PHACE syndrome is a rare condition present at birth in which a large facial birthmark called a hemangioma appears alongside abnormalities in the brain, blood vessels, heart, or eyes. Each letter in the name stands for one of these possible features, and no two children with PHACE are affected in exactly the same way. It is typically suspected when an infant has a hemangioma on the face or scalp larger than 5 centimeters.
What the Acronym Means
PHACE stands for the major body systems the condition can involve:
- P — Posterior fossa malformations: structural differences in the part of the brain near the base of the skull, which controls balance and coordination
- H — Hemangioma: a non-cancerous vascular growth, typically large and segmental, on the face, neck, or scalp
- A — Arterial anomalies: abnormalities in the arteries of the brain and neck
- C — Coarctation of the aorta and cardiac defects: narrowing of the body’s main artery or other heart abnormalities
- E — Eye abnormalities: differences in the structure or function of the eyes
When abnormalities of the breastbone are also present, the condition is sometimes called PHACES, with the “S” standing for sternal malformations. Some children also have midline differences like sternal pits or clefts in the skin above the navel.
The Hallmark Birthmark
The most visible sign of PHACE syndrome is a large infantile hemangioma on the face, neck, or scalp. These growths appear as red or bluish soft masses that cover a wide area of skin, or as clusters of smaller raised spots arranged in a pattern. They tend to follow the distribution of facial nerves, often along the forehead, cheek, or jaw.
Not every facial hemangioma signals PHACE. The condition is suspected when the hemangioma is segmental (covering a broad territory rather than forming a small, round bump) and measures more than 5 centimeters across. Among infants with large segmental facial hemangiomas, studies estimate that anywhere from 5% to over 20% will meet the diagnostic criteria for PHACE, depending on the population studied and how aggressively screening is done.
How It Affects the Heart and Blood Vessels
Cardiovascular problems are among the most common features beyond the hemangioma itself. In a registry study of 150 children with PHACE, 41% had some type of heart or blood vessel abnormality. The most frequent finding was an abnormal origin of a subclavian artery, one of the vessels that supplies blood to the arms, present in about 21% of patients. Coarctation of the aorta, a distinctive long-segment narrowing of the aortic arch, was the second most common cardiovascular issue at 19%.
The pattern of aortic narrowing in PHACE looks different from the typical coarctation seen in other children. It tends to involve a longer stretch of the arch with areas of widening next to the narrowed segments. About 31% of those with cardiovascular involvement also had a ventricular septal defect, a small hole between the lower chambers of the heart. Severe or complex heart defects were rare, occurring in only 3 of 62 affected children in that registry.
Brain and Artery Differences
Abnormalities of the arteries that supply the brain and neck are very common in PHACE, reported in up to 91% of patients in one study. These can include narrowed, absent, or unusually shaped arteries. While the anatomy can look concerning on imaging, the actual risk of stroke turns out to be low. In a long-term study of 104 patients followed past age 10, only 2 (1.9%) experienced an ischemic stroke.
Structural differences in the brain itself, particularly in the posterior fossa region at the base of the skull, can also occur. This part of the brain houses the cerebellum, which coordinates movement and balance. The severity of these malformations varies widely, from findings only visible on imaging to differences that affect motor development.
Eye and Endocrine Involvement
Eye abnormalities show up in roughly 6% to 26% of children with PHACE, particularly in those whose hemangioma involves certain segments of the upper face. The range of findings is broad: some children have structural differences in the eye itself, while others develop vision issues related to the hemangioma pressing on or near the eye socket. Early treatment of the hemangioma may help reduce the risk of these complications by shrinking the growth before it distorts surrounding structures.
A smaller subset of patients develops endocrine problems, including growth hormone deficiency or thyroid issues. These can be easy to miss in infancy. If a child with PHACE shows slowed growth, developmental delays, or later on, delayed puberty, endocrine testing is an important step.
How PHACE Is Diagnosed
A formal diagnosis requires both the characteristic hemangioma and evidence of involvement in at least one other body system. Consensus criteria define two categories: a “definite” diagnosis requires a facial hemangioma larger than 5 centimeters plus one major criterion (a significant finding in one of the affected organ systems) or two minor criteria. A “possible” diagnosis requires the same hemangioma plus one minor criterion.
When PHACE is suspected, the standard workup includes an MRI and MRA of the head and neck to evaluate brain structure and blood vessel anatomy, plus an echocardiogram to check the heart and aortic arch. These imaging studies are essential because many of the internal abnormalities produce no visible symptoms in infancy. A child can have significant arterial narrowing or a heart defect without any outward signs.
Treating the Hemangioma
The first-line treatment for problematic infantile hemangiomas is an oral medication called propranolol, a type of beta-blocker that shrinks the growth by reducing blood flow to it. In PHACE syndrome, there was initially concern that lowering blood pressure with propranolol could reduce blood flow to the brain in children who already have narrowed arteries, potentially raising stroke risk.
A study of 76 children with PHACE treated with propranolol found no strokes, transient ischemic attacks, or serious cardiovascular events during treatment. The most common side effects were minor: sleep disturbances, mild stomach issues, and respiratory symptoms. Rare cases of low blood sugar, slow heart rate, or low blood pressure were caught incidentally and resolved without intervention.
Because of the potential risks, children with PHACE typically undergo a heart ultrasound before starting propranolol to rule out aortic coarctation that could make the medication dangerous. Dosing usually starts low and is given multiple times a day to avoid sharp drops in blood pressure. Topical beta-blocker eye drops, sometimes used for small hemangiomas near the eye, are generally avoided in PHACE patients because they can be absorbed into the bloodstream and compound the effects of the oral medication.
Long-Term Outlook
PHACE syndrome is a lifelong condition, though the hemangioma itself typically shrinks over the first several years of life. What remains varies: some children are left with skin texture changes or discoloration where the growth was, while others need procedures to address residual tissue.
The longer-term picture involves more than the skin. In a study of patients over age 10, 72% reported headaches or migraines. Learning differences were common, with 45% of participants reporting them and about 39% requiring individualized education plans at school. Progressive changes in blood vessel anatomy can also continue over time, which is why ongoing monitoring with imaging is part of long-term care.
The arterial abnormalities, while widespread on imaging, rarely cause catastrophic events like stroke. The bigger day-to-day impact for many families is managing headaches, supporting learning needs, and keeping up with the recommended schedule of heart and brain imaging to catch any changes early.