a month is this a sign of asthma or allergies?

Not necessarily.: If your toddler's history is not consistent with croup, other diagnoses for stridor should be considered: stridor lasting for short durations (hours); stidor lasting longer than infectious period; stridor not associated with acute infection; severe episodes requiring emergency room visits or hospitalizations; progressively more severe or frequent episodes of croup; choking or gagging before onset.

No: Croup is a most often a viral illness that more severely affects younger children due to the size of their airways. It causes swelling below the vocal cords which then manifests itself physically with the signs of the croupy cough and occasionally inspiratory stridor (loud coarse breathing in). The larger the airway, the less chance of problems and there is no association with asthma/allergies.