3) Certain drugs
Many anti allergic drugs stop sneezing and nasal blockage by decreasing nasal glands secretions. This helps alleviate symptoms, but these secretions also keep the nose humid and the mucus lining healthy. Excessive nasal dryness can occur with local steroids and antihistamines. Steroids have a more pronounced effect since they directly decrease mucosal healing. Cocaine inhalation can also cause a more severe effect since cocaine is a severe vasoconstrictor. It can be potent enough to cut all blood supply to the nasal septum causing gangrene and nasal septal perforation.