Arhinia refers to congenital failure of the external nose, nasal cavity, and olfactory apparatus to develop. It is an extremely rare condition that can be detected on prenatal ultrasound or MRI.
Arhinia may occur in a syndromic setting (such as ethmocephaly), but it has been reported to occur sporadically.
Results from a fetal insult at 3-8 weeks gestational age.
Absence of the soft tissues of the nose can be detected on a second trimester ultrasound study and confirmed with fetal MRI, if desired. Midfacial flattening of the facial profile and a prominent upper lip can be seen .
Both partial arhinia and total arhinia have been reported.
Treatment and prognosis
Treatment involves managing the nasal cavity airway and managing subsequent feeding difficulties. Surgical reconstruction can be performed at a later date.