A blue-grey birthmark around my baby's eye: the check it needs

Key takeaways

A slate, blue or grey patch on one side of a baby's forehead, temple, eyelid or cheek is most often a naevus of Ota, and it is more common in Asian children than in white children.
The same pigment cells are often present inside the eye as well, where they cause no symptoms at all and cannot be seen by looking at your child.
The eye risk is glaucoma, because pigment can collect in the part of the eye that drains fluid away, so eye pressure needs measuring rather than watching.
Laser can lighten the skin. It does not reach the pigment inside the eye, so treating the birthmark never replaces the eye appointment.
One examination is a baseline, not an all-clear. If the eye is involved, checks continue once a year for life.

Parents bring me birthmarks fairly often, and almost always they have already been to someone about the skin. What they have usually not been told is the part that brings them to me: a slate or blue-grey patch around one eye can come with pigment inside that eye as well, and pigment inside an eye is invisible in a mirror.

So this article is not really about the mark on your baby's face. It is about one appointment that goes alongside it, and that appointment is the one families skip.

What is this blue-grey mark around my baby's eye?

Most often it is a naevus of Ota, a birthmark made of pigment cells sitting deeper in the skin than the cells that make an ordinary freckle. Because they sit deeper, the colour reads as slate, blue or grey rather than brown, so it can look more like a bruise or a shadow than a birthmark.

Two things usually give it away. It is nearly always on one side of the face only. And it does not stop where a shadow would: it spreads across some combination of the forehead, the temple, the upper or lower lid, and the cheek, following the territory of one nerve rather than the shape of a hollow.

About half of these birthmarks are there from birth. The rest tend to appear later, often around puberty. It is more common in Asian children than in white children, which matters here: in Japan, where it has been counted properly, somewhere between two and six people in every thousand have one. It also appears more often in girls than in boys. If you have been told this is very rare, that figure was probably not about children who look like yours.

Will it fade as she grows?

No, and I would rather you heard that from me than waited two years to find out. This is not the mottled newborn colouring that settles in the first months, and it is not the flat bluish patch low on the back that many Asian babies have and grow out of. A naevus of Ota is a fixed feature of the skin. It can darken a little with time or with hormonal change, and it does not lighten on its own.

That sounds like bad news and it is really just information. Nothing about the skin needs to be decided in your baby's first year, and nothing about the skin is urgent. The part that has a timetable is the eye.

The skin is the visible half. It is not the half with a clock on it.

Why does a birthmark on the skin need an eye examination?

Because the same pigment cells often turn up in the eye itself, and there is no way to know from the face whether they have. When they do, they sit in the white of the eye and the thin layer over it, sometimes in the iris, making the two eyes look different colours, and sometimes in the deeper layer behind the retina. In one published series of Asian patients, more than half of the eyes examined carried this pigment.

Pigment inside an eye causes no symptoms at all. Your baby cannot feel it, will not rub at it, and will see perfectly well with it. There is nothing for you to notice, which is exactly why it has to be looked for rather than waited for. The examination itself is the only way to answer the question, and either answer is useful. Some children have skin pigmentation and a completely clear eye.

This is also the reason I ask for a baseline while a child is small. A first set of measurements taken at two makes every comparison at twelve and at thirty mean something. Without it, someone in twenty years is looking at one reading with nothing to compare it against.

What is the eye risk, in plain terms?

Glaucoma, and the risk is higher than average rather than high. The eye makes fluid continuously and drains it through a fine mesh in the angle where the iris meets the cornea. Pigment cells can collect in that mesh. Drainage becomes less efficient, pressure rises, and pressure that stays raised damages the optic nerve over years. That damage is painless and silent, which is the whole reason we measure rather than wait for a complaint.

The published numbers move around depending on how strictly glaucoma is defined and who is counted. In that same Asian series, frank glaucoma was found in about one eye in a hundred, and raised pressure without glaucoma in about three in a hundred. Both were commoner in the eyes that carried pigment than in the children whose pigmentation was skin only. Reviews that look specifically at people whose eye is involved report higher figures again.

Here is the part I want you to take away, because it is genuinely reassuring. In that series, among the children aged ten and under, none had glaucoma. The point of your baby's first appointment is not to find something. It is to establish whether the eye is involved and to write down a starting point.

What happens at the appointment, and will it upset her?

Less than you are imagining. I look at the surface of the eye with a bright light and a magnifier, which for a baby usually means a few seconds on your lap. I measure the pressure, and in a small child that is done with an instrument held near the eye rather than anything pressed onto it. Then I use drops to widen the pupil so I can see the layers at the back.

The drops sting for a few seconds and then stop. Pupils stay large and near vision stays blurry for several hours, so bring a hat for the walk out. If you want the full picture of what an examination of a small child actually involves, I have set it out in how we test eyes before a child can read, and none of it requires your baby to cooperate or answer anything.

In older children I add a look at the drainage angle itself using a special contact lens, which needs a child who can sit still, so it waits until they can. If the eye is involved and a child is very young and very anxious, an examination under anaesthetic is occasionally the sensible route, and that is a decision made with you, not announced at you.

Can it be removed, and would that sort out the eye too?

Laser can lighten the skin. It does not reach the pigment inside the eye, and it is not designed to. This is the single sentence I would like every family with this birthmark to carry away, because a treated face and an unexamined eye is a combination I have met more than once.

The skin treatments used for this are pigment lasers, the Q-switched and picosecond kind. They work by breaking pigment into fragments the body clears, and the published experience is that several sessions are needed and that the colour can return after clearance, occasionally darker than it started. Whether to treat at all, when, and with which device is a decision for a doctor who does that work daily. It is not mine, and I do not pretend otherwise.

What I do say to every family is the same thing. The pigment inside the eye is behind the cornea and the white of the eye, in different tissue entirely. Clearing the visible patch changes nothing about the drainage angle, nothing about the pressure, and nothing about what is happening at the back of the eye. If the skin is going to be treated, book the eye appointment in the same week, and keep it every year afterwards whatever the skin ends up looking like.

How often does she need checking, and for how long?

Once a year, and for life if the eye is involved. That sentence surprises parents more than anything else here, so let me be plain about why. The pressure can rise at any age rather than only in childhood, so there is no point at which a normal result becomes a permanent all-clear. One good examination is a baseline, not a discharge.

In practice that means an appointment now, a rhythm of yearly visits through childhood, and a handover into adult ophthalmology when she outgrows me. The adult half of this, including what the monitoring looks like across a lifetime and what the published melanoma figures do and do not mean for an Asian patient, is set out by my colleague Dr Catherine Chow, a consultant oculoplastic surgeon, in her piece on why that birthmark needs an eye doctor and not only a laser. If you are an adult reading this about your own face, hers is the more useful article. The skin half, meaning how the pigment lasers actually compare and what a course of them can realistically change, is set out by Dr Ong Jin Khang at The Retreat Clinic in what a pigment laser can and cannot reach. The line all three of us hold to is the same one: laser lightens the skin, it does not reach the pigment inside the eye, and the yearly eye pressure check continues for life whatever is done to the skin.

One last thing, because I know what a parent does after reading something like this. You will not be able to see this by looking, and you are not expected to. Nothing about pigment inside an eye shows up in a photograph, and it is not the sort of thing that changes between Tuesday and Thursday. Your job is a diary entry once a year, not a watch kept at home. The first eye check is where it starts, and if you are also wondering what a baby can actually see at each stage, how babies learn to see covers that separately.

Bring the appointment forward if…

Your child has this birthmark and has never had an eye examination, at any age.
The white of the eye on the same side has a slate or grey patch in it.
The two eyes look like different colours, or one pupil looks larger than the other.
One eye looks bigger than the other, or your child is bothered by bright light on one side.
You are booking a first laser session for the skin and no eye appointment is in the diary.

Common questions

My baby has a blue-grey mark around one eye. What is it?

Most often a naevus of Ota, a birthmark made of pigment cells sitting deeper in the skin than the ones that make a freckle, which is why it looks slate or blue rather than brown. It is nearly always on one side only, and it spreads across the forehead, temple, eyelid or cheek rather than stopping at a single spot. About half are present at birth.

Is a birthmark near the eye dangerous?

The birthmark itself is not. What matters is that the same pigment is often inside the eye as well, and pigment can collect in the part of the eye that drains fluid, which raises the chance of glaucoma over a lifetime. That is a reason for a yearly appointment, not a reason to worry between appointments.

Will the birthmark fade as she grows?

No. This is not the mottled newborn colouring that settles in the first months, and it is not the flat bluish patch low on the back that many Asian babies grow out of. A naevus of Ota is a fixed feature of the skin. It can darken slightly over time, and it does not lighten on its own.

Does the birthmark mean something is wrong inside the eye?

Not necessarily, and that is exactly why the examination is worth doing. Some children have pigmentation in the skin only and a completely clear eye. Others have pigment in the white of the eye, the iris or the deeper layers. You cannot tell which from the face, and your child will have no symptoms either way.

Can it be removed with laser, and does that fix the eye too?

Laser can lighten the skin, and several sessions are usually needed. It does not reach the pigment inside the eye and is not designed to, so it changes nothing about the eye pressure or the drainage angle. Whether to treat the skin at all is a decision for a doctor who does that work; the eye appointment happens either way.

How often will my child need her eyes checked?

Once a year if the eye is involved, and that continues into adult life rather than stopping at a certain age. Eye pressure can rise at any age, so a normal examination is a starting point rather than a discharge. Your child will be handed over to adult eye services when she outgrows a paediatric clinic.

Will the examination upset my baby?

Usually far less than parents expect. Looking at the surface of the eye takes seconds on your lap, and pressure in a small child is measured with an instrument held near the eye rather than pressed onto it. Drops to widen the pupil sting briefly, then stop, and leave near vision blurry for a few hours.

Nobody mentioned the eyes when we saw someone about the skin. Have we left it too late?

No, and this comes up often enough that it is worth saying plainly: there is no age at which this examination stops being worth doing. Whether your child is two or twelve, the visit still establishes whether the eye is involved and still gives every later check something to compare against. Book it, and no one will think you should have come sooner.

References

DermNet NZ · Naevi of Ota, Ito and Hori · dermnetnz.org
StatPearls (NCBI Bookshelf) · Nevus of Ota and Ito · www.ncbi.nlm.nih.gov
Prevalence of glaucoma and ocular manifestations in naevus of Ota · pmc.ncbi.nlm.nih.gov
Ophthalmological perspectives in oculodermal melanocytosis · pmc.ncbi.nlm.nih.gov

By Dr Chan Li Yen. General information only. It does not replace a consultation. If you are worried about your child's eyes or vision, please see an eye doctor.