What specifically causes a nasal crease as seen in allergic rhinitis?

A nasal crease, often referred to as the "allergic salute," is specifically caused by the habitual rubbing of the nose, typically done with the palm of the hand. This repetitive motion can lead to a distinct horizontal line or crease developing on the skin across the bridge of the nose. It is commonly associated with individuals who experience allergic rhinitis, as they may frequently rub or push up their noses due to itching or discomfort caused by allergens.

While constant sneezing can be a symptom of allergic rhinitis, it is not the direct cause of the nasal crease. Chronic nosebleeds are more related to underlying issues with the nasal mucosa but do not contribute to a crease. Exposure to allergens can lead to the symptoms of allergic rhinitis itself, but does not specifically result in the physical manifestation of a nasal crease. Thus, the act of rubbing the nose, typical in response to nasal symptoms, is what directly leads to the formation of the nasal crease.