Thank U for prompt answer. You will be a saint if U can cure my misery.
Oral medication: Yes for several months I took antihistamines (Loratidine, Hydroxyzine HCL25mg, Cetirizine, Benadryl) which helped a little at first but now no more effect at all.
Blood test: Yes I had a blood test which didn't suggest anything. Then the scrape test which ruled out the mites and the fungus. Finally biopsy which ruled out psoriasis, eczema, and mites.
Ointments: Yes I used fluocinonide, triamcinolone, clobetasol which all helped at first but no more effect afterward.
UV: Yes the doctor who thought I had psoriasis gave me the UV treatment twice a week totally about 24 sessions. It helped by 50% but not 100% cure. I was told to stop UV half-way in order to have a biopsy. Should I resume the UV?
Now I am worsened and suspect only two remaining possible causes aforementioned: Skin allergy to the incense smoke; or skin dried by the gas heater. I stopped the incense burning 6 weeks ago but condition didn't improve. May be the incense smoke deposit on the ceiling after 10 years accumulation still disperses into the air (?)
If it is one kind of eczema like U said, then is there a cure? (I was told that eczema had no cure.)