Histamine and PV

[Omphalos]

Hi Everyone,

I'm newly diagnosed with PV at the age of 49, and am largely symptom-free at the moment, which I am still surprised by considering my haematocrit at diagnosis was 0.70!

Home has been Sydney for the last 18 months (I'm from the UK) and I feel like I'm receiving great care from the Kinghorn Cancer Centre, which so far has been genetic testing to identify the JAK2 mutation and a fairly aggressing course of venesection, up to twice a week. I seem to have stabilised my haematocrit in the mid 0.4s with a monthly venesection and no meds yet.

As many people probably do, I'm looking back at vague symptoms over the past few years to see if anything fits the usual sympton profile: I definitely had the redness of face (which I only see now it's gone) and occasional scintillating scotoma/visual disturbance.

I don't experience any itching, but have for several years had recurrent hayfever-like symptoms that seemed unrelated to the time of year or where I was, so difficult to pin down as an allergic reaction. Does anyone know if this is a possible consequence of higher histamine, linked to raised red blood cell counts? Do some people get itching and others get less clear symptoms?

My first post. Thanks for the great community we have here, which I've found very useful over the past few months.

[hunter5582]

It is plausible that this could be related to the deregulation of the JAK-STAT pathway causing an increase in histamine levels but would be difficult to nail down. It could be caused by something else. Regardless of the cause, a daily dose of an antihistamine may control the symptoms. Sugggest you consult with your care team and devise a plan.

[Omphalos in reply to hunter5582]

Thanks Hunter! I'll raise it at my next appointment.

[hunter5582 in reply to Omphalos]

Saw your comment about PEG. I had itching as a side effect from PEG and Besremi. There is a less common side effect where the interferons can overactivate mast cells, releasing excess histamine. This is what the antihistamine works to control the side effect. It is worth noting that cetirizine usually works better than some of the other antihistamines for itching.

[SoledadBarcelona]

Of course!. There is a possible relationships between mastocytosis and polycythemia vera.

[kamiilos]

Hi, I actually experience itching after starting Pegasys journey about a year ago. Before that just fatigue and red face I'd say.

Welcome to the group.

[Omphalos in reply to kamiilos]

Thanks!

[Fieldsy57]

Hi Omphalos, welcome to the group! I was diagnosed with PV in September 2023 but looking back there were signs that I have had it for several years before. Particularly when I went skiing my legs in particular were itching like crazy on a few ski trips in the later years before I was Diagnosed. Looking back in now makes sense so the next time I go i will be taking the antihistamines and we will see how it goes. I take them daily now and it has improved the itching though if I am wearing something tight, even a belt, on a hot day I still come up with itching lumps. My conclusion is that it seems to be worse in my case in areas where the body gets hot and sweaty. Hoping the antihistamines do the job. Good luck.

[Omphalos in reply to Fieldsy57]

Thanks Fieldsy, the antihistamines seem to work for me too.

[SoledadBarcelona in reply to Omphalos]

Try also Black cumin or called Nigella saliva on skin or eating it. Good luck!