Hi, Seborrheic dermatitis is a multifactorial disease. Exact cause is not known. But, Stress, anxiety,tension, sleeplessness, excessive sun exposure..etc may exacerbate or precipitate the disease. Melassezia..a yeast may be responsible for the condition. Oily skin (seborrhoea),Familial tendency or a family history of psoriasis, Immunosuppression due to organ transplant, human immunodeficiency virus (HIV) infection and others,Neurological and psychiatric diseases like...Parkinson disease, tardive dyskinesia, depression...etc may be associated with seborrheic dermatitis. There may be pink yellow flakes on scalp and other seborrheic areas..axilla, groin,chest,paranasal area..etc You consult dermatologist for firm diagnosis and treatment. Steroid in tappering dose,antihistaminics,antibiotics and antifungal tablets may be considered. Medicated shampoos containing ketoconazole, ciclopirox, selenium sulfide, zinc pyrithione, coal tar, and salicylic acid, used twice weekly for at least a month and if necessary, indefinitely....and steroid scalp applications reduce itching, and should be applied daily for a few days every so often. I hope you got my answer. Thanks. Dr. Ilyas Patel MD