Infantile hemangiomas, commonly known as strawberry birthmarks, are a frequent occurrence in infants. These benign growths typically appear within the first few weeks of life and are characterized by their distinctive reddish appearance. Although their presence can sometimes cause concern for new parents, most strawberry birthmarks are harmless and resolve naturally without requiring medical intervention. They represent a specific type of vascular anomaly that follows a predictable course of development and eventual fading.
Understanding Strawberry Birthmarks
Strawberry birthmarks resemble the surface of a ripe strawberry. They are typically bright red, raised, and can have a bumpy or rubbery texture. These marks are a type of benign vascular tumor, composed of an abnormal collection of blood vessels.
While many appear on the head and neck, they can develop anywhere on the body, including the face, trunk, or limbs. They are quite common, affecting approximately 4% to 10% of infants. They are observed more frequently in girls, premature babies, infants with low birth weight, and those of Caucasian ethnicity.
The Science Behind Their Formation
Strawberry birthmarks develop due to an overgrowth of endothelial cells, which are the specialized cells lining blood vessels. This overgrowth leads to the visible mark. The exact cause of this rapid growth is not fully understood, but current research points to a combination of factors.
One prominent theory suggests a connection to placental cells, implying that some hemangiomas may arise from displaced placental tissue during gestation. Genetic predispositions are also under investigation, with studies indicating that genetic factors and specific signaling pathways may contribute to their formation and rapid growth. This suggests an altered regulation of blood vessel development.
Their Typical Progression
Infantile hemangiomas follow a characteristic three-phase natural history. Initially, there is a rapid growth phase, known as the proliferative phase, which typically begins a few weeks after birth. During this period, the birthmark grows quickly, often reaching about 80% of its maximum size by three months of age and peaking in growth around five months.
Following this rapid expansion, the birthmark enters a plateau phase, where its size remains stable for several months. The final stage is the involution phase, where the hemangioma begins to shrink and fade. This process can be slow, with some fading by the first birthday, about 50% resolving by age five, and 70% by age seven. Most hemangiomas will have completed their involution by nine to ten years of age, with the color changing from bright red to purple or gray as it regresses.
When Medical Intervention is Needed
While most strawberry birthmarks resolve on their own without complications, certain situations may necessitate medical evaluation or intervention. Approximately 10% to 25% of hemangiomas can develop complications such as ulceration, causing pain and potential bleeding. These sores are problematic in moist areas like the diaper region or lips.
Intervention is also considered if the hemangioma interferes with vital functions, such as vision, breathing, or feeding. Large or prominently located hemangiomas, especially on the face, can also have a psychological impact on the child and parents. In such cases, a specialist consultation is recommended, ideally by one month of age for high-risk lesions.
Monitoring is a common approach for uncomplicated hemangiomas. For those requiring treatment, oral propranolol is often the first-line medication, which constricts blood vessels and limits cell growth, leading to rapid improvement. Other options include topical timolol for superficial lesions, or corticosteroids. Laser therapy may be used for ulcerated hemangiomas, to address residual redness or fine blood vessels. Surgical removal might be considered for unhealed ulcers, functional impairment, or residual skin and fatty tissue after regression.