Common causes include sucking blisters from breastfeeding or bottle-feeding, where friction forms calluses on the lips. Some babies are even born with these from sucking in the womb. These usually heal on their own.

Other causes can be more serious. Cold sores, caused by the Herpes Simplex 1 virus, are dangerous for newborns and require immediate medical attention. Impetigo, a bacterial infection, creates crusty or fluid-filled blisters and also needs treatment. Oral thrush, a yeast overgrowth, causes white patches inside the mouth and lips, making it painful to suck. Allergic reactions to foods or products can also trigger lip blisters.

Signs of concern include fever, crusting, smelly discharge, or spreading blisters.

Treatment depends on the cause. Sucking blisters need no treatment, though breast milk or coconut oil may soothe dry lips. Infections like cold sores, impetigo, or thrush need medication. Always consult your pediatrician.

Prevention includes good feeding techniques and avoiding contact with infectious sources. When in doubt, seek medical advice to keep your baby safe and comfortable.