I Lost Alot Of Hair After A Month Long Hospital

I lost alot of hair after a month long hospital stay last march/april. I had an irregular heartbeat and they shocked my heart to get it to beat normal. I also had pneumonia. The hair is growing back but i have had a problem with white small scabs forming on my scalp that are very itchy! I don't know what is causing this or how to get rid of it. I have tried different shampoos but they come back and i pick them off! Please help! Thank you.