What is dandruff: causes, how to recognise it and remedies

Dandruff is a very common scalp condition characterised by the appearance of whitish flakes of dead skin in the hair and, sometimes, on clothing. Although it is neither contagious nor serious, it can cause cosmetic and psychological distress, particularly when accompanied by severe itching, irritation or persistent flaking.

In some cases, dandruff may be a sign of an underlying inflammation, such as seborrhoeic or contact dermatitis. When flaking is frequent, visible or accompanied by symptoms such as redness or lesions, it is advisable to consult a dermatologist to identify the cause and put a targeted treatment plan in place.

What is dandruff and how does it form?

Dandruff is a scalp condition characterised by visible flaking of the skin in the form of whitish flakes. It is often accompanied by itching and, in more persistent cases, by skin irritation or redness.

Dandruff occurs when the scalp’s cell turnover rate is faster than normal. Dead cells, which should normally shed gradually and imperceptibly, accumulate on the surface and clump together to form visible flakes, a condition often exacerbated by the presence of sebum or inflammation.

Its symptoms can vary from person to person, but it tends to be chronic or recurrent, with seasonal flare-ups or episodes triggered by stress, the use of unsuitable shampoos or an unbalanced diet.

Types of dandruff: dry and oily

Dandruff is not always the same: it can take two main forms, which differ in appearance, symptoms and underlying causes:

• Dry dandruff (pityriasis simplex)

  • Fine, dry white flakes

  • They come out of your hair easily and fall onto your clothes

  • The scalp appears dry and sensitive

  • It is often linked to dehydrated skin, cold weather and frequent washing

  • It may cause itching but rarely visible inflammation

• Oily dandruff (mild seborrhoeic dermatitis)

  • Thick, greasy, yellowish flakes

  • They tend to stick to the scalp and hair

  • The scalp appears oily, irritated and red

  • It can also affect other areas rich in sebaceous glands (eyebrows, sides of the nose, ears)

  • It is often associated with excessive sebum production and an overgrowth of the fungus Malassezia furfur

What causes dandruff?

Le cause della forfora possono essere diverse, alcune delle quali potrebbero manifestarsi contemporaneamente:

• the Malassezia furfur (Pityrosporum) fungus feeds on sebum, which is the oily, fatty substance on the scalp. It can contribute to the formation of dandruff because it is an irritant and can increase the production of new skin layers which, in turn, amplifies the shedding of dandruff flakes;
• a poor diet high in fat and low in zinc, vitamin B and healthy fats can worsen dandruff, as can excessive alcohol consumption.
• stress-related dandruff: it can trigger the mechanisms underlying the formation of dandruff or exacerbate the symptoms. Stress is sometimes linked to seasonal changes, during which dandruff problems are more common;
• dry or oily skin can provide the perfect environment for dandruff to form. Skin exposed to dry environments can become irritated and flaky. Instead, for people with oilier skin, dandruff appears as a form of seborrheic dermatitis, a problem that extends beyond the scalp to all areas of the body where sebaceous glands are present (e.g. eyebrows, the corners around the nose, groin and armpits).
• psoriasis: when this condition affects the scalp, it can lead to dandruff;
• irritation or sensitivity caused by hair care products, such shampoos or other cosmetics. These can cause irritative contact dermatitis, triggering the mechanisms behind dandruff.

Symptoms and how to recognise it

Dandruff is a non-contagious condition, but it can be a source of psychological distress, particularly when the flakes are clearly visible in the hair or fall onto clothing.

The main symptoms include:

• Visible flaking: the skin on the scalp flakes off, forming white or yellowish flakes that are either dry or oily, depending on the type of dandruff.

• Itching: often severe, it can lead to frequent scratching, which makes the flaking worse.

• Skin irritation or redness: particularly in cases of oily dandruff caused by seborrhoeic dermatitis.

• Scabs or small lesions: caused by repeated scratching, which can lead to abrasions and an increased risk of secondary infection.

Dandruff or head lice: what’s the difference?

Dandruff and head lice may present similar visible symptoms, such as white flakes in the hair or intense itching of the scalp, but they are two completely different conditions, with distinct causes, characteristics and treatments.

Here’s how to tell them apart:

• Nature of the problem

  • Dandruff: a non-contagious condition caused by flaking of the scalp, often linked to dryness, seborrhoeic dermatitis or other skin factors.

  • Head lice: these are live parasites (insects) that feed on blood from the scalp and are transmitted through direct contact.

• Appearance of the visible particles

  • Dandruff: the flakes are white or yellowish, loose, and fall off easily when the hair is lightly combed or shaken.

  • Nits (lice eggs): these appear as small greyish-white capsules clinging to the hair shaft and are difficult to remove. They are often found just a few millimetres from the scalp.

• Itching
  Both conditions can cause itching, but with head lice the itching tends to be more intense and persistent, particularly at the nape of the neck and behind the ears.

• Presence of the parasite
  On close inspection, in the case of head lice, the insect can be seen moving through the hair, particularly when using a fine-toothed comb on wet hair.

• Contagiousness

  • Dandruff is not contagious.

  • Head lice are highly contagious, particularly among children in schools or community settings.

Diagnosis

Dandruff is both a condition and a symptom. A visit to a dermatologist is usually sufficient to identify the causes of dandruff.

In cases of dandruff caused by seborrhoeic dermatitis or contact dermatitis, a specialist may recommend specific tests, such as allergy tests like the patch test, which can identify the substances that triggered the reaction.

How to get rid of dandruff: treatments and remedies

Dandruff is usually a chronic condition.
To combat it, you can use specialised shampoos or lotions that help control flaking and reduce inflammation, whether you have oily or dry dandruff.

The most suitable products for treatment are those containing salicylic acid and colloidal sulphur. These two ingredients are often combined in a fast-absorbing cream (Dermaclub recommends Crema 2S), to be applied depending on the severity of the dandruff, usually in the evening. This product helps to remove flakes whilst simultaneously reducing inflammatory factors, such as excess sebum and the presence of Malassezia furfur.

An alternative to cream is a lotion containing salicylic acid and glycolic acid (such as Glicosal Lotion), which, thanks to its liquid form, is easier to apply to the scalp or hair-bearing areas.

Shampoos also play a role in treating dandruff.
There are medicated shampoos on the market containing antifungals or cortisone, but these are not recommended, as they can lead to resistance and encourage the return of dandruff. In fact, those suffering from dandruff should keep shampoo use to a minimum and avoid massaging or rubbing the shampoo into the scalp, so as not to further irritate it.

The ideal shampoo should be formulated with non-foaming cleansers and contain a non-pharmaceutical anti-inflammatory agent, such as sulphonated ichthyol (see, for example, Dermictiol Shampoo)

Preventing dandruff: good habits to adopt

To prevent dandruff, it is recommended to:

• avoid situations involving prolonged physical and mental stress
• use gentle, non-foaming shampoos
• reduce the frequency of washing
• dry your hair with cotton towels and do not use a hairdryer
• get some sun if possible: UV rays can actually help reduce dandruff

Dandruff is often regarded as a minor problem, but in reality it can be a visible symptom of a more complex skin condition, such as seborrhoeic dermatitis, an irritant reaction or, in some cases, dermatological conditions such as psoriasis. If dandruff is persistent, recurrent, or accompanied by severe itching, redness or widespread flaking, it is advisable to consult a dermatologist.