Mild side effects
Some people get a burning or stinging feeling for a few minutes when they put mometasone on their skin. This stops happening after you've been using it for a few days.
If you get lighter or darker patches on your skin (this may be more difficult to see on brown or black skin), these are a sign of changes to the pigment in your skin. Speak to your doctor if this happens.
If your skin becomes irritated or sensitive while using mometasone cream, stop using it and tell your doctor straight away.
Speak to a doctor if your condition gets worse while you're using mometasone, or comes back within 2 weeks of stopping treatment. Do not start using mometasone again without speaking to a doctor.
Serious side effects
Serious side effects are rare. You're more likely to have a serious side effect if you use mometasone on a large area of skin for a long time.
Using mometasone for a long time can make your skin thinner or cause stretch marks. Stretch marks are likely to be permanent, but they usually fade over time.
If you're on high doses of mometasone, or you're also taking other steroid medicines or tablets for fungal infections or HIV, you may get underactive adrenal glands as a side effect. Ask your doctor if you need to carry a red steroid emergency card (for adults) or an adrenal insufficiency card if the treatment is for a child.
Call your doctor or call 111 now if:
- your skin becomes swollen, yellow fluid is weeping from your skin or your skin becomes redder (redness may be less obvious on brown or black skin) – these are signs of a new skin infection or an existing one getting worse
- you're using mometasone for psoriasis and you get raised bumps filled with pus under your skin
- you have a very upset stomach or you're being sick (vomiting), feel very tired, have very bad dizziness or fainting, muscle weakness, mood changes, loss of appetite and weight loss – these can be signs of adrenal gland problems
- you have new problems with your eyesight after starting to use mometasone
Serious allergic reaction
It happens rarely but it is possible to have a serious allergic reaction (anaphylaxis) to mometasone.
Immediate action required: Call 999 now if:
- your lips, mouth, throat or tongue suddenly become swollen
- you're breathing very fast or struggling to breathe (you may become very wheezy or feel like you're choking or gasping for air)
- your throat feels tight or you're struggling to swallow
- your skin, tongue or lips turn blue, grey or pale (if you have black or brown skin, this may be easier to see on the palms of your hands or soles of your feet)
- you suddenly become very confused, drowsy or dizzy
- someone faints and cannot be woken up
- a child is limp, floppy or not responding like they normally do (their head may fall to the side, backwards or forwards, or they may find it difficult to lift their head or focus on your face)
You or the person who's unwell may also have a rash that's swollen, raised, itchy, blistered or peeling.
These can be signs of a serious allergic reaction and may need immediate treatment in hospital.
Long-term side effects
Using mometasone skin treatments for a long time without stopping can mean some of the medicine gets into your blood.
Sometimes, there's a very small chance that this can cause serious side effects, such as adrenal gland problems, high blood sugar (hyperglycaemia), or problems with your eyesight.
If you've been using mometasone for a long time, your doctor may tell you to gradually reduce the amount you use before stopping completely.
Sometimes, stopping after a long time can cause a skin reaction within a few days or weeks of stopping treatment (topical steroid withdrawal reaction). You may have a burning feeling and redness, although this may be more difficult to see on brown or black skin. If this happens, ask your doctor for advice.
Children and teenagers
In very rare cases, using mometasone for a long time can slow down the normal growth of children and teenagers.
Your child's doctor will monitor their height and weight carefully for as long as they're using this medicine. This will help them to notice if your child's growth is being affected and change their treatment if needed.
Even if your child's growth slows down, it does not seem to have much effect on their overall adult height.
Talk to your doctor if you're worried. They'll be able to explain the benefits and risks of your child using mometasone.
Other side effects
These are not all the side effects of mometasone. For a full list see the leaflet inside your medicines packet.
You can report any suspected side effect using the Yellow Card safety scheme.