Transverse nasal crease Transverse nasal crease The transverse nasal crease or groove is a usually white line between the upper two-thirds and the lower third of the human nose (slightly above the cartilage tip between the bridge and nostrils). It can occur as the result of heredity, accident, or the constant rubbing or wiping of the nose, commonly referred to as the allergic salute. In addition to cases caused by heredity, physical injury, the transverse nasal crease is common in children and adults with chronic nasal allergies. People with allergies often use their hands to remove mucus from a runny nose or rub
Mucus normal breathing. Further distinction exists between the superficial and cell-lining layers of ASL, which are known as mucus layer (ML) and pericilliary liquid layer (PCL), respectively. "Phlegm" is a specialized term for mucus that is restricted to the respiratory tract, whereas the term "nasal mucus" describes secretions of the nasal passages. Nasal mucus is produced by the nasal mucosa; and mucus lining the airways (trachea, bronchus, bronchioles) is produced by specialized airway epithelial cells (goblet cells) and submucosal glands. Small particles such as dust, particulate pollutants, and allergens, as well as infectious agents and bacteria are caught in the viscous