A purple antiseptic soak for weeping skin
Potassium permanganate
A purple antiseptic and drying (astringent) solution used, well diluted, as a soak for weeping or infected skin.
What is Potassium permanganate?
Potassium permanganate is a purple antiseptic and astringent used as a diluted soak or bath for skin that is weeping, blistered or infected, such as in some types of eczema or leg ulcers. It helps dry up oozing and reduce surface infection. The most important safety point is that it must always be well diluted before use, because a concentrated solution can burn the skin. It stains the skin, nails, hair and bath or container a brown colour, and it is harmful if swallowed, so it must be kept away from children and never taken by mouth.
Education and reference only. This is a plain-language guide to Potassium permanganate — it deliberately contains no doses. Doses depend on the person, the brand and the reason for treatment, and belong with your prescriber. Always check the BNF, the product labelling (SmPC) and follow medical advice.
What it is
Potassium permanganate is a long-established antiseptic that also has a drying, astringent effect on the skin. It comes as crystals or tablets that are dissolved in water to make a pink-to-purple solution, which is then used as a soak, compress or bath for skin problems that are wet, weeping, blistered or infected, such as some flares of eczema or leg ulcers. It is used on the outside of the body only. Because the concentrated form is strong, it always has to be diluted carefully before it touches the skin.
How it works
Potassium permanganate works as an antiseptic, helping to reduce the bacteria on the surface of the skin, and as an astringent, which dries out weeping or oozing areas and helps the skin to settle. Soaking the affected area in the diluted solution lets it act across the whole surface, which is useful for widespread or hard-to-reach areas. Because its strength matters, it is the dilution that makes it safe and effective: too weak does little, while too strong can damage the skin, so it is always made up to the right pale colour before use.
Company & origin
Originated / developed by: Generic (long-established).
A long-established purple antiseptic used in the UK as a diluted soak or bath for weeping, blistered or infected skin conditions.
Practical use
How to take Potassium permanganate
General, dose-free guidance — always follow your prescriber's and the leaflet's specific instructions.
- Always dilute it fully in plenty of water to a pale pink colour before using it on the skin.
- Make sure all the crystals or tablet have dissolved, as undissolved pieces can burn the skin.
- Use it only on the outside of the body, as a soak, compress or bath, for as long as advised.
- Expect brown staining of skin, nails and the bath or bowl, and protect surfaces and towels.
- Keep it well away from children and never swallow it, as it is harmful if taken by mouth.
Weighing it up
Advantages & disadvantages of Potassium permanganate
Advantages
- A simple, long-established way to dry up weeping skin and reduce surface infection.
- Useful for soaking widespread or awkward areas such as legs or feet.
- Inexpensive and effective when made up to the correct dilution.
Disadvantages
- Must be carefully diluted, as the concentrated solution can burn the skin.
- Stains the skin, nails, hair and bath or container brown.
- Harmful if swallowed and not suitable for use inside the body.
Practical use
Good to know
The most important thing to understand is that potassium permanganate must always be well diluted before it touches the skin: in its concentrated form it can burn, so the crystals or tablets are dissolved fully in plenty of water to make a pale pink solution, with no undissolved bits left that could harm the skin. It stains things brown, including the skin, nails, hair, towels and the bath or bowl, which is harmless to the skin but worth knowing and protecting against. It is for external use only and is harmful, even dangerous, if swallowed, so it must be kept well away from children and never taken by mouth. It is usually used for short courses on weeping skin, and the skin is rinsed and dried gently afterwards.
Who should not take it / use with caution
- It must not be swallowed or used inside the body, as it is harmful if taken by mouth.
- People who have had a reaction to it on the skin should not use it.
- It is kept well away from children because of the risk of accidental swallowing and skin burns.
Monitoring
- Checking that the skin condition is improving and the weeping is settling.
- Watching for signs of skin irritation or burning from too strong a solution.
- Reviewing how long the soaks are needed, as they are usually for short courses.
Side effects
- Brown staining of the skin, nails, hair and surroundings, which is harmless but can be marked.
- Skin irritation, dryness or, with too strong a solution, burns.
- If swallowed, serious harm to the mouth, throat and gut, needing urgent medical help.
Key interactions
- It has few medicine interactions, as it works on the surface of the skin.
- It should not be mixed with other chemicals or strong substances when making up the solution.
- Tell your prescriber about other creams or treatments you use on the same skin.
Available as: Crystals or tablets dissolved in water to make a diluted solution for soaks, compresses or baths; for external use only.
Answers
Potassium permanganate: frequently asked questions
What is potassium permanganate used for?
It is a purple antiseptic and drying solution used, well diluted, as a soak or bath for skin that is weeping, blistered or infected, such as some flares of eczema or leg ulcers.
Why must it be diluted?
In its concentrated form it can burn the skin, so it is always dissolved fully in plenty of water to a pale pink colour before use, with no undissolved bits left.
Why does it stain everything brown?
Potassium permanganate naturally stains the skin, nails, hair and the bath or bowl a brown colour; this is harmless to the skin but it helps to protect surfaces and towels.
Is it safe to swallow?
No. It is for external use only and is harmful, even dangerous, if swallowed, so it must be kept well away from children and never taken by mouth.
How long should I use it?
It is usually used for short courses on weeping skin; follow the advice you are given and rinse and dry the skin gently afterwards.
Authoritative sources
- BNF
- NICE CKS
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