Potassium permanganate — Condy’s crystals — is a purple crystal used, heavily diluted in water, as an antiseptic and drying soak for weeping skin conditions, infected wounds and fungal foot infections. It must always be diluted, and it is poisonous if swallowed.
What is Potassium Permanganate?
Potassium permanganate is sold as dark purple crystals or as pre-measured tablets, in pharmacies and general dealers. In South Africa it is widely known as Condy’s crystals, after the nineteenth-century chemist who popularised it.
It is a general-sale chemical rather than a registered medicine, which is why it does not appear in the South African Medicine Price Registry.
It works by oxidation. Potassium permanganate releases oxygen on contact with organic material, which destroys bacterial and fungal cell components. That same oxidising action makes it astringent — it dries weeping skin and helps a wet, oozing surface form a dry crust.
Two properties define how it must be handled:
It is only used heavily diluted. The working solution is roughly 1 in 10,000 — a very pale pink, about the colour of rosé wine. Undiluted crystals or a strong solution burn skin and mucous membranes and cause serious chemical injury.
It stains everything. Skin, nails, baths, basins, tiles, towels and clothing. Skin staining is brown and temporary; stains on surfaces and fabric are often permanent.
What is Potassium Permanganate commonly used for?
- Weeping, oozing skin conditions — infected eczema, weeping dermatitis — where the drying effect helps the surface dry and crust.
- Infected or exuding wounds and ulcers, as a soak.
- Fungal foot infections, particularly athlete’s foot with maceration between the toes.
- Tropical ulcers and infected sores.
- Blistering conditions, where soaking helps clean and dry the area.
- Foot soaks for sweaty, macerated or malodorous feet.
- Disinfecting water and equipment, in some settings.
It is a soak, not a cream. It is used for a limited number of days while the skin dries, and then stopped — continuing it dries and irritates healthy skin.
Modern wound care has moved on for most uses. Routine antiseptic soaking of clean wounds is no longer recommended; running water and appropriate dressings do better. Potassium permanganate retains a genuine place for weeping, exuding, infected skin, which is a narrower indication than it was once used for.
What it does not do: treat an infection that has spread — spreading redness, heat, swelling or fever needs antibiotics — and it is not a treatment for dry skin, ordinary eczema without weeping, or any internal condition.
How Potassium Permanganate fits into this medicine category
| Group | Examples | Use |
|---|---|---|
| Oxidising antiseptics | Potassium permanganate, hydrogen peroxide | Drying and disinfecting weeping skin |
| Modern antiseptics | Chlorhexidine, povidone-iodine | Skin disinfection; gentler on tissue |
| Topical antibiotics | Mupirocin, fusidic acid | Established bacterial skin infection |
| Antifungals | Clotrimazole, terbinafine | Fungal infection — usually more effective than a soak |
| Topical steroids | Betamethasone, hydrocortisone | Inflammation; often used after soaking dries the skin |
| Emollients | Emulsifying ointment | Dry skin — the opposite problem |
In weeping eczema, a common sequence is soak to dry, then steroid and emollient once the skin is no longer wet. See the general medicines hub, which also covers K-Fenak OTC and HP553.
What to check before using Potassium Permanganate
Dilution is the whole safety story. Get this right and it is a benign product; get it wrong and it causes chemical burns.
- Dilute to a pale pink — roughly 1 in 10,000. If the water is deep purple, it is far too strong. Dilute further until it is barely coloured.
- Dissolve the crystals fully before use. An undissolved crystal against skin causes a burn.
- Never apply crystals or concentrated solution directly to skin.
- Follow the instructions if you have pre-measured tablets, which exist precisely to avoid mixing errors.
Also:
- Soak for the time directed, usually 10 to 15 minutes, once or twice daily, for a few days only.
- Do not use it on large areas of the body, or on broken skin over a wide surface.
- Keep it out of the eyes, mouth and mucous membranes.
- Protect surfaces. Use a plastic basin or bucket rather than the bath, and expect staining.
- Wear gloves if you would rather not stain your hands and nails brown.
- Do not use it on dry skin or ordinary eczema — it will make matters worse.
- Stop when the skin is dry. Continuing dries and irritates.
- Take care with diabetes or reduced sensation, where you may not feel a burn developing. Ask a professional first.
- Ask before using it on a child, and never leave a child unattended with it.
Possible cautions and when to ask a pharmacist or doctor
Expected effects are brown staining of skin and nails, which fades over days, and a drying, tightening sensation.
Excessive concentration or prolonged use causes irritation, dryness, cracking and chemical burns.
The most serious risk is poisoning. Potassium permanganate is highly toxic if swallowed, and the crystals are attractive to children. Swallowing it causes severe burns to the mouth, throat and stomach, swelling that can block the airway, and damage to the liver and kidneys.
If anyone swallows it — particularly a child — get emergency help immediately. Take the container with you. Do not try to make them vomit, which would burn the throat a second time.
Get emergency help also for:
- Chemical burns — blistering, deep redness, or severe pain after contact with a strong solution or undissolved crystals.
- Splashes in the eye — rinse with plenty of water for at least fifteen minutes, then seek care.
- Swelling of the face, lips or tongue, or difficulty breathing.
Store it locked away from children, and never decant it into an unlabelled container or a food or drink bottle.
Contact a doctor if:
- The skin is not improving after a few days, or is worsening.
- There is spreading redness, heat, swelling, pus or fever — that needs antibiotics.
- The skin becomes cracked, painful or excessively dry on treatment.
- You have diabetes and any foot problem — those need proper assessment early rather than home soaking.
- A wound is deep, dirty, from a bite, or not healing.
- You are unsure how to dilute it. A pharmacist will tell you in seconds, and it is worth asking.
Related medicine guides
Frequently asked questions
What is potassium permanganate used for? As a heavily diluted soak for weeping or infected skin conditions, infected wounds and ulcers, and fungal foot infections. It disinfects and dries.
Are Condy’s crystals the same thing? Yes. Condy’s crystals is the common South African name for potassium permanganate.
How do I dilute it? To a pale pink — roughly 1 in 10,000. If the water looks deep purple it is far too strong. Dissolve the crystals completely before use, and ask a pharmacist if unsure.
Why does it stain my skin brown? That is the oxidation reaction. Skin staining is temporary and fades over days. Staining on baths, tiles and fabric is often permanent.
Can I use it on dry eczema? No. It is for weeping, oozing skin. On dry skin it makes things worse — that needs an emollient.
How long should I use it? A few days, until the skin is dry, then stop. Prolonged use dries and irritates healthy skin.
What if someone swallows it? Get emergency help immediately and take the container. Do not induce vomiting. It causes severe burns to the mouth, throat and stomach.
Can I use it in the bath? Better to use a plastic basin or bucket — it stains baths and tiles, often permanently.