Hi,
The symptoms could be due to a condition called Seborrhoeic dermatitis. It is an inflammatory skin disorder affecting the scalp, face, and trunk causing scaly, flaky, itchy, red skin.
The cause of seborrhoeic dermatitis remains unknown, although many factors have been implicated. The widely present yeast, Malassezia furfur is involved, as well as genetic, environmental, hormonal, and immune-system factors. Side effects to inflammation may include temporary hair loss.
It could also be due to Psoriasis of the scalp. Scalp psoriasis and seborrheic dermatitis can be difficult to differentiate. Both are common conditions that affect the scalp. In addition, they share similar symptoms, such as itchy, red, scaly skin and burning /soreness of the scalp.
Treatment is the same for both, which is shampoos containing coal tar, ciclopiroxolamine ketoconazole, selenium sulfide, or zinc pyrithione.
ref:http://en.wikipedia.org/wiki/Seborrhoeic_dermatitis
Have your thyroid checked hyperthyroid sound about right , did you r\o fungal of scalp alopecia areta try a topical hydrocortisone cream 1% OTC or coal tar shampoos