Understanding Unilateral Choanal Atresia: Why Was It Missed?

It is incredibly common for unilateral choanal atresia (blockage on only one side of the nasal passage) to go undiagnosed for years ^[1][2]. Unlike babies born with bilateral choanal atresia (blockage on both sides), who experience a life-threatening emergency at birth because newborns are obligate nasal breathers (they must breathe through their nose), your child was able to breathe sufficiently through their one open nostril ^[2][3].

Because there was no immediate respiratory crisis, the signs of a one-sided blockage are often mistaken for common childhood issues like chronic allergies, sinus infections, or even a foreign object stuck in the nose ^[1][4]. Finding this out later is not a failure on your part or a sign of neglect; it is simply the nature of how this condition hides in plain sight ^[1].

What is Choanal Atresia?

Choanal atresia is a congenital (present at birth) condition where the back of the nasal passage—the choana—is blocked by abnormal tissue ^[2].

• Unilateral: The blockage affects only one side.
• Bilateral: Both sides are blocked.
• Composition: The blockage can be purely bony (about 30% of cases), purely membranous (soft tissue), or a mixed combination of both (the most common form) ^[2].

Understanding the Numbers

While rare, this condition follows predictable patterns that can help you feel more grounded in the diagnosis:

• Frequency: It occurs in approximately 1 in every 5,000 to 10,000 live births ^[2].
• Demographics: It is twice as common in females as it is in males ^[2].
• Laterality: Unilateral cases are significantly more common than bilateral ones ^[1].
• Side Preference: When the blockage is on only one side, it is more likely to occur on the right side than the left ^[2].

Identifying the Symptoms

The “classic” symptom that often leads to a diagnosis in older children is persistent, one-sided nasal discharge ^[1][3]. Because the nasal passage is blocked, mucus stagnates and pools in the nose. This trapped fluid can frequently become secondarily infected, leading to thick, discolored, and sometimes foul-smelling discharge ^[1]. This is exactly why doctors often mistakenly look for a “foreign body” (like a bead or a pea) stuck in the nostril first ^[1].

Other signs you may have noticed over the years include:

• Chronic mouth breathing ^[2].
• A persistent “stuffy” feeling that never goes away, even with allergy medication ^[1].
• Noises during sleep or snoring that seem to come from one side.
• The absence of “mist” on a mirror held under the affected nostril (a simple test often used by doctors) ^[1].

Looking Ahead

Now that the diagnosis is confirmed, the goal shifts to opening the airway to improve your child’s quality of life, breathing, and sense of smell ^[5]. The standard treatment is transnasal endoscopic surgery, a minimally invasive procedure where surgeons use small cameras and tools to open the blockage through the nostrils ^[6][7]. Because your child is older, this is typically a planned, non-emergency procedure.

While choanal atresia is sometimes associated with other conditions like CHARGE syndrome (a pattern of birth defects), unilateral cases are much more likely to be “isolated,” meaning they occur on their own without other health issues ^[8][9]. Your care team will likely perform a thorough check to ensure your child’s heart and hearing are normal as part of the routine workup ^[8].

Return to HomePage