Seborrhoeic dermatitis

Signs and symptoms

The presentation varies with location and intensity, but the typical signs are:

• Fine, yellowish or white, oily peeling on a slightly reddish base.
• Itch of varying intensity — from mild to moderate.
• Feeling oily skin in the affected areas.
• Thicker plates in the most intense cases.
• On the scalp — persistent dandruff, sometimes with larger scales.
• On the face — scaling in the naso-labial grooves, eyebrows, between the eyebrows, behind the ears.
• In babies — the so-called "milk cross", with thick yellow scales on the scalp.

Where it appears

Typical locations correspond to areas with the highest density of sebaceous glands:

• Scalp — the most common.
• Eyebrows and area between eyebrows.
• Nasobial grooves (line from nose to lips).
• Behind the ears and external ear canal.
• Beard and moustache on men.
• Chest, interscapular region and navel in some cases.
• Folds (axillas, groins) in longer frames.

Causes

The cause is multifactorial. Several mechanisms are involved:

• Fungus Malassezia, which exists naturally in the skin and proliferates in sebum-rich zones — it is not an infection, but contributes to inflammation.
• Increased tallow production, with altered composition.
• Exaggerated inflammatory response to normal skin components.
• Individual predisposition — many patients have relatives with the same condition.
• Changes in skin barrier function in affected areas.

Factors that may aggravate

Some factors tend to trigger or aggravate outbreaks:

• Emotional stress and sleep deprivation.
• Season changes — winter tends to worsen by drier air.
• Fatigue and acute illness.
• Excessive alcohol.
• Oily or irritating cosmetics on the scalp and face.
• Associated conditions — seborrhoeic dermatitis is more frequent or more severe in patients with Parkinson’ s disease and immunodepressed.

Diagnosis

The diagnosis is clinical — made by evaluating the lesions and the typical distribution. No routine tests required.

In an online consultation, the dermatologist analyzes photographs of the affected areas and a questionnaire on evolution, products already used and associated factors. With this information you define the treatment plan adapted to your case.

In doubtful situations — when distinguishing from other dermatoses such as psoriasis — the dermatologist indicates whether a face - to - face evaluation or additional tests are necessary.

Options for treatment

Seborrhoeic dermatitis is chronic but responds well to treatment. The aim is to control the outbreaks, relieve symptoms and prolong the injury-free periods.

Frequently asked questions