Lots of people have experienced dandruff problems, which may be so heavy to look like snow flakes on their shoulders and causes a lot of embarrassment.

Sometimes the dandruffs may not be simple dandruffs, but are actually features of another skin disease such as psoriasis or seborrhoeic dermatitis, in which cases they are much thicker and bigger.

Where Does Dandruff Come From?

The cells at the bottom layer of the skin split and the new cells will migrate upwards to replace those that have aged, died, and shed off at the surface. Under normal circumstances, this process is done in a controlled manner; the dead skin shed off in the scalp is hardly noticeable.

When the process is out of control in some diseases, the cells at the bottom may divide rapidly, with large number of unhealthy cells moving up the layers. The skin is thickened and the dead skin at the surface will be shed off more rapidly. The faster the shedding, the more dandruff will appear and become very noticeable.

Causes of Dandruff

It is not quite understood how this normal shedding process is disordered. Different theories include hormonal imbalance, bacterial or fungal contamination, food, excessive oily secretion, environment, and stress. None of these is confirmed to be a factor.

Normal excessive dandruff is usually small, and there is no inflammation or itching in the scalp. However, those in seborrhoeic dermatitis and psoriasis are much bigger and more severe.

Seborrhoeic Dermatitis

It is due to the presence of a fungus called Pityrosporum ovale. Apart from the heavier dandruff, the scalp is oily and itchy. There is inflammation, affecting the scalp, the eyebrows, the sides of nose, the chest and the back.

For details, please go to Skin Problems > Common Skin Problems > Eczema / Dermatitis > Seborrhoeic Eczema.

Psoriasis

Psoriasis can affect any part of the body. It appears as thick red plaques on the skin, with shinny scales on the surface. When it affects the scalp, the thick and greasy dandruff may matt together as a large piece and stick tightly to the hair. It can be very difficult to wash off or treat.

The cause of psoriasis is not known, but about 2 % of the population has it, and family genetic has a major role in its happening.

For details, please go to Skin Problems > Common Skin Problems > Psoriasis

Management & Treatments

It depends on whether there is another cause. The way to apply the medication is important too, because it has to bring the active ingredients to the affected area, but has to be cosmetically acceptable as well.

Medicated Shampoo

It is the easiest to use. However, due to the short contact time, the effect is small and only suitable to the mildest cases.

Solution

The contact time is longer. It is usually a steroid solution, which is used to reduce inflammation, but it is not too effective in removing large scales of dandruff.

Lotion & Ointment

They are generally messy and more difficult to use, and also difficult to wash off after use. However, if shampoo or solution cannot remove the scales, then it may become necessary. It is left over in the scalp for overnight to dissolve the scales, and is washed off the next morning after combing the hair with a fine-toothed comb, usually with a tar-containing shampoo.

Main Ingredients

Anti-fungals

This is effective for reducing the number of Pityrosporum ovale, which is a fungus causing seborrhoeic dermatitis. These include Sulphur, Zinc pyrithion, Selenium sulphide and Ketoconazole.

Tar

It can be divided into Coal Tar and Pine Tar. It can reduce the cell division, reduce inflammation, and reduce the itchiness.

Salicylic acid

It can dissolve the dead keratinocytes, and clear the scales faster.

Steroid

It is only suitable for use in the case of seborrhoeic dermatitis and psoriasis.

Calcipotriol

It is used only for psoriasis.

Treatment Regimes

Mild Dandruff

Regular, more frequent shampooing is usually all that necessary. Sometimes using shampoo that contains anti-fungals may speed up the result. There is some evidence that taking vitamin B6 may help dandruff.

Seborrhoeic Dermatitis & Psoriasis

Mild

Medicated shampoo is usually enough to control the situation. Selenium Sulphide, Ketoconazole and Pyrithion Zinc shampoos can target dandruff caused by seborrhoeic dermatitis. Tar shampoos can help both seborrhoeic dermatitis and psoriasis.

Moderate

Usually steroid is need. If there are more scales, the steroid can be combined with salicylic acid. Calcipotriol may be considered in psoriasis.

Severe

Apart from continue the use of steroid solution to reduce the inflammation; these resistant scales can be removed by applying an ointment containing sulphur and salicylic acid, which will dissolve the scales after being left in the scalp overnight. The ointment is avoided to mess up the beddings with a shower cap, and it is washed off the next morning with a tar shampoo.