In what sounds like an episode of House, a report detailing the case of a young boy who had experienced nasal congestion and a mysterious "foul odor" whenever he blew his nose for years has been published in JAMA Otolaryngology-Head and Neck Surgery.
The study states that the then 15-year-old boy visited the doctors for the first time in San Antonio about the nasal congestion on both sides of his nose. He also couldn't smell very well. After his nose was examined with an endoscope, it was seen that he had so-called "turbinate hypertrophy" which is an enlargement of narrow passageways called turbinates in the nose. Since this could be caused by mundane problems like seasonal allergies, the doctors prescribed him a nasal spray and antihistamine medication.
While he was told to come back in four to six weeks, he wouldn't turn until he was 16 and started experiencing more adverse symptoms. Not only the congestion had persisted, but he had also started experiencing "a pungent, foul odor" filling the room whenever he blew his nose, Gizmodo reported. "The patient reported that he did not feel he had bad breath, but he was embarrassed that every time he blew his nose there was a foul odor," the authors wrote.
A CT scan showed there was a 0.4-inch-long (9-mm) spherical structure in his nasal cavity. When he underwent surgery for the removal, the foreign body turned out to be a metallic BB pellet.
It was later revealed that he had been shot in the nose with a pellet gun when he was a boy about 8 or 9 years old. Since the boy hadn't experienced any symptoms, his parents hadn't taken him to a hospital and the structure was surrounded by tissue with time, his body starting to grow around it without any outward sign of physical trauma.
If you're curious about the foul smell, study co-author Dylan Z. Erwin, a medical student at The University of Texas Health Science Center at San Antonio, told Live Science that foreign objects stuck in the nose can produce it since "the foreign body causes blockage of natural drainage pathways in the nose, so there is a buildup of mucus, inhaled debris and bacteria."