Infantile hemangiomas, commonly known as strawberry hemangiomas, are the most frequent benign vascular tumors found in infancy. These growths result from an abnormal proliferation of endothelial cells and typically appear within the first few weeks of life. They are seen in up to 10% of infants and affect female infants more often than males. These vascular lesions have a predictable life cycle: they grow for a period and then ultimately shrink and fade away on their own without the need for intervention in the majority of cases.
What Exactly is a Strawberry Hemangioma
A strawberry hemangioma is a type of superficial infantile hemangioma that forms a raised, bright red, and often rubbery mass on the skin’s surface. They get their common name from this distinct color and texture, which resembles a strawberry. Hemangiomas are noncancerous and do not pose a threat of malignancy to the child. They are most frequently found on the head and neck, accounting for approximately 60% of cases, but they can occur anywhere on the body.
The underlying cause is a localized cluster of blood vessels that have grown excessively. They are generally absent at birth or present only as a faint discoloration, but they become clinically apparent within the first month of life. If the hemangioma is deeper under the skin, it may appear as a bluish lump, sometimes referred to as a deep or cavernous hemangioma. The presence of these growths has been associated with factors like low birth weight, premature birth, and being female.
The Natural Life Cycle and Involution
The natural history of an infantile hemangioma follows a distinct, multi-phase evolution: the proliferative phase and the involution phase. The proliferative phase, the initial period of rapid growth, begins shortly after birth and is marked by a rapid increase in the size of the lesion. During this phase, the endothelial cells are actively multiplying, which causes the hemangioma to become larger, thicker, and more noticeable.
The growth rate is fastest during the first few months of life, with most of the hemangioma’s eventual size achieved by around five to six months of age. After this rapid expansion, the lesion enters the involution phase, the biological process of spontaneous regression. Involution involves the vascular tissue being slowly replaced by fibrofatty tissue, causing the hemangioma to soften and the bright red color to fade to a duller gray or white.
Typical Timeline for Disappearance
The proliferative phase slows down significantly and stops by the time the infant is nine to twelve months old. Once the hemangioma enters the involution phase, the timeline for complete disappearance is variable but predictable. Approximately 50% of infantile hemangiomas will have completely resolved by the time a child reaches five years old.
The rate of resolution continues, as about 70% of these lesions are resolved by age seven. Near-complete resolution, where the hemangioma is gone or very difficult to see, is expected by a child’s tenth birthday. While the hemangioma may disappear, some children are left with residual signs, such as slightly loose or stretched skin, fine surface blood vessels, or a subtle change in skin texture.
When Medical Intervention is Necessary
While the majority of strawberry hemangiomas regress without treatment, medical intervention is necessary for a small percentage of cases where the lesion poses a functional risk or is associated with complications. Treatment may be required if the hemangioma threatens a vital function, such as obstructing the line of vision, interfering with feeding, or causing breathing difficulties in the airway. Ulceration, the formation of a painful, open sore on the hemangioma, is the most common complication and necessitates prompt treatment.
The primary medical treatment for problematic infantile hemangiomas is the use of beta-blockers, specifically oral propranolol, which is the first-line therapy. Propranolol works by causing the blood vessels to constrict and signaling the endothelial cells to die off, which accelerates the involution phase. Topical beta-blockers, like timolol, may be used for smaller, superficial lesions that do not pose a high risk. Surgery or laser treatment is reserved for lesions that fail to respond to medication, or to remove any residual excess skin or tissue that remains after the hemangioma has fully involuted.