Bulging Fontanelle

What is a bulging fontanelle?

The human skull is made of many bones, which join together to protect the brain. The lines at which they fuse are called sutures. When a baby is born, these sutures are not yet all firmly joined together. This allows the head to be a bit more flexible as it passes through the birth canal. It also makes it easier for the baby’s brain to grow.

After birth, minerals are added to the sutures, and they begin to slowly close.

The membrane-covered spaces where sutures have not yet closed are called fontanelles, or more colloquially, “soft spots.” The most prominent one is called the anterior fontanelle; it is located at the top of the baby’s head, and typically closes between seven and 19 months of age. In some babies, the posterior fontanelle (at the back of the head) can also be felt; this typically closes between one and two months.

A healthy fontanelle should be firm to the touch and curve slightly inward. Sometimes, if an infant is crying, lying down, or vomiting, it may appear to bulge slightly, but should return to normal when they are in a calm, upright position. If it quickly returns to normal, it is not a true bulging fontanelle.

However, if an infant has a bulging fontanelle (that is, it curves outward) even after you have gotten them to calm down and put them in an upright position, this is a medical emergency. It is especially concerning if the baby also has a fever or appears to be excessively sleepy (1).

What to do when your baby has a bulging fontanelle

If your baby has a bulging fontanelle, do not wait for a doctor’s appointment – go to the nearest emergency room for immediate attention (2).

A bulging fontanelle can be indicative of several serious conditions, including encephalitis (inflammation of the brain, which can lead to permanent brain damage or even death).

What can cause a bulging fontanelle?

It is important to know that a bulging fontanelle can be a sign of several different underlying conditions. Potential causes of a bulging fontanelle include the following (2):

Common causes of a bulging fontanelle include:

Less common causes include:

  • Brain tumor or abscess
  • Lyme disease
  • Addison’s disease
  • Congestive heart failure
  • Leukemia
  • Electrolyte disturbance
  • Hyperthyroidism
  • Male syrup urine disease (the body can’t properly break down proteins)
  • Anemia

How do doctors diagnose the cause of a bulging fontanelle?

In order to determine the cause of a bulging fontanelle, your doctor will perform a physical examination, ask questions about the baby’s medical history, and perform a variety of diagnostic tests.

They will likely ask questions such as the following (1):

  • Which of the fontanelles (soft spots) have appeared to be bulging (e.g. top of the head, back of the head, or elsewhere)?
  • Is the fontanelle consistently bulging, or does it come and go?
  • Does it look normal when the baby is calm or upright?
  • When did you first see the bulging?
  • Does the baby have a fever?
  • Is the baby irritable or lethargic?
  • Are there any other symptoms?

Diagnostic tests may include the following (among others) (1, 2):

  • CT scan
  • MRI
  • Lumbar puncture (spinal tap)

How do doctors treat a baby with a bulging fontanelle?

It is important to realize that a bulging fontanelle can be a sign of more serious conditions. Therefore, to manage a baby with a bulging fontanelle, medical professionals must address the underlying cause. To learn more about how some of the most common causes of bulging fontanelle are treated, please click on the links listed under “Common causes.”

Bulging fontanelle, birth injury, and medical malpractice

Many of the conditions that underlie bulging fontanelles (e.g. encephalitis, hydrocephalus, meningitis, hypoxic-ischemic encephalopathy, intracranial hemorrhage, and head trauma) are types of birth injury. In many cases, these birth injuries are preventable with proper medical care during pregnancy, birth, and the neonatal period.

If a medical professional or organization fails to provide proper care, and this causes harm to the baby, it constitutes medical malpractice. It is also malpractice if a doctor fails to diagnose or take seriously warning signs of injury such as a bulging fontanelle.

Has your child or loved one been harmed by a birth injury that could have been prevented? The attorneys at ABC Law Centers (Reiter & Walsh, P.C.) may be able to help. We focus exclusively on birth injury cases, so we have the legal and medical expertise necessary to effectively advocate for our clients. Please reach out today for a free case review – in fact, you pay nothing throughout the entire legal process unless we win or favorably settle your case.

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  1. Fontanelles – bulging: MedlinePlus Medical Encyclopedia. (n.d.). Retrieved November 2, 2018, from https://medlineplus.gov/ency/article/003310.htm
  2. Bulging fontanelle: Causes, Symptoms and Diagnosis. (n.d.). Retrieved November 2, 2018, from https://www.healthline.com/symptom/bulging-fontanelle