The colloquial term “strawberry mark” refers to Infantile Hemangiomas (IH), the most common type of benign vascular tumor found in babies. These growths are caused by an abnormal proliferation of endothelial cells that line blood vessels. IH are not typically present at birth but become noticeable within the first few weeks or months of life.
What Are These “Strawberry Marks”?
Infantile Hemangiomas are classified based on their location within the skin layers. The classic “strawberry” appearance is a superficial hemangioma, characterized by a bright red, raised, and lobulated surface. This occurs because the abnormal blood vessels are clustered in the upper layer of the skin (superficial dermis).
Deep hemangiomas form in the deeper subcutaneous layer and appear as a skin-colored nodule with indistinct borders. A mixed hemangioma combines both superficial and deep components, presenting with both the bright red surface and a deeper mass. Though they can occur anywhere on the body, approximately 60% appear on the head and neck region. The majority of these lesions are localized and solitary, but some infants may develop multiple hemangiomas.
Understanding the Formation and Risk Factors
The exact biological trigger causing Infantile Hemangiomas is still under investigation, but they result from a localized error in blood vessel development (vasculogenesis or angiogenesis). The prevailing scientific theory suggests that the formation is linked to localized tissue hypoxia, or low oxygen levels, experienced during gestation or early life. Hypoxic stress is thought to upregulate factors like vascular endothelial growth factor (VEGF), which triggers the excessive proliferation of endothelial progenitor cells that form the tumor.
Another hypothesis suggests that placental tissue emboli—small fragments of placental cells that enter the fetal circulation—may lodge in the infant’s skin and trigger the abnormal growth. This is supported because hemangioma cells share certain protein markers, such as GLUT-1, with placental tissue. Several factors are consistently associated with a higher risk of development.
Risk factors include prematurity and low birth weight, with the risk increasing significantly for every 500-gram decrease in birth weight. IH are found more frequently in females, infants born from multiple gestations, and those of Caucasian ethnicity. Maternal factors, such as advanced maternal age and a history of chorionic villus sampling, are also linked to an elevated risk. These factors suggest a complex interplay of genetic and environmental influences.
The Typical Growth and Shrinkage Pattern
Infantile Hemangiomas have a distinct and predictable life cycle occurring in three phases: proliferation, plateau, and involution. The proliferation phase is marked by rapid growth, typically beginning in the first few weeks of life. It reaches 80% of its maximum size by three months of age. This initial growth spurt is driven by the rapid division of the endothelial cells, often lasting for about six to nine months, though deep hemangiomas may continue to proliferate until twelve months of age.
Following rapid growth, the lesion enters a plateau phase where its size remains stable for several months. The subsequent and longest phase is involution, where the hemangioma begins to shrink spontaneously. Involution typically starts between the child’s first and second birthday and continues slowly for several years, often until the child is five to seven years old.
During involution, the bright red color fades to a dull gray or purple, and the texture becomes softer. This process involves the replacement of the proliferative vascular tissue with fibrofatty tissue (fat and fibrous scar tissue). While most hemangiomas resolve completely, approximately 50% to 70% may leave behind residual skin changes, such as mild scarring, redundant skin, or fine, dilated blood vessels known as telangiectasias.
When to Seek Professional Guidance
While most Infantile Hemangiomas are benign and resolve without intervention, some lesions require prompt medical evaluation due to their size, location, or complications. Any hemangioma that interferes with a vital function—such as one near the eye that could obstruct vision, or one in the beard area that could compromise the airway—needs immediate specialized consultation.
Ulceration (a breakdown of the skin surface) is a common and painful complication requiring treatment to prevent infection and scarring. If an infant has five or more cutaneous hemangiomas, an abdominal ultrasound may be necessary to check for hemangiomas on internal organs, most commonly the liver.
Early intervention, ideally before four months of age, is recommended for high-risk lesions to minimize complications and disfigurement. The first-line treatment for complicated hemangiomas is oral beta-blockers, such as Propranolol, which shrink the abnormal blood vessels. For smaller, superficial lesions, topical beta-blockers like Timolol may be used.