Clinical Appearance of Seborrheic Dermatitis on Face and Hair
Seborrheic dermatitis presents as symmetric, poorly defined erythematous (red) patches with yellow, oily scales and fine superficial flaking, predominantly affecting sebum-rich areas of the face and scalp. 1
Scalp Manifestations
- Yellowish, greasy scales with adherent flaking that may be misdiagnosed as simple dandruff 2, 3
- Dull or yellowish-red patches with overlying scales that are characteristically greasy in appearance 3
- The condition is chronic and relapsing, with seasonal worsening common in dry winter months 4
- Unlike scarring alopecias, seborrheic dermatitis does not permanently destroy hair follicles 2
Facial Distribution and Appearance
The face shows a distinctive pattern in sebaceous-rich areas: 3
- Nasolabial folds (creases from nose to mouth corners) with red, flaking patches 4, 5
- Glabella (area between eyebrows) 5, 3
- Eyebrows with scaling and redness 4, 3
- Ears and retroauricular skin (behind ears) 5, 3
- Cheeks and nasofacial folds 3
- Periauricular skin (around ears) 3
Key Visual Characteristics
- Well-demarcated patches that are symmetric on both sides of the face 3
- Yellowish, greasy scales overlying red patches (the hallmark appearance) 3, 6
- Fine, superficial desquamation (flaking) 1
- May present with blepharitis showing erythematous eyelids and potential eyelash follicle destruction 3
Important Variations in Skin of Color
- Erythema may be less apparent in darker-skinned individuals 1
- Hypopigmented, scaly macules and patches may be the presenting sign rather than redness 5, 1
- Arcuate or petal-like patches (termed "petaloid seborrheic dermatitis") may be seen specifically in darker skin 5
- Postinflammatory pigmentary changes might be more prominent than redness 1
Clinical Pitfalls to Avoid
- Do not confuse with psoriasis (may be called "sebopsoriasis" when resembling psoriasis), which requires different treatment 2, 4
- Distinguish from atopic dermatitis and contact dermatitis, which have different therapeutic approaches 2
- Scalp involvement is often mistaken for simple dandruff, delaying appropriate antifungal treatment 2
- In children of color, the classic "cradle cap" appearance may not occur; instead look for erythema, flaking, and hypopigmentation in skin folds 5
Associated Findings
- 95% of patients with seborrheic blepharitis also have seborrheic dermatitis elsewhere on the body 2, 7
- The condition is more pronounced in HIV infection, Parkinson's disease, and Down syndrome 2, 7
- May co-occur with dry eye conditions in 25-40% of cases 2
- Patients presenting with sudden onset severe seborrheic dermatitis should be screened for HIV risk factors 3