What Causes Facial Flushing In The Morning That Subsides By Evening?

Hi, i am at my witts end... I will try to make this as short as possibe. I started having severe facial flushing about 1 year ago. went to derm dr. and he sais maybe rosasea but he was not sure. did all treatments for rosasea including metrogel, oracea,antibiotics,etc... it continued and the derm said he did not think it was rosasea. I pursued with my reg dr and he ran some tests. ruled out lupus but was tested positive for HIV. Went to HIV specialist and he cant figure it out either. He has me on low dose systemic steroids (2mg daily methyprednisolone) My symptome are severe flushing in the morning and subsides in the afternoon and evening like clockwork every day... Gets so red and flush that it is hot andsomewhat painful. any ideas??? derm senf me to medical dr. med dr wants to send me to derm??? I am so upset and hopeless at this point.