What are the causes of seborrheic dermatitis?

The causes of this pathology are not all clearly identified, and its origin is certainly multifactorial, involving sebum, a microscopic lipophilic fungus (the yeast Malassezia furfur), and can be a dysregulation of the immune system.

Sebum

Although sebum does not seem to be the cause, the appearance of plaques in areas rich in sebaceous glands suggests the major role exerted by sebum in this pathology. If it is not the responsible agent, it promotes its development.

Malassezia yeasts

Malassezia yeasts are naturally present in the skin flora, and their density is much higher in the areas where the disease develops. The bacteriological analysis of the plates made it possible to highlight an increased concentration of this yeast at the level of the lesions. It therefore seems that it is involved in seborrheic dermatitis, although the mechanism linked to its exaggerated proliferation is not fully understood.

Thus, the excess of sebum combined with the proliferation of yeast will induce an inflammatory reaction, causing an accelerated renewal of the cells, at the origin of the scales of dander characteristic of seborrheic dermatitis.

The immunity at stake?

An immunity disorder is also mentioned as a possible cause of this dermatosis, implying an exaggerated immune response by some people to the development of the yeast Malassezia. The prevalence of seborrheic dermatitis in HIV patients seems to corroborate this hypothesis.

What are the treatments for seborrheic dermatitis?

The treatment for seborrheic dermatitis aims to reduce the proliferation of the yeast Malassezia, to fight against inflammation, and to reduce excess sebum. They use local care products to gently cleanse, eliminate dander and calm irritations. For relapses and more severe forms, a drug treatment based on antifungal active agents may be necessary.

Seborrheic dermatitis is a chronic disease that progresses by flare-up. This inevitably involves alternating relapses and remissions, which weaken the skin in the long term. It is for this reason that care for seborrheic dermatitis combines specific products with flare-ups, but also suitable daily hygiene, based on mild active ingredients, for the face and hair in order to limit recurrences and flare-ups.

Drug treatments

The most used local antifungal treatments use drugs based on ketoconazole and ciclopirox olamine.

Ketoconazole is an antifungal active which destroys fungi by acting on their membrane. It is available by prescription only as a cream or shampoo.

Olamine ciclopirox is also an antifungal substance which acts on the metabolism of fungi to destroy them. It also has an anti-inflammatory action and is widely used, especially in the form of shampoo. In addition, it has the advantage of being available without a prescription.