What Causes Scaly White Rashes On The Body And Swollen Lymph Node On The Neck?

I have a rash over entire body except for face. Thank G-D for that! My skin is covered with scally white scalling skin head to toe. Sometimes itchy sometimes not. I ve have seborrhehic dematitis that never quits despite ketoconozole shampoo. Scalp very itchy. Flakes from head and body all the time! Got dx of immune changed system, lymphadenitis and dermopathy. I have endured this for 8 years. My hair falls out intermittently along with changes in my skin condition. I am so tired of my skin condition I avoid social interaction as I am ashamed of the trail of skin I leave behind. No one has known how to help eradicate this. I have become somewhat of a reclusive due to this. Lymphoma has been ruled out. I had 2 nodes that got enlarged to the point of discomfort removed sugically. I now have a new enlarged node left side of neck I haven t seen about yet. Have a history of thyroid problems in my family. Mother and grandmother had Graves disease. I lost a great amount of weight down to size 2 from 8 at one point and then gained weight. I think I burned up my thyroid after having a fast thyroid. Both my sisters are hypotyroid but never went through loosing a hugh amount beforehand. What can possibly be wrong with me? I had exzema as a child in the back of my arms and legs.