Uncontrolled itching

Hi Dr. Agar,

I am on daily nocturnal home hemodialysis - I do about 7 hours each night, six nights a week. I run at a blood flow rate of 250 ml/min and a dialysate flow rate of 500 ml/min. I have been at this for almost 8 years now. Before that I was on PD and in centre hemo.

For the past couple of months I have been having really bad itching. The itching is mainly on my legs and feet with bursts around the stomach and shoulders. My Phosphorus is within normal limits. So is my Calcium. My nephrologist suspected it could be allergic and put me on anti allergic medicines for about 10 days. To no avail. During my almost 17 years on dialysis, I have never had a problem with itching.

I was wondering if you had any insights into what might be causing this?

Thanks so much!

Kamal

Dear Kamal

I doubt it is your dialysis or your Ca/PO4/PTH balance from what you say … but your other post notes that you are on cinacalcet. This can, not uncommonly, cause itch and is a potential issue here. While you haven’t said how long you have been on it and whether that matches, in time, the onset of your symptoms, it is certainly a candidate culprit.

As you PTH has fallen to the adynamic bone disease range, your cinacalcet should have been be ceased by now - at least I hope it has been - so let’s see if in a week or 10 days, the symptoms have abated.

Yes Dr. Agar, the cinacalcet and calcitriol have been stopped. I will keep a watch an update after about a week or 10 days. Thanks so much!

Hi
What is cinacalcet? I also have uncontrollable itching. I take 2 calcitrol a week Monday and Friday. I take Renvella 2 with meals and 1 with snacks. My numbers are good. Protein level is down a little but am working on that. I also take all other meds that go with dialysis treatment. I do PD every night for 10 hours on the cycler. I have tried oils for dry skin and lotions for itching such as Calaclear. Only temp relief. Dr prescribed Hydroxyzine but that doesn’t seem to work either. Itching is very hard to deal with. I don’t sleep well because of it. Can you help.
Thank you
Jane

I will let Dr. Agar answer the question. But I wanted to post an update that my itching has totally gone!. Not sure what helped though! It could be the stopping of the cinacalcet or it could be that my Phosphorus is now quite low (about 1.8 mg/dl) and that could have also reduced the itching.

Thanks
Kamal

Kamal … That is good to hear. I suspect it may have been the cinacalcet, especially if it settled within a week or two after ceasing it.

Jane … Cinacalcet is a calcimimetic - a drug that ‘mimics’ or ‘looks like’ calcium to the calcium receptors on cell surface of the cells that make up the parathyroid gland. Theses calcium ‘receptors’ are molecular ‘sensors’ which, when calcium binds to them, start a chemical reaction within the parathyroid cells to make PTH. When a patient takes cinacalcet, the drug occupies the sensor receptors and calcium cannot. This blocks the way calcium triggers the production of PTH and the PTH level falls. I suspect Kamal had an allergic response to it as (Kamal) your PO4 was at the time normal.

As for your itch, Jane, itch is a hugely common problem for dialysis patients and, in most instances (though not in Kamal’s case) is due to calcium/phosphate problems. You said your ‘numbers are good’ but I am afraid that does not give me enough information to be able to pinpoint the cause.

It sounds as if it is something that needs careful assessment by your nephrologist and he/she is clearly the best placed to track the reason down. However, while there usually IS an explanation for itch, sadly there is not always a cure.