The first international forum on dandruff and scalp health in 2007 initiated by IACD was held in Shanghai on July 4, 2007. Authoritative scalp health experts from Sweden, Britain, Germany, Thailand, China and other five countries conducted academic discussions on topics such as scalp health, scalp differences between men and women, causes of dandruff, nourishing and removing dandruff, and were interviewed by reporters in order to find a solution to the persistent dandruff breeding problem in Asia. In addition, Unilever, an industry representative, was also invited to release a phased experimental report on the project to solve the dandruff problem in China.
Causes and harm of dandruff
Lawrence Charles parrish, MD, President of International Society of Dermatology, Clinical Professor of Dermatology and Dermatobiology, Director of Jefferson International Dermatology Center. Main research interests: plastic dermatology, skin history, infectious diseases, tropical dermatology, cosmetic applied science and skin infection research.
Reporter: At present, the problem of dandruff in Asia has attracted the unanimous attention of experts from many countries. So what are the causes of dandruff and its harm to human body? What is the direct relationship between dermatitis and dandruff?
Professor Lawrence: Normal hair growth is generally 300 ~ 400 μm/ day. Hair can be divided into three growth cycles: growth period, regression period and rest period. For the scalp, its growth time is 5 ~ 7 years. Dandruff is an observable shedding on the scalp surface, which is a precursor of seborrheic dermatitis. This may be a step-by-step process, from the beginning to redness, irritation to scalp desquamation, and finally to real seborrheic dermatitis.
Patients with excessive sebum secretion often complain that "hair is always oily". In fact, sebum is a mixture of squalene, wax and sterol esters, cholesterol, polar lipids and triglycerides. If there is too much oil secretion, it may cause inflammation, which is what we call seborrheic dermatitis. In fact, this is a kind of chronic dermatitis that is difficult to define. From the morphological point of view, it is unique, red, with clear injury edge and covered with oily dirt. At the same time, it is also very characteristic in distribution, always distributed in areas rich in sebaceous glands.
Seborrheic alopecia of the head is not only the most common local pathological manifestation, but also the most important one, which is also the reason for baldness in adolescence. Clinically, the problem of scalp oil is mainly concentrated in young men. Some young people with intractable skin lesions even doubt whether they are infected with AIDS. According to incomplete statistics, due to the high humidity in sultry summer, the hair and scalp have formed a small "greenhouse effect", which will focus on the problem of scalp oil and dandruff, so young men should not panic.
Some foolish ideas think that washing your hair is harmful and you can't wash your hair every day. If it were not for the influence of this view, the probability of this situation would be even smaller. In fact, for people with oily hair, it is best to wash your hair every day.
Dandruff and Malassezia
Chip removal function
Doctor of medicine, professor of venereology and dermatology. Main research interests: dermatology, immunology, dermatopharmacology and malassezia-related diseases.
Reporter: At what age does dandruff often appear? What role does Malassezia flora play in dandruff? What ingredients can the shampoo for dandruff hair use to relieve symptoms?
Professor Jan: Usually from after puberty, dandruff symptoms are the most serious around 40 years old. Many studies show that the population incidence of this disease is about 15% to 20%. This is a chronic disease with recurrent attacks. This part will turn red and peel off, and be covered with fat dander. Dandruff should be the mildest seborrheic dermatitis. There is no need to go to the hospital because of dandruff.
Malassezia can be separated from various parts of human body and skin diseases, and Malassezia syncytium and Malassezia globosa can be separated from healthy people. However, Malassezia globosa, Malassezia obtuse, Malassezia restrictive, Malassezia conjoined and Malassezia furfur can be isolated from the body suffering from seborrheic dermatitis. Dandruff contains all kinds of lipophilic Malassezia, among which Malassezia restrains, Malassezia globosa and Malassezia obtusifolia are the most common. Dandruff caused by restricted Malassezia is easier to treat because restricted Malassezia is more sensitive to antibacterial treatment.
Observation shows that the immune response in seborrheic dermatitis and malassezia folliculitis shows the stimulation and activation of the immune system. However, the activation of inflammatory interleukin and TH 1 and TH2 regulatory interleukin was also observed. When yeast cells can be observed in hair follicles, the staining is usually deep. This result is similar to that found in Candida albicans.
Therefore, it is effective to use the shampoo containing zinc pyrithione twice a week for 4 weeks. Similarly, using ketoconazole shampoo twice a week for four weeks, and then using it once a week or once every two weeks as a preventive measure can also effectively reduce the number of Malassezia; Using selenium sulfide shampoo twice a week for four weeks can also effectively treat dandruff.
Reporter: Which shampoo containing these three ingredients will have better effect? What treatment is usually the first choice?
Professor Jan: Zinc pyrithione and ketoconazole are both effective in treating dandruff. Even a shampoo combining the two has been developed, and the shampoo containing zinc pyrithione is more effective than the shampoo containing coal tar. Ketoconazole is more effective than selenium sulfide. Using the shampoo containing ketoconazole, the recurrence interval of dandruff is better than using the shampoo containing ciclopirox amine.
Stress and cold weather in winter are harmful to most cases of dandruff. Patients with nervous system diseases and immunosuppression disorders are not sensitive to the treatment of dandruff. Antifungal therapy is a more effective method to treat dandruff, because it can reduce the number of Malassezia, the effect is more lasting than corticosteroids, and the recurrence interval is longer. Therefore, antifungal therapy is the first choice.
Scalp is also skin.
Anthony Rollins, MD, inventor of nearly 50 patents. Main research interests: ceramide and barrier lipid, α hydroxy acid, optimized wetting agent system, vitamin A adjuvant, desquamation. Main research fields: skin biochemistry and dysfunction, skin oil and moisturizing, cosmetics and applied science of dermatology.
Reporter: Everyone has Malassezia on their scalp, so does everyone have dandruff?
Dr Anthony: Of course not. Dandruff is a disease caused by many factors. Malassezia is only one of the factors leading to dandruff, but it also needs to be controlled. People with dandruff can obviously feel the oiliness of hair and scalp; Itching is aggravated; Hair is not soft enough to comb easily. People with healthy scalp don't feel this way.
Reporter: So can anti-dandruff shampoo solve the problem of itching and oil, and can it solve the problem of substandard?
Dr. Anthony: The decrease of scalp barrier function and lipid substances leads to dandruff scalp peeling, peeling and itching. Inflammation is an important cause of dandruff, which will affect hair quality and growth. Therefore, as long as the inflammatory reaction is handled properly, the scalp condition will be improved, thus making people's scalp healthier and achieving the effect of hairdressing.
Therapeutic strategies for scalp problems
Mike philpott, MD, expert in hair biology and professor of skin physiology. Main research interests: human hair growth, human hair follicle sebaceous gland unit, defensins and acne, keratinocytes. Research fields: human skin appendages, cell biology, biochemistry related to hair growth, sol-gel and the culture of sebaceous glands in hair follicles.
Reporter: What are the current treatment strategies for scalp problems?
Dr. Mike: The current treatment methods include immunosuppression, local or systemic use of glucocorticoid, allergic/contact dermatitis induced by immunotherapy, infiltration of target immune cells, etc., but these methods have not solved the problems of hair follicle cycle and disintegration of hair follicle immune system.
Therefore, some comprehensive methods should be taken, including T cell inhibition, restoring the immune immunity of hair follicles and inhibiting degeneration.
Therapeutic strategy1:The use of TLR antagonists is generally related to stimulating inflammatory response. When GSK3 inhibitor stimulates the expression of IL- 10, it stimulates TLR and down-regulates inflammatory cytokines IL- 1B, IFN-γ and IL-6.
Treatment strategy 2: the amount of TLR-2 in acne is up-regulated, while the amount of TLR-2 is down-regulated by retinoic acid. TLR may be a potential anti-acne target, and other potential inhibitors of downstream signal transduction system should be developed. FLICE-like inhibitory protein (FLIP) inhibits the activation of NF-KB.
Differences of scalp problems between men and women
Yang Qinping, MD, professor of dermatology, Huashan Hospital, Fudan University, China. The main research directions are integrated traditional Chinese and western medicine, androgenetic alopecia, acne and chloasma. Research fields: pathogenesis and treatment of alopecia, integration of traditional Chinese and western medicine in dermatology.
Reporter: Asians have always had the phenomenon of "dandruff flying all over the sky", and the dandruff problem has also been "named" by the International Health Organization. What is the difference between Asians and other races? Why are Asian scalp problems so serious?
Dr. Yang: Asians have thicker epidermis, faster cell proliferation and developed sebaceous glands. In addition, the unique lifestyle and traditional Asian diet structure also make the scalp condition of Asians very different from other races. Because Asians pay less attention to the care of head skin than Europeans, they pay more attention to shampoo and scalp, which leads to insufficient nourishment of scalp and is seriously lower than the health index.
Compared with early washing and dandruff removal, scalp nourishment has become a new development direction in this field. Conventional washing can only relieve dandruff symptoms on the surface. To eradicate dandruff, scalp nourishment is the key. As long as we develop good washing habits, pay attention to choosing shampoo suitable for Asian scalp structure and physiological characteristics, and pay attention to scalp nourishment, we can effectively inhibit the growth of dandruff and prevent hair loss and oil production. Only by supplementing all kinds of nutrients needed by the scalp in a balanced way can we protect our hair better. Because of the different scalp conditions of men and women, the degree of oil production and sebum shedding is also different, and the shampoo products for male and female consumers should also be different.
Reporter: So what's the difference between male and female scalp problems?
Dr. Yang: General scalp problems can be roughly divided into: seborrheic alopecia, also known as androgenetic alopecia (AGA), excessive sebum secretion and dandruff. Among them, the incidence of AGA has racial differences, and the general situation is as follows: Caucasian >: yellow > black. Caucasian males (Caucasians, for example): 30% have AGA at the age of 30, and 50% have AGA at the age of 50. It usually happens before the age of 40. Female: The onset is generally later than that of male 10 years, and there are two peak ages of onset, 20-30 years old and 40-50 years old. Generally, the onset is more serious after menopause. The sampling survey of AGA prevalence in Shanghai shows that the prevalence rate of male is 65438 09.92%, that of female is 3.05%, and the average age is 46.5 years old.
The main factors of male AGA are genetic quality, DHT level in scalp and serum, type ⅱ 5a- reductase activity and androgen receptor. The androgen dependence and genetic factors of women are not as obvious as those of men, so the incidence rate of women will be lower than that of men. It is difficult to diagnose AGA in women, and a series of laboratory tests (such as blood routine, thyroid function, serum iron and other endocrine tests) are needed. ) and need to be distinguished from other resting hair. Sometimes it can be accompanied by hirsutism, acne, decreased menstrual flow or polycystic ovary syndrome.
According to the clinical manifestations of male AGA, male alopecia can be divided into 7 grades according to the progress of head alopecia, that is, I ~ II grades are mild; Grade ⅲ ~ ⅴ is moderate; Grade ⅵ ~ ⅶ is severe.
Sebaceous gland is the target organ of androgen. People with strong androgen secretion secrete more sebaceous glands, especially after puberty. Men are more affected by androgens, so they are more likely to cause sebum overflow. Clinically, the increase of alopecia and seborrhea obviously affects the quality of life of patients. Therefore, effective measures must be taken to reduce sebum overflow while treating premature alopecia. 565 cases of premature baldness in men were investigated clinically. The results showed that 7 1.3% patients had oily hair, and 42.5% patients often had dandruff. To sum up, there are some differences between male and female scalp problems, and several scalp problems are also interrelated. Therefore, it is necessary to take targeted measures according to personal circumstances to deal with scalp problems.