Chapter 37: Seborrheic Dermatitis

SUMMARY

• Seborrheic dermatitis (SD) is a common condition characterized by accumulation of scales, oily, red, and flaky scalp, often accompanied by itch.

• Patients with severe forms often complain of an increased hair loss.

TIPS FOR DIAGNOSIS

• The more common affected areas of the scalp seem to be the forehead and the back of the ears beyond the hairline, but seborrheic dermatitis can also extend to other parts of the face, such as eyebrows and nasolabial folds.

• Mild forms producing flaking, itching, and moderate scalp erythema make differential diagnosis based exclusively on clinical examination difficult to determine.

• Trichoscopy can be useful for differentiating scalp seborrheic dermatitis from scalp psoriasis: beside the difference in color and thickness of scales the observation of scalp vessels is crucial.

TIPS FOR TREATMENT

• Malassezia scalp quantity is elevated in affected patients and antifungals are usually efficient for symptom management.

• In general, cosmetic and pharmaceutical products for treating seborrheic dermatitis include keratolytic, regulators of sebum production, soothing agents, antifungal drugs, and/or antimicrobial products.

• Because SD is also considered as an inflammatory disease, topical low- and mild-potency corticosteroids are popular treatments due to their anti-inflammatory properties.

DON’T FORGET

• SD can be very worrisome for affected individuals and may significantly impact their quality of life, causing stress, depression and anxiety.

• Dandruff is the most frequent clinical sign and it affects approximately half of the adult population worldwide.

• Malassezia plays a key factor in triggering inflammatory process and hyperproliferative epidermal reaction that characterized SD.

PITFALLS AND CAUTIONS

• Heredity seems to play a small role in developing a predisposition for SD, while climate changes, physical trauma (such as scratching), seasonal variations, and emotional stress seem to aggravate clinical presentation.

• Impaired function of the stratum corneum of the scalp may also be predisposing for the development of SD.

EXPERT PEARLS

• SD is described in 1%–5% of the general population, a percentage that rises to 30%–33% in immunocompromised patients.

• Regardless of etiology, in most of the cases, patients just want to find a proper and efficient treatment for their scalp problem, with no interest of knowing what is the main cause of their scalp problem.

PATIENT EDUCATION POINTS

• SD has a higher prevalence and severity in men than in women, due to hormonal factors and among young people than older people, probably due to the increased sebum production that occurs during adolescence and early adulthood.

• Although both of these flaky conditions are not life threatening, they have a significant negative impact on patient’s quality of life, leading to social distress.