Seborrheic dermatitis: most effective dietary supplements

Seborrheic dermatitis is a chronic, relapsing dermatosis that affects approximately 1 to 3% of the adult population. It presents with erythematous, scaly lesions located in areas of greatest sebaceous activity, such as the face, scalp and trunk.

Pathophysiology

Seborrheic dermatitis is linked to two main factors: an overproduction of sebum (seborrhea) and the presence of Malassezia yeasts, which proliferate in sebaceous-rich skin areas. However, seborrhea alone is not sufficient to explain the onset of the disease, because the lipid composition of the skin is similar in affected individuals and healthy subjects. The involvement of the yeast is supported by the fact that lesions mainly appear in areas where it is present in high density, and by the effectiveness of antifungal treatments. However, symptom severity is not always correlated with the amount of yeast, which suggests that the patient’s immune response also plays a role in disease development.

Symptoms

Symptoms of seborrheic dermatitis vary depending on the body areas affected. On the face, erythematous plaques with greasy scales often appear in the nasolabial folds, the eyebrows, the glabella and the anterior scalp. The scalp may be affected by fine, nonadherent dandruff or, in more severe cases, by thick scales. On the trunk, annular plaques with scaly borders typically appear in the presternal region (base of the neck and chest). Other areas, such as hair-bearing and genital regions, can also be involved. In newborns, seborrheic dermatitis presents as yellowish crusts on the scalp (cradle cap) and face, with possible involvement of the axillary folds and the diaper area.

Risk Factors

Certain conditions increase the risk of developing seborrheic dermatitis. HIV infection is associated with more extensive and severe forms of the disease, often resistant to treatment. People with Parkinson's disease are also more prone to marked seborrhea and severe forms of dermatitis. The condition is also more common in patients with mood disorders, partly due to reduced sun exposure. Individuals with chronic alcoholism and cancers of the upper aerodigestive tract also have a higher prevalence of seborrheic dermatitis.

Treatment

Treatment of seborrheic dermatitis is primarily based on the application of topical care. Antifungals in the form of creams or gels, such as those containing ketoconazole or lithium gluconate, are used to reduce yeast proliferation and decrease inflammation. For scalp lesions, medicated shampoos containing zinc pyrithione, ketoconazole or selenium sulfide are effective. Topical corticosteroids can also be used short term to treat very inflammatory forms. However, because of the chronic nature of seborrheic dermatitis, frequent relapses often occur after stopping treatment. It is therefore essential to educate patients about the importance of regular maintenance and the need to follow long-term treatment to manage symptoms.