A nose piercing infection should heal fully within 4 to 8 weeks depending on how severe the infection is.
The nose piercing infection though should begin healing within 3 days of treatment but it can take awhile for it to heal fully.
If the nose piercing infection is not healing within 8 weeks or gets worse then you should go to urgent care or the emergency room or your doctor for treatment.
Most times though the nose piercing infection heals up without any medical attention and home treatment.
You should keep the nose piercing infection area clean and use soap and a slat solution to clean the area or apply some apple cider vinegar with a cotton swab to the affected area.