I’ll confess that I knew very little about haemangiomas before our little boy developed one. Infantile haemangiomas, more colloquially known as strawberry naevi if they appear on the skin’s surface, are a type birthmark that, although often not present at birth, develop in the first few weeks of a baby’s life. They normally start as a small bruise-like patch and can swell into a red blob, which gives rise to the name ‘strawberry’, and often reach their maximum size within the first year. They are benign and are rarely treated, instead being left to recede and eventually fade as the child gets past 3-4 years of age.
It’s interesting that they’re so common – approximately 10% of Caucasian babies have them (they’re less common in other ethnicities) – yet no one really knows what causes them. They are known to arise as a result of overgrowth of the cells surrounding blood vessels, and there are theories that this is due to high levels of oestrogen in the womb or to a tiny piece of placenta that lodges itself to the developing baby’s skin, but there is very little hard evidence for a cause. All we know for sure is the observed prevalence – they’re more common in girls by 3:1, and low birth weight or premature babies are more likely to develop one.
They can certainly be psychologically distressing for children, especially when they develop prominently on the face and take a long time to recede (see image search). They can also physically affect a child if it grows on or near their eye, nose or mouth – the majority of haemangiomas grow on the face or neck – and can consequently impair sight, breathing and eating. We are lucky in the sense that our boy’s growth is on the top of his head, away from any organs, and we hope that hair will grow to cover it.
Other parents whose child had a strawberry naevus are very keen to come up and point it out. Usually it’s for the comforting reassurance that their child’s growth faded by the time they were five years old. What is less welcome is people whose first offhand question is “what’s that thing on his head?” or “did you drop him?”.
It’s a common benign growth and, no, we didn’t.
Our little one’s started, as seems most common, as a red patch at around 4 weeks old and has grown over the next 3 months to around 2.5 cm across and protuding around 1 cm. After assuring ourselves that it was benign and not the result of an injury, we decided to take him to the dermatologist to double-check and get some more information from a health professional.
The dermatologist asserted that “10% are gone by 1 year and all are gone by age 10”. That was a relief to hear. But I was curious as to whether 100% of haemangiomas really are gone by the 10 years old and so did what any right-minded person would do: google.
This brought me across some interesting findings, even ignoring the usual sources of unsubstantiated claims and focussing on those with a little more validity. On average they disappear at a rate of 10% per year – 70% are gone by the age of 7, 80 % by age 8, and so on. However, it seems that after 90% have receded by the age of 9, the graph plateaus, leaving 10% of haemangiomas still present by age 10. That made me wonder whether the dermatologist simply extrapolated this trend to 100% by age 10.
According to the Office of National Statistics there were 807,257 registered births in the UK in 2010. Using the estimate of 5% prevalence, that means we can expect over 40,000 haemangiomas in that year. More than 36,000 of these growths will probably disappear (90%), which leaves approximately 4,000 of the 2010 babies with marks that will not completely disappear. At this stage, laser treatment or steroids are often used to reduce the size of growth or surgical removal may be needed.
These are clearly not trivial interventions (risk of blood loss, permanent scarring, etc.) and it would have, in my view, been incumbent on the dermatologist advising us that there was a chance, albeit slim, that we would be in this position. Instead, we received a casual assurance and were sent on our way.