What are the symptoms of seborrheic dermatitis of the scalp?
The most common symptom is the appearance of white or yellowish dandruff. However, seborrheic dermatitis can also be associated with redness, itching and even skin lesions on the scalp. In the most severe cases, the inflammation caused by seborrheic dermatitis can irreversibly destroy hair follicles.
Is it common?
Yes, according to epidemiological studies, seborrheic dermatitis affects nearly 2% of the French population. It seems to be more common in men than in women. Furthermore, its prevalence is higher in patients with HIV, Parkinson’s disease or Down syndrome.
What is the cause of seborrheic dermatitis?
The exact origin of seborrheic dermatitis is not known. However, its development seems to be linked to the presence of a large number of Malassezia-type yeasts, which thrive in the sebum of the scalp. Once a certain threshold is reached, these micro-organisms trigger an inflammatory reaction that accelerates the renewal of epidermal cells and causes a process of desquamation, which leads to dandruff. Stress, fatigue, greasy hair, poor hair hygiene, exposure to extreme temperatures, excessive sweating, obesity or pregnancy are all aggravating factors. Despite popular belief, there is no link between diet and seborrheic dermatitis.