Dandruff is white or slightly gray in color. While dry dandruff tends to be small and small-shaped, greasy dandruff develops larger and also thicker scales due to the adhesive property of sebum. The most affected area is usually the crown of the head, while the nape of the neck usually has little or no dandruff. Possible accompanying symptoms are itching, inflammation and a feeling of tension in the scalp. Dandruff is the most common disorder of the scalp. Depending on the source of information, the number of people affected varies between 23% and 70%. In winter, the symptoms often worsen.
The most common cause is yeast fungi of the genus , especially and (see also under pityriasis versicolor). They are natural components of the skin flora that feed on lipids. Dandruff therefore occurs mainly in people with high sebum production after puberty. The fungi feel very comfortable on the scalp because a moist climate is created by the sweat glands and the sebaceous glands supply lipids as nutrients. In addition, combing and styling cause small injuries, which further facilitates the colonization of microorganisms. The lipids from the sebum are broken down by the fungus into fatty acids, which irritate the skin, leading to an acceleration of cell renewal. Other causes:
- Increased sebum production (seborrhea), seborrheic dermatitis.
- Decreased sebum production due to atopic dermatitis, age, frequent hair washing or degreasing shampoos.
- Head lice (dandruff are empty or full egg cases of the insects!).
- After a sunburn
- Irritation caused by hair styling
Risk factors include allergies, puberty, an unsuitable hair care products, stressful hair styling (frequent hair coloring, perming, hair straightening, etc.), pregnancy, certain medications and an unbalanced diet.
Diagnosis is based on clinical appearance and can be supported by various quantitative bioinstrumental methods (microscope, squamometry). The medical history must include diseases such as psoriasis and allergic causes such as hay fever, asthma, and atopic dermatitis. Factors affecting the hair must also be taken into account. For example, how often is the hair washed, what products are used for this purpose or what stress hair is exposed to (perming, hair straightening, hair coloring or bleaching). Possible differential diagnoses include eczema of various causes, such as allergic eczema, contact dermatitis, seborrheic eczema (large, yellowish and greasy scales and signs of inflammation), atopic dermatitis, psoriasis and filamentous fungal infections (tinea capitis, limited scaling of the head associated with hair loss).
For dry dandruff, hair should be washed less frequently and degreasing shampoos should be avoided. For oily dandruff, hair should be washed daily.
Shampoos are predominantly used to treat dandruff. Depending on the cause of dandruff, different active ingredients are used: Antifungals:
- Ketoconazole (Terzolin, Nizoral).
- Ciclopiroxolamine (Sebiprox).
- Dipyrithione (Crimanex)
- Selenium disulfide (ectoselenium, selsun).
- Urea (Turexan Capilla, Linola Urea, Carbaderm).
- Salicylic acid
Keratostatics / antiproliferative agents:
- Zinc pyrithione + disodium undecylenamido MEA-sulfosuccinate (Squa-med).
- Formerly coal tar (now obsolete).
- Piroctonolamine (eg Eucerin anti-dandruff shampoo).
Herbal remedies (selection):