Chloasma Gravidarum: Four Facts Worth Knowing

You catch yourself in the mirror in daylight and there are patches across your cheeks that were not there in January.

Chloasma gravidarum is the medical name. Melasma is the one you will hear more often, and mask of pregnancy is what everyone actually calls it. Four things are worth knowing.

1. Your hormones are doing it

Oestrogen and progesterone stimulate melanocytes, the cells that make pigment.

The same process is darkening other places at the same time: the line down your belly, your nipples, your underarms, your inner thighs. One mechanism, several changes, which is why they all show up together.

Genetics decide who gets it. More common on deeper skin tones, and it tends to run in families.

2. Sun makes it worse, and that part is yours

UV switches on the same melanocytes your hormones already woke up. The patches deepen through sunny weeks and settle through cloudy ones.

Which means sun protection does more for chloasma than any active ingredient you could buy.

• Sunscreen every morning, cloudy days included
• Reapply every two hours if you are out
• A wide-brimmed hat, which outperforms most creams
• Stay out of it between 10am and 4pm where you can

Most UV comes straight through cloud, and here the intensity stays high all year.

3. It is not harming anything

Chloasma causes no medical problem for you or your baby. It does not itch, flake or hurt, and if what you have does any of those, it is something else.

The reason to do anything about it is that you do not like how it looks. That is a perfectly good reason, and it is a different one from health.

One thing worth checking: chloasma is flat and usually symmetrical. A patch that is raised, one-sided, or changing shape is a different question and deserves a doctor's eye.

4. It usually fades after the birth

For most Mamas the patches lift over the months afterwards as hormones settle. Six months to a year is common.

It often comes back in the next pregnancy, and it can hang around where there has been a lot of sun. Persistent chloasma is treatable, usually starting once breastfeeding is done and the full range of options opens up.

Dermatologists talk about melasma as managed rather than cured. It responds well and returns readily without sun protection, which is worth knowing before you start a course of anything.

What you can use now

The usual actives, hydroquinone, retinoids and high-dose acids, are all set aside during pregnancy.

What is left still works:

Sunscreen. The one that matters.

Vitamin C and niacinamide, both considered safe and both useful for tone.

A gentle hand. Irritated skin pigments more, so scrubs and anything that leaves your face red will set you back.

Daily Protection Face Moisturizer SPF 20 PA++ is moisturiser and mineral sunscreen in one step, which is one fewer thing to remember.

Gentle Face Wash does the cleansing on a mild base.

SPF 20 suits everyday indoor life. If you are going to be out for hours, go higher.

Do not

Buy unregistered whitening creams. Products sold online without registration still routinely turn out to contain mercury, which crosses the placenta. This is a real hazard, unlike most of what gets called dangerous.

Put neat lemon juice on your face. It contains psoralens, which react with sunlight and leave patches darker for months. A popular remedy that makes things reliably worse.

Scrub or peel skin that is already reacting.

Compare your face to anyone else's pregnancy. Chloasma affects a large share of pregnant Mamas and says nothing about how you have looked after your skin.

When to see a dermatologist

• Patches still there several months after the birth
• Pigmentation spreading despite daily sun protection
• Any patch that is one-sided, raised, or changing shape
• Genuine doubt about whether this is chloasma at all