Hi
Pityriasis rosea may resolve spontaneously. This may be aggravated by hot water, prolonged exposure to water and an allergic component has been associated with it. This skin condition has been present for almost a year, you say. I suggest that you have this followed up with an infectious disease specialist aside from your dermatologist. The diagnosis of pityriasis rosea may need to be reevaluated. Topical corticosteroid may be able to help relieve the skin condition as well as UV therapy.
Hi,
Pityriasis rosea usually lasts 1 to 3 months. In most patients, the condition lasts only a matter of weeks; in some cases it can last longer (up to six months).
If it lasts longer than this then you should be investigated for other possibilities like Psoriasis,Eczema or Ringworm infections because thay can all produce similar looking lesions.
The rash of this condition usually goes away on its own, no treatment is required. Calamine lotion or zinc oxide cream can be applied on the rash to relieve the itching.
Anti-histamine medications can also be used for the same purpose.
Steroid pills/ointments can be recommended to hasten the clearance of the rash in some cases.
ref:http://familydoctor.org/online/famdocen/home/common/skin/disorders/808.html