What are the causes of seborrheic dermatitis?

Seborrheic dermatitis causes

The exact cause of seborrheic dermatitis is unknown, but several theories include fungal infection or hormone imbalances. Patients with seborrheic dermatitis have an excessive overgrowth of fungal yeast on the skin. Seborrheic dermatitis may be caused also by genetic and environmental factors, as it tends to run in the family. Environmental factors include excessive UV or sunlight exposure and stress. Seborrheic dermatitis is more common in HIV patients.