Ingested foreign body. Acute otitis media. Laceration of the oral cavity.
Most nasal discharge is due to the common cold.
Allergic rhinitis is more likely to cause a blocked nose, but may cause chronic nasal discharge, often with nasal itch and sneezing. Persistent unilateral nasal discharge, often foul-smelling, may be due to foreign body. This can often be removed under direct vision using nitrous oxide. In the lower oesophagus a foreign body may cause reflex vomiting. Look for air in the mediastinum, which indicates oesophageal perforation.