Hi there.  I finished my targeted therapy (Phesgo) in August 25 after taking it for a year.  I also have been plagued by stinging, itchy rash mainly on my upper arms, sometimes shoulders and back of neck.  Because I have also been taking heart meds (the Phesgo caused reduced heart function) it has been difficult to establish the cause of the rash but I strongly suspect Phesgo.  

I too was prescribed Fucibet and Xysal antihistamines which did very little to calm it.   I am now using Aveeno gel moisturiser which is more expensive than the body lotion but after daily use for about 3 weeks it does seem to have calmed the affected areas down a lot. I don’t scratch half as much as I did. 
I’m hoping, as the Phesgo fully clears the system that the itching will clear up.  But I’ve had a full lymph node clearance as well and I read that that, along with the effects of radiotherapy could also contribute to skin problems. 

I too have been plagued by severe itching since December 25. I’ve tried lots of antihistamines which didn’t work ….then went onto amitriptyline / -  that seem to exacerbate the itch.  I’m now on pregabalin which may be helping. I finished my injections six weeks ago but the itching is still with me.  Does anyone have any idea how long it takes to go away, after the treatment finishes? 
thanks  

I too have been plagued by severe itching since December 25. I’ve tried lots of antihistamines which didn’t work ….then went onto amitriptyline / -  that seem to exacerbate the itch.  I’m now on pregabalin which may be helping. I finished my injections six weeks ago but the itching is still with me.  Does anyone have any idea how long it takes to go away, after the treatment finishes? 
thanks  

The only thing that seemed to soothe the itching a bit was the Aveeno products   
Other than that it has simply been a question of time.  Now that I am a year on since my last Phesgo dose my itching has  pretty much stopped. 
I think it’s just a question of passage of time.  
I still sometimes experience a bit of itching.  But I guess when you have lots of scar tissue from surgery and then radiotherapy damage on top of that these are all factors which can cause and prolong the itching.  
the good news is that the passage of time really does help and you start to feel much more “normal “ again.