Hi, I have a skin irritation on my head, initially i thought it was dandruff as i used to have that problem with change of place and water when i travel, but one year back when i contacted it and using shampoo like selsen blue also didn t help i visited a dermatologist. she prescribed me a tar shampoo and a tube of sorvate-c , it did help and reduced it. but now i am having a second outbreak it forms redish lump with excessive scratching causes the skin to rupture, and using tar shampoo isnt helping what could be the reason or this, also i am Diabetic TYPE- LADA, age 33, Male. thanks AT