What should you know about dry skin corner of lips?

The mouth corners repeatedly stretch during speaking and eating. Saliva can collect there, soften the surface, and then leave it dry as it evaporates. Lip licking, cold air, wind, drooling during sleep, dental appliances, and fragranced lip products may add irritation. Atopic dermatitis, psoriasis, or asteatotic eczema can also affect nearby skin, so redness, scaling, itch, and recurrence matter.

A single dry split is different from a persistent sore with crusting, swelling, or discharge. Note whether both corners are affected and whether the problem follows a new toothpaste, balm, or cosmetic.

Rinse gently and pat dry after eating. Apply a plain, fragrance-free ointment to the corners several times through the day and before sleep; emollient therapy can reduce water loss. Avoid licking, picking, mentholated balms, and fragranced cosmetics until the skin settles. Keep the area dry without rubbing and use sun protection around, rather than directly over, an open split.

See a clinician if cracking lasts, repeatedly returns, spreads beyond the corners, or makes eating difficult despite barrier care. Prompt assessment is needed for marked swelling, pus, honey-coloured crust, fever, eye involvement, or rapidly worsening pain. Treatment depends on whether irritation, eczema, infection, or another cause is present.

What is causing the corner cracks? Could my toothpaste, lip product, saliva, or dental appliance be contributing? Which ointment is suitable? Do I need treatment for eczema or another condition?