Seborrheic dermatitis

1. Histology

1.1. acanthosis

1.2. parakeratosis

2. DDx

2.1. Pityriasis rosea

2.2. otomycosis

2.3. allergic contact dermatitis to glass frames

3. Pathogenesis

3.1. Malassezia furfur

3.2. Parkinson disease

4. Clinical features

4.1. sharply bordered erythema

4.2. greasy yellow scales

4.3. location

4.3.1. scalp

4.3.2. external ear

4.3.3. retroauricular fold

4.3.4. nasolabail fold

4.3.5. eyebrows

4.3.6. eyelashes