It seems that you are having pemphigus foliaceous.
It is not simple dandruff or seborrhiec dermatitis.
Pemphigus foliaceus is an autoimmune disease
The building block cells of the epidermis are called keratinocytes. These cells are cemented together at special sticky spots called desmosomes. In pemphigus foliaceus autoantibodies bind to a protein called desmoglein-1, which is found in desmosomes in the keratinocytes near the top of the epidermis.
It may be exacerbated by sun exposure.
Certain drugs like captopril, penicillamine
, nifedine may provoke PF.Topical steroid
with antibiotics may be used.
Oral steroid may be taken for long time in tappering dose.
Antimetabolite ..like azathioprine
may be taken.
But, you should consult eminent dermatologist
Dr. Ilyas Patel MD