Here is a picture
I had this. I have Celiac disease. I have dermatitis herpetiformis, which goes with Celiac disease. I do not know if these bumps are DH or if it is another problem just caused by malnutrition that Celiac disease causes. But is this your only symptom or do you have other signs of malnutrition?
The first shampoo I would recommend trying is called Nizoral shampoo. It is pricy but it is helpful for clearing many scalp conditions and it also helps regrow hair.
I do many, many things to restore my health. My scalp is much better, but I would say that shampoo was key.
Here is another one: Home Health Psoriasis Medicated Scalp and Body Wash
Decrease sugar, increase veggies. Get tested for Celiac disease.
Soak scalp in warm water with Epsom salts. Take magnesium and vitamin D supplements. So many things I do for my health and my scalp is much better.