In children, possible clinical features include:
- patient is usually 2 to 6 years old; croup occurs in a younger child - 2 or under
- unwell; grey in colour - the child looks septic
- voice is muffled
- if the child coughs it may sound like a "quack"
- child is quiet and terrified
- increasing dysphagia
- drooling
- stridor - of rapid onset and the child will prefer to sit upright and lean slightly forwards in an attempt to maintain the airway. The stridor may be fairly quiet.
In adults, possible clinical features include:
- as above, except that the onset is usually slower; the recovery is also slower
- the principal complaint may be of a severe pain that is worse on swallowing.
This condition may be fatal in either children or adults.