Seborrheic dermatitis

1. Pathogenesis

1.1. Malassezia furfur

1.2. Parkinson disease

2. Clinical features

2.1. sharply bordered erythema

2.2. greasy yellow scales

2.3. location

2.3.1. scalp

2.3.2. external ear

2.3.3. retroauricular fold

2.3.4. nasolabail fold

2.3.5. eyebrows

2.3.6. eyelashes

3. Histology

3.1. acanthosis

3.2. parakeratosis

4. DDx

4.1. Pityriasis rosea

4.2. otomycosis

4.3. allergic contact dermatitis to glass frames