Hemangiomas are benign tumors made of extra blood vessels that cluster together in a dense, tangled mass. They’re the most common vascular tumors in infants, appearing in roughly 4.5% of babies, but they also occur in adults in different forms. Most hemangiomas are harmless and many resolve on their own, though some require treatment depending on their size, location, and type.
How Infantile Hemangiomas Develop
Infantile hemangiomas (IH) are the type most people picture: bright red or bluish raised marks that appear on a baby’s skin in the first few weeks of life. They form when blood vessel cells in the skin begin proliferating abnormally, likely triggered by low oxygen levels in the tissue. This oxygen stress causes the body to overproduce signals that drive new blood vessel growth, leading to a rapid buildup of abnormal vessels.
At the cellular level, the endothelial cells lining these vessels carry a specific protein called GLUT1 on their surface. This protein is considered a defining marker of infantile hemangiomas. It distinguishes them from other vascular growths and, interestingly, research has shown these GLUT1-positive cells behave like stem cells. They can convert into different cell types, including fat cells and smooth muscle cells, which helps explain why hemangiomas eventually shrink and leave behind fatty tissue.
The Three Phases of Growth
Infantile hemangiomas follow a predictable life cycle with three distinct stages. During the proliferating phase, from birth through about 12 months, the hemangioma grows rapidly. Growth tends to be fastest in two bursts: one around 1 to 2 months of age and another around 4 to 5 months. Most reach their peak size by about 9 months, though some continue growing until 18 months.
The involuting phase begins around 18 months, when the hemangioma slowly starts to shrink. This stage lasts from roughly age 1 to 5, as the dense mass of blood vessels gradually breaks down and gets replaced by fatty and fibrous tissue. By age 4, about 80% of the original size has typically resolved. The final involuted phase spans from about age 5 to 10, when the hemangioma has finished regressing and the remaining tissue stabilizes.
What’s Left Behind After Involution
Even though most infantile hemangiomas shrink substantially, the skin doesn’t always return to normal. Among superficial hemangiomas that fully resolve, roughly 70% leave behind at least one visible change. The most common residual signs are telangiectasia (small, visible blood vessels on the skin surface), excess fatty tissue, and loose or scarred skin. Thicker hemangiomas are more likely to leave permanent marks. Laser treatments can address some of these cosmetic concerns after the hemangioma has completed its life cycle.
Congenital Hemangiomas: A Different Timeline
Congenital hemangiomas look similar but behave differently. Unlike infantile hemangiomas, which grow after birth, congenital hemangiomas are fully formed at the time of delivery. They test negative for the GLUT1 marker and are caused by different genetic mutations.
There are two main subtypes. Rapidly involuting congenital hemangiomas (RICH) shrink completely by 12 to 14 months of age, often faster than infantile hemangiomas. Non-involuting congenital hemangiomas (NICH) persist indefinitely with little to no regression. A third subtype, partially involuting congenital hemangioma (PICH), falls somewhere in between. These distinctions matter because they determine whether a child needs treatment or simply monitoring.
Cherry Angiomas in Adults
Adults develop their own version of hemangiomas, most commonly cherry angiomas. These are small, dome-shaped red or purple spots that appear on the trunk, arms, and legs. They’re extremely common after age 30 and become more numerous with age. The exact cause isn’t known, but contributing factors include aging, hormonal changes during pregnancy, genetic predisposition, and exposure to certain chemicals like bromides.
Cherry angiomas are completely harmless and don’t require treatment. If you want one removed for cosmetic reasons, the three standard options are electric needle cauterization, freezing with liquid nitrogen, or laser removal. All three are quick outpatient procedures.
Risk Factors for Infantile Hemangiomas
Premature birth and low birth weight are the strongest known risk factors. In one prospective study, 14.3% of very premature infants developed hemangiomas, compared to 3.9% of full-term babies. Very low birth weight infants had a rate of 16.6%, roughly four times higher than those born at normal weight. Female infants are also more commonly affected than males, and Caucasian infants have higher rates than other groups.
How Hemangiomas Are Diagnosed
Most hemangiomas are diagnosed by appearance alone. A doctor can usually identify one based on its look, feel, and growth pattern without any testing. When the diagnosis is uncertain, an ultrasound with color Doppler imaging, which shows blood flow patterns, is typically sufficient to confirm it. Biopsy is rarely necessary and is reserved for cases where the ultrasound findings are ambiguous or the growth doesn’t follow expected patterns.
The clinical timeline is often the clearest clue. A lesion that appears after birth and grows rapidly in the first several months points to an infantile hemangioma. One that’s already fully formed at birth suggests a congenital hemangioma.
When Treatment Is Needed
Since most infantile hemangiomas shrink on their own, many are simply monitored. Treatment becomes necessary when a hemangioma threatens vision (near the eye), airway (in the throat), or causes repeated bleeding, ulceration, or significant disfigurement. Hemangiomas on the nose, lips, or ears are more likely to need early intervention because of the functional and cosmetic risks.
The first-line treatment is oral propranolol, a beta-blocker that slows the hemangioma’s growth and accelerates shrinkage. Treatment typically starts at a low dose that’s gradually increased over a couple of days while monitoring heart rate and blood sugar. The medication is usually continued through the first year of life, then tapered off over two to three weeks. Most children respond well, with visible reduction in size and color within the first few weeks.
PHACE Syndrome and Larger Concerns
Large facial hemangiomas can occasionally signal a more complex condition called PHACE syndrome. The acronym stands for posterior fossa brain anomalies, hemangioma, arterial abnormalities, cardiac defects (particularly a narrowing of the aorta), and eye anomalies. In a prospective study, 31% of infants with facial hemangiomas measuring 22 square centimeters or larger (roughly 5 cm by 4.5 cm) met the diagnostic criteria for PHACE.
Current guidelines recommend screening any infant with a large segmental hemangioma on the face or scalp, typically defined as greater than 5 cm in diameter. Screening involves imaging of the brain, heart, and major blood vessels. PHACE doesn’t change the hemangioma itself, but identifying the associated anomalies early allows doctors to manage heart, brain, or vascular problems before they cause complications.