Hello Dear, Welcome to HCM. Understanding your concern. Thanks for your query . The symptoms you mention in your query indicates that you baby has oral thrush .It is very common in babies having weak immune system . There can be other reasons also like if baby is on antibiotics . I would suggest you to consult dentist/pedodontist for proper evaluation and to rule out other condition .Doctor may prescribe antifungal medicines like miconazole and nystatin . Apply antifungal gel prescribed by doctor in your baby s oral cavity with clean hands . Breastfeeding mother should apply antifungal ointment or el prescribed by doctor to nipple before breastfeed. For now what you can do is apply baking soda diluted with water with cotton swab and rinse it, you can also apply tea tree oil which is also very defective. Hope your concern has been resolved. Get Well Soon. Best Wishes, Dr. Harry Maheshwari