"What should I do if my son has a red and irritated area under his nose?"

To treat redness under the nose, you can continue using vaseline regularly throughout the day. Additionally, consider addressing the cause of the nasal discharge, which may require nasal hygiene using a saline solution and suction device. If there are other symptoms present, such as sneezing or suspected allergies, it may be helpful to consult a pharmacist for further advice on potential treatment options.