In most cases, dandruff is irrelevant from a health point of view, but even so we tend to attach tremendous importance to it. Having 'snowy' shoulders is not just cosmetically unbecoming: it can often be seen as a social handicap which can traumatise those who suffer from it and affect their life in public.
Celebrities happily talk about what they see as their physical problems, but it is unusual to find anyone brave enough to tell us what they have suffered as a result of having dandruff. It has been referred to in a few cases, but these tend to be rare, like model Tyra Banks and the Beatles, for example, who, when asked whether their long hair was actually a wig, answered that if it was it would be the first one with dandruff.
«This is one of the most common problems that people consult us about, and it can sometimes cause problems with selfesteem,» said pharmacist María José Cejas, a specialist in dermopharmacy.
The term 'dandruff' is misleading in a way, because we use it to describe different phenomena which lead to excessive flaking of the scalp. The skin in this area differs from that in the rest of the body because of the abundance of hair follicles and the corresponding sebaceous glands, which lubricate the hair and are at a different level in every person. Just as occurs with all of our skin, the epidermis of the scalp is constantly being renewed, so cells continue to fall from the most superficial layer, the stratum corneum, but in some individuals this natural process proves to be problematic, massive and, above all, immediately visible.
«In a healthy adult, around one hundred million flakes of skin fall every day, and the vast majority of them consist of a single cell. In people with dandruff the rhythm of this movement is much higher and a greater proportion of flakes have more than one cell.
Many, in fact, contain several hundred or even thousands of cells. In the most serious cases of dandruff, the weight of the flakes can be 20 times greater than someone without dandruff,» say British researchers Michael Wilson and Philippa J.K. Wilson. Traditionally, there is a distinction between the so-called dry skin dandruff, with fine white flakes, and oily skin or seborrheic dandruff, with larger flakes which look more yellow in colour and are sticky.
It is not entirely clear why some people have dandruff and others do not. «Its origin isn't as simple as people think. In fact, the real cause has yet to be determined by the scientific community, but what we do know with absolute certainty is that it is not associated in any way whatsoever with a lack of hygiene,» say sources at the Spanish Academy of Dermatology.
There are certain determining factors in the production of dandruff such as the amount of oil produced by the glands and the activity of a fungus called 'Malasezzia furfur' (which forms part of the microbiota of our skin), but also the time of year (it is more common in cold weather), pollution or even stress and diet. It is most common after puberty and during the adult age, although, once again, it is impossible to determine definitive boundaries because children and elderly people can suffer from it as well.
«Dandruff is produced as a result of a seborrheic dermatitis of the scalp. This is a common inflammatory process which affects over half of the population and it manifests itself as a reddening, itching and flaking,» explains Dr Sergio Vañó, a dermatologist and expert in trichology, in other words, the speciality which studies the hair and scalp.
«There are several types,» he says. «In one, the fine flaking is predominant, while in the other the flakes are larger and they stick to the scalp. There are some patients with very intense seborrheic dermatitis, which almost enters in the spectrum of scalp psoriasis.»
In fact, its similarity to other pathologies can lead to error: «In a serious case, it is advisable to consult a dermatologist to diagnose the problem correctly and select the best treatment. There are other problems associated with the scalp which can be confused with a seborrheic dermatitis, such as psoriasis, ringworm or primary scarring alopecias,» says Dr Vañó.
In less serious cases, people with dandruff tend to turn to trial and error with the numerous products which are available on the market. This sector moves millions and millions of euros every year (250 million a year in the US alone) but it should be remembered that it is actually impossible to eradicate dandruff permanently.
«There is no way to do that, because it is a chronic process in which outbreaks occur, often through stress. However, there are therapies to improve it swiftly. The most effective involve anti-inflammatory medication, and are used in the most active outbreaks. Then, to keep the problem at bay, there is a wide range of shampoos which can be useful for most patients,» says Dr Vañó.
«The first thing,» says María José Cejas, «is to carry out a good diagnosis; see whether it is dry skin or oily dandruff, whether it is associated with capillary loss or high levels of stress, evaluate the symptoms of flaking and itching... the products are effective when the diagnosis is done properly. We're not only talking about shampoos, but also lotions, calming serums, capillary exfoliants, etc.»
This array of anti-dandruff products is based on active ingredients such as corticoids (which reduce inflammation), antifungals (to reduce the proliferation of Malasezzia) and keratolytics, and keratinisation regulators (which control the production of oil and its adherence to the dead cells).
However, the experts stress that often we sabotage the treatment ourselves, because our concern over the dandruff doesn't always correspond with how disciplined we are in combating it.
«Every anti-dandruff product includes different active ingredients to combat the symptoms,» say sources at the Academy of Dermatology.
«Some have to be applied to the head and left for a few minutes, while others should not be left on for long. It is important to follow the instructions on every shampoo carefully,» they insist.