90% female (increasing in males)
Topical or inhaled corticosteroids
use of cosmetics
physical (UVB, heat, wind)
microbiological (fusiform spirilla, candida)
hormonal factors (premenstrual deterioration, use of oral contraceptives)
GI tract abnormalities (malabsorption)
Emotional stress
Atopic dermatitis
Candida dermatitis
Cercarial dermatitis
Contact dermatitis
Dermatitis herpetiformis
Diaper dermatitis
Dyshidrotic dermatitis
Neonatal seborrhoeic dermatitis
Nummular dermatitis
Perianal streptococcal dermatitis<unk> 
Poison Oak, Ivy, Sumac dermatitis
Seborrheic dermatitis
Stasis dermatitis
Perioral dermatitis
Rosacea
Tinea capitis
Seborrheic dermatitis
Lichen sclerosus
Acne vulgaris
Lichen planus
Facial demodicosis