A blister on a baby’s lip can be alarming for parents, but it is a benign and common occurrence. These small bumps are frequently related to the mechanical action of feeding in infants. Many lip blisters are harmless and resolve without intervention. Identifying the specific characteristics of the blister helps determine if it is a normal part of development or a sign of an underlying health issue.
Sucking Blisters: The Benign and Common Cause
The most frequent cause of lip blisters in infants is the vigorous sucking action required during feeding. These are often referred to as sucking blisters or milk blisters and function similarly to a small callus. Friction causes the outer layer of skin to separate and fill with fluid.
These friction-related blisters typically appear as a single, clear bump, usually located centrally on the upper lip. They are not painful to the infant. Sucking blisters are often transient, meaning they can appear, disappear, and reappear over the course of a few days or weeks as the infant’s feeding technique matures.
The presence of a sucking blister does not automatically indicate a poor latch during breastfeeding or bottle-feeding. These blisters are an expected result of the powerful suction reflex and the soft, delicate nature of a newborn’s skin. No treatment is necessary for these blisters, as they will heal naturally once the skin adapts to the repeated pressure.
Identifying Blisters Resulting From Infection
Blisters not caused by friction often signal an infection. One concerning cause is the Herpes Simplex Virus (HSV). HSV blisters usually appear as a cluster of small bumps, often located on the lip border or around the mouth, rather than the central upper lip.
HSV infection in newborns can be severe. A baby with HSV may exhibit a high fever, extreme irritability, or profound lethargy and may refuse to feed. Prompt medical attention is required immediately if clustered blisters are present along with any of these accompanying signs.
Another infectious cause is Hand-Foot-and-Mouth Disease (HFMD). HFMD typically presents with blisters not only on the lips but also inside the mouth and throat, which can make swallowing painful. The characteristic rash is also found on the palms of the hands and the soles of the feet.
A child with HFMD often develops a fever before the rash appears. While the infection is generally mild in older children, the painful mouth sores can lead to a refusal to drink, making dehydration a serious risk in infants. The location of the sores, coupled with a history of fever, helps determine the correct diagnosis.
When and How to Address Baby Lip Blisters
Seeking medical attention depends on the blister’s appearance. A single, non-painful, clear blister on the central lip that comes and goes is likely a benign sucking blister. Parents should ensure the area remains clean and avoid attempting to pop the blister, which could introduce bacteria.
Medical consultation is necessary if the lip blister is accompanied by concerning symptoms. These red-flag symptoms include a fever, extreme fussiness, or lethargy. Blisters that appear in clusters, are yellow or crusted, or are present inside the mouth should also prompt an immediate call to a healthcare provider.
If the infant is not feeding adequately or is showing signs of dehydration, such as significantly fewer wet diapers, medical intervention is needed. In cases of infectious blistering, early diagnosis and treatment are important. Do not wait for the blister to resolve if the infant exhibits any indication of systemic illness or feeding difficulty.