What Causes Red Itchy Spots On Head, Neck And Shoulders?

My wife has several red itchy sports on her head and neck and shoulders. She describes them as Feeling like they re biting me - This has lasted for the past several months and the local Dr. says it s probably psychosomatic. They prescribe antibiotics and benedril but it never works. I think it looks like a reaction to a shampoo or a conditioner or maybe a reaction to some of her other meds or vitamins - but I don t know - any ideas?