polycythemia vera
"I was diagnosed with polycythmia vera in 2007. Itching, terrible itching, has been my main complaint and hydroxyurea didn't help. I was taking Atarax four+ times a day plus getting light therapy 2-3 times a week. With Jakafi, I take Atarax 1-4 x day, and don't need light therapy. However, when it's really warm or allergens are in the air, I take Emend off-label. 
Side effects of Jakafi: more susceptible to infection, possibly anemia, possibly higher erythropoietin levels."