Mouth sores, which might appear as white patches, blisters, or red spots, are common in babies and can make feeding or comforting an infant difficult. Understanding the cause and implementing safe, gentle care strategies is a primary concern for parents. This guide clarifies how to identify the most common causes of these oral irritations and outlines immediate steps for a baby’s comfort and healing.
Identifying the Most Common Causes
Oral thrush, a fungal infection caused by an overgrowth of the yeast Candida albicans, is one of the most frequent culprits behind mouth sores in infants. It typically presents as creamy white patches on the tongue, inner cheeks, and gums that often resemble cottage cheese. A distinguishing feature of thrush is that these patches cannot be easily wiped away and attempting to remove them may reveal red, sensitive tissue underneath.
A viral infection known as Herpetic Gingivostomatitis, caused by the Herpes Simplex Virus Type 1 (HSV-1), is another common cause, often presenting with fever first. This condition results in numerous small, painful blisters that quickly turn into ulcers on the gums, tongue, and inner lips. Unlike simple irritation, this viral infection frequently makes the gums look swollen and bright red, causing significant discomfort that interferes with feeding.
Hand, Foot, and Mouth Disease (HFMD), caused by enteroviruses like coxsackievirus, creates small, blister-like lesions usually located toward the back of the mouth and throat. These oral sores are generally accompanied by a distinctive non-itchy rash of small red spots or blisters on the palms of the hands and soles of the feet. Minor trauma, such as aggressive wiping of the gums, injury from a hard toy, or a slight burn from warm milk, can also create isolated, non-infectious mouth sores.
Immediate Home Treatment and Relief
Home care focuses on managing pain and ensuring adequate hydration, as mouth sores often make swallowing painful. Pediatrician-approved over-the-counter pain relievers, such as weight-based doses of Acetaminophen, can be used to reduce fever and oral discomfort. Ibuprofen is also an option for babies six months and older, but always confirm the correct dosage with a healthcare provider, as dosing is strictly determined by the baby’s current weight.
Avoiding the use of topical numbing gels, such as those containing benzocaine, for oral pain in infants and young children is a necessary safety measure. The U.S. Food and Drug Administration (FDA) has issued warnings against these products because they have been linked to a rare but serious condition called methemoglobinemia, a blood disorder that dangerously reduces the amount of oxygen carried through the blood. Given that these topical agents provide minimal relief before washing away, the risk outweighs the benefit.
Hydration is important. Offer breast milk, formula, or an oral rehydration solution like Pedialyte frequently in small amounts to encourage fluid intake without overwhelming the baby. Soft, cool foods such as pureed fruits, yogurt, or cold applesauce are often tolerated better than warm or textured foods. Avoid highly acidic foods, like citrus, and salty snacks, as these can sting the sensitive mouth lesions.
Maintaining good oral hygiene helps prevent the spread of infectious sores and promotes healing. For a suspected fungal infection like thrush, sterilize pacifiers, bottle nipples, and any toys that enter the mouth by boiling them for five to ten minutes or running them through a dishwasher’s hot cycle. Gently cleaning the baby’s mouth with a soft, clean cloth or a finger brush after feedings can help keep the area clean and minimize irritation.
Knowing When to Contact a Pediatrician
While most mouth sores resolve with supportive home care, certain symptoms indicate the need for professional medical evaluation. The primary risk is dehydration, which occurs when a baby refuses to drink enough fluids. Signs of dehydration include a significant reduction in wet diapers, fewer than three wet diapers in a 24-hour period, or a dry mouth with little or no tears when crying.
A persistent fever, a rectal temperature of 100.4°F (38°C) or higher in an infant under three months old, requires immediate medical attention. For older babies, a high fever or one that persists for more than 72 hours should prompt a call to the doctor. Other red flag symptoms include excessive lethargy, unusual irritability, or sores that appear to be worsening or do not begin to heal after several days of diligent home treatment.
A medical professional can examine the sores to confirm the cause, which is necessary for prescribing targeted treatment. For example, a confirmed case of oral thrush requires a prescription for an antifungal liquid, such as Nystatin, which is administered directly to the lesions. In rare cases of severe Herpetic Gingivostomatitis, an antiviral medication may be prescribed to shorten the duration of the infection.