A traditional psoriasis and eczema treatment
Coal tar
A traditional tar-based treatment that reduces scaling and itching in psoriasis and some eczema.
What is Coal tar?
Coal tar is a traditional treatment applied to the skin or scalp for psoriasis and some types of eczema. It reduces scaling, itching and inflammation. It has a strong smell and can stain skin, hair and fabrics, can make the skin more sensitive to sunlight, and should not be used on broken or weeping skin.
Education and reference only. This is a plain-language guide to Coal tar — 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
Coal tar is a long-used treatment for psoriasis and some types of eczema, applied to the skin or scalp. It comes as ointments, creams, lotions, bath additives and medicated shampoos. In the UK it is available both on prescription and from pharmacies, and is often used for stable plaque psoriasis and scalp conditions. It is usually applied regularly, with shampoos left on for a short time before rinsing.
How it works
Coal tar slows down the rapid growth of skin cells that causes the thick, scaly patches of psoriasis, and it has anti-inflammatory and anti-itch effects. It helps to lift and soften scale, making plaques smoother and less flaky. In some types of eczema it can also reduce itching and inflammation over time.
Company & origin
Originated / developed by: A traditional skin treatment.
A long-established topical treatment used in the UK for psoriasis and some forms of eczema.
Practical use
How to take Coal tar
General, dose-free guidance — always follow your prescriber's and the leaflet's specific instructions.
- Apply tar ointments or creams in a thin layer to the affected areas, following the direction of hair growth where relevant.
- For medicated shampoos, massage into the scalp, leave on for a short time as directed, then rinse out thoroughly.
- Avoid broken, cracked or weeping skin, and keep it away from your eyes, lips and genital area.
- Use sun protection and avoid sunlamps, as tar can make your skin more sensitive to sunlight; use old towels and clothing to limit staining.
- If you forget an application or wash, simply carry on with the next one as planned rather than doubling up.
Weighing it up
Advantages & disadvantages of Coal tar
Advantages
- A long-established, steroid-free option that reduces scaling and itching.
- Available in many forms, including shampoos and bath additives for the scalp and large areas.
- Can be used over longer periods for stable plaque psoriasis.
Disadvantages
- Has a strong smell and stains skin, hair, fabrics and surfaces.
- Can make the skin more sensitive to sunlight.
- Can be messy and time-consuming, and may irritate sensitive or broken skin.
Practical use
Good to know
Coal tar has a distinctive strong smell and can stain skin, hair, fabrics, baths and bedding, so use older towels and clothing and protect surfaces. It can make your skin more sensitive to sunlight, so use sun protection and avoid sunlamps during treatment. Do not apply it to broken, cracked, weeping or infected skin, as this can sting and worsen irritation. Some preparations are stronger and messier than others, so your prescriber or pharmacist can help you choose one that suits the area and how much time you have. As with other psoriasis treatments, it usually takes a few weeks of regular use to see the benefit.
Who should not take it / use with caution
- It should not be applied to broken, cracked, weeping or infected skin.
- People with widespread pustular psoriasis should avoid it unless a specialist advises otherwise.
- Anyone who has reacted badly to coal tar preparations should not use them.
Monitoring
- No routine blood tests are needed; treatment is judged by how the skin and scaling respond.
- Your prescriber reviews progress over several weeks and may switch preparation if it does not suit you.
- Report any marked irritation, worsening rash or signs of infection in treated areas.
Side effects
- Skin irritation, redness, stinging or a rash, especially on sensitive areas.
- Staining of skin, hair, nails, clothing and bedding, plus a strong smell.
- Increased sensitivity to sunlight, and occasionally inflammation around hair follicles.
Key interactions
- Avoid combining it with other strong or irritant skin products on the same area unless advised.
- Take extra care with treatments or activities that increase sun exposure, as tar adds to sun sensitivity.
- Tell your pharmacist about other scalp or skin products you use.
Available as: Ointments, creams, lotions, bath additives and medicated shampoos.
Answers
Coal tar: frequently asked questions
Why does it smell and stain so much?
Coal tar naturally has a strong smell and can stain skin, hair, fabrics and surfaces, so use older towels and clothing and protect baths and bedding.
Can I use it on broken skin?
No, avoid broken, cracked, weeping or infected skin, as tar can sting badly and make irritation worse there.
Does it make me sensitive to the sun?
Yes, it can make your skin more sensitive to sunlight, so use sun protection and avoid sunlamps during treatment.
Is it a steroid?
No, coal tar is a traditional, steroid-free treatment that works by slowing skin-cell growth and reducing scaling and itching.
How long until it helps?
It usually takes a few weeks of regular use before scaling and itching clearly improve, so keep using it as directed.
The wider class
About Topical psoriasis/eczema treatments
Coal tar belongs to the topical psoriasis/eczema treatments class. For how the class as a whole works, its shared safety principles and monitoring, see the full guide.
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Authoritative sources
- BNF
- NICE CKS
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