SEBORRHEIC DERMATITIS CAUSES

The cause of seborrheic dermatitis is unclear, though it is has been linked to genetic or environmental factors. Pityrosporum ovale , a species of yeast normally found in hair follicles, has been proposed as one possible causative factor. A high fat diet and alcohol ingestion are thought to play some role. Other possible risk factors include:

Stress and fatigue
Weather extremes (e. g. hot, humid weather or cold, dry weather)
Oily skin
Infrequent shampoos
Obesity
Parkinson's disease
AIDS
Use of drying lotions that contain alcohol
Other skin disorders (for example acne, rosacea, or psoriasis)