Frequency of preauricular sinus differs depending the population: 0.1-0.9% in the US, 0.9% in the UK, and 4-10% in Asia and parts of Africa. Comparative frequency is known to be higher in Africans and Asians than in Caucasians. Preauricular sinuses are inherited features, and most often appear unilaterally.
Rhinitis is inflammation of the nasal cavity lining (inside the nose). It is often caused by allergies. It may also be caused by environmental factors such as pollution, weather changes, stress, infections, and som...
The nasal cavity can be examined in vivo either through a nostril or through the pharynx. A nasal speculum in a nostril is used in anterior rhinoscopy. A postnasal mirror inserted into the pharynx through the mouth enables the choanae to be inspected in posterior rhinoscopy (figs. 52-4 and 53-11 B).