Seborrheic dermatitis
From dermoscopedia
Introduction
Seborrheic dermatitis is a common, chronic inflammatory skin condition affecting areas rich in sebaceous glands, including the scalp. It's characterized by erythema and flaky, greasy scales. Dermoscopy, also referred to as trichoscopy when examining the scalp, is an invaluable tool in diagnosing and managing this condition.
Clinical Features of Seborrheic Dermatitis
- Scalp Lesions: Manifest as dandruff to dense, yellow, greasy scales with underlying erythema.
- Distribution: Often affects the scalp, but can also involve the face, chest, and back.
Dermoscopic Features
Scalp Examination
- Yellow-White Scales: Greasy and adherent to the scalp.
- Erythematous Background: Diffuse or patchy red areas under the scales.
- Hair Shaft: Normal hair shaft appearance, without significant variation in diameter or structure.
Additional Findings
- Follicular Plugging: Occasionally observed.
- Vascular Patterns: Mildly increased vascularization may be seen around the follicles.
Differential Diagnosis
Dermoscopy helps distinguish seborrheic dermatitis from other scalp conditions such as:
- Psoriasis: Exhibits thicker, silver-white scales with more pronounced red loops in capillaries.
- Tinea Capitis: Shows broken hairs and black dots in severe cases.
Yellow, interfollicular scaling in patient with seborrheic dermatitis.
