Hi Nasal crusting is caused by abnormal mucus production or excessive accumulation. The mucus is thick and does not drain normally. Minimal crusting can occur even in normal persons.Large crusts may form which may interfere with breathing or emit a foul odor. Avoid picking the nose often.Applying a warm, wet washcloth over the nose several times a day will be helpful.Using saline nasal spray as needed to help with pain and encourage the scab to heal. Hope that was helpful.Let me know if i can assist you further. Regards Dr.Saranya Ramadoss General and Family Health Physician