Seborrheic dermatitis is a chronic inflammatory skin disorder characterized by fine scaling and erythema mostly confined to areas where sebaceous glands are prominent. Pityrosporum ovale infection is common in seborrheic dermatitis.
The characteristic pattern is based on age group.
In infants it appears as cradle cap. It is a diffuse or focal scaling and crusting on the vertex of the scalp that sometimes accompanied by inflammation.
In young children, there is Tinea amiantacea which is one or several patches of dense, plate-like scales, 2-10 cm in size that appear anywhere on the scalp.
While adolescents have dandruff which are fine, dry, white, non-inflammatory scalp scaling with minor itching.