From dandruff to psoriasis, the most common causes and best treatment options for an itchy scalp.
Can’t stop itching your head? An itchy scalp is an incredibly common (and often very frustrating) condition, but it’s not usually the sign of anything more serious. However, some itchy scalp signs can indicate that something needs treating and madly itching the area can make things worse.
Dr Roger Henderson looks at the most common causes and best treatment options for an itchy scalp and what you can do to prevent the dreaded itch from returning:
What is an itchy scalp?
An itchy scalp – also called scalp pruritis – is a common problem. Although rarely due to a serious condition, it can cause significant discomfort thanks to frequent scratching and there may also be signs such as flaking skin or sores on the scalp.
Itchy scalp symptoms
Unsurprisingly, the main cause of an itchy scalp is the itching, but the scalp can also feel painful or tingling. Scratching may cause a temporary easing of the itch but it then recurs. Other associated problems may include hair loss, dry skin, infected sores, scalp swelling and scales on the scalp.
Itchy scalp causes and treatments
There are five typical causes of an itchy scalp, listed below. Other possible but less common itchy scalp causes include diabetes, allergies, anxiety, contact dermatitis (due to the scalp reacting to something it has been in contact with), excessive heat due to hair styling and alopecia. The best itchy scalp treatment depends on the cause:
Dandruff, also known as pityriasis capitis, is the most common cause of a dry, flaky and often itchy scalp. Most people are familiar with the appearance of tiny white flakes of dead skin on the shoulders of people that suffer from it, and it can affect up to half of all adults at some time.
Dandruff is not caused by poor hygiene, although it may be more obvious if you do not wash your hair regularly. Dandruff is due to dead skin cells being shed more rapidly than usual, and left untreated it can cause embarrassment and self-esteem problems. Using certain hair products excessively can sometimes lead to dandruff occurring and stress and cold weather may also make dandruff worse.
✔️ Dandruff treatment
Dandruff is best treated with anti-dandruff shampoos that can be bought from pharmacies or supermarkets. Look for a shampoo containing one of these ingredients:
- Zinc pyrithione
- Salicylic acid
- Selenium sulphide (or selenium sulfide)
- Coal tar
Use the shampoo for a month to see if your dandruff improves as you might need to try more than one type to find one that works for you. If you still have symptoms after using anti-dandruff shampoo for a month or if your scalp remains very itchy or reddened, then ask your GP for advice.
2. Seborrhoeic dermatitis
Seborrhoeic dermatitis affects around 3- 4 per cent of the population, and can start at any time after puberty. It is slightly more common in men and also runs in families. Babies can also get a short lived type of seborrhoeic dermatitis in the scalp known as cradle cap which usually clears after a few months.
Seborrhoeic dermatitis is thought to be triggered by an overgrowth of the Malassezia yeast that lives on the skin, or possibly by an overreaction by the skin’s immune system to this yeast. Seborrhoeic dermatitis is not usually linked to any underlying illness, but may be triggered by tiredness and stress. It is more common in cold weather, and it is not related to diet.
The symptoms of seborrhoeic dermatitis seem to vary from person to person. Affected areas can be itchy, sore and sensitive and flaking skin can be bothersome and embarrassing, while some people are not troubled by it.
✔️ Seborrhoeic dermatitis treatment
Seborrhoeic dermatitis is best treated with a medicated shampoo such as an anti-dandruff or an anti-fungal shampoo such as ketoconazole. For best results, wash the shampoo into the scalp, then wait 5-10 minutes before rinsing. Thick scales can be removed before shampooing by applying a descaling preparation containing coconut oil and salicylic acid for several hours beforehand. If the irritation is severe your doctor may prescribe a steroid scalp lotion, gel or shampoo for occasional use.
Ringworm is not caused by any kind of worm but is due to a simple fungal infection that causes dry scaly hair patches and a classical ‘ring’ of redness in the affected area. It can be passed from person to person, usually via hairbrushes and towels and can also affect other parts of the body such as the groin (known as jock itch) and trunk.
✔️ Ringworm treatment
Ringworm does not usually respond well to antifungal shampoos as the infection goes deep into the hair follicles where shampoos cannot reach. It is best treated with oral antifungal tablets. To help stop ringworm from spreading, start treatment as soon as possible, wash your towels and bedsheets regularly, and take your pet to the vet if it looks as if they might have ringworm (such as having patches of missing fur).
4. Head lice
Head lice are small grey-brown insects up to 3mm long that live on the scalp and can be difficult to spot in the hair. Head lice eggs (nits) are brown or white (empty shells) and attached to the hair. They are most commonly spread by head-to-head contact and can cause an itchy scalp if it is sensitive to the faeces or saliva of the lice. Although most common in children head lice can affect people at any age.
✔️ Head lice treatment
Head lice can be treated with over-the-counter preparations available from pharmacies but the current best advice is to try wet-combing first. Try the following wet-combing tips:
- Buy a special fine-toothed detection combonline or from pharmacies to remove head lice and nits.
- Wash your hair with ordinary shampoo and then apply ample conditioner (any brand conditioner will do).
- While the hair is still wet, comb the whole head of hair, from the roots to the ends.
- This usually takes about 10 minutes to comb short hair, and 20 to 30 minutes for longer or curly hair.
- Repeat this process on days 1, 5, 9 and 13 to catch any newly hatched head lice.
- The hair should be checked again for lice on day 17.
If you have tried wet combing for 17 days but live head lice are still present, ask a pharmacist for treatment.
Psoriasis is a common skin disease affecting 1 in 50 people, occurring equally in men and women and appearing at any age. Psoriasis is a long-term condition which may come and go throughout your lifetime, and is not infectious. It often affects the scalp and about half of people with the most common form of psoriasis (called plaque psoriasis) have scalp involvement. It causes a dry, scaly itchy rash that typically affects the hairline at the back of the head often giving the false impression that it is severe dandruff.
✔️ Scalp psoriasis treatment
Scalp psoriasis is usually treated first with a coal-tar based shampoo and there are several such shampoos for treating scalp psoriasis available from your local chemist. These shampoos are designed to treat the scalp rather than washing hair so you can use a normal shampoo and conditioner afterwards to reduce any smell of tar. When using a tar shampoo you should massage the shampoo into the scalp and leave for 5-10 minutes before rinsing out. Tar shampoo alone is not recommended for treatment of severe scalp psoriasis (ie where there is thick scaling and redness) but is usually effective if there is only relatively mild flaking.
If this is not effective your GP may prescribe a strong steroid lotion (avoid using on the face and ears) that is used for a few weeks to bring the psoriasis under control. This can then be gradually phased out, switching to maintenance treatment with a coal tar shampoo.
Occasionally, Vitamin D derivatives – available as ointment, gel or lotion – can be used in troublesome scalp psoriasis. These usually applied to the scalp once or twice a day and do not need to be washed out. They also do not smell or stain clothing, and are relatively easy to use.
Itchy scalp prevention tips
If you have a condition such as psoriasis it may be extremely difficult to prevent this occurring but as a general point always wash your hair regularly to remove any built-up oils, and always in warm rather than hot water as this can help to prevent scalp irritation and drying. Try to avoid using scalp products containing fragrances, dyes or chemicals, and do not share items such as combs, brushes, hats and towels with other people.
Natural treatments which can be effective for an itchy scalp that does not require medical treatment include:
- Apple cider vinegar:used as a warm water rinse after shampooing the hair.
- Organic coconut oil:coconut oil contains the saturated fat lauric acid that can soothe an irritated scalp.
- Peppermint oil: when used in a diluted form this can reduce scalp itch, and is best used by massaging into the scalp before shampooing.
- Tea tree oil: this has antifungal and antimicrobial properties and should be used as a diluted preparation, mixed in with an ordinary shampoo.