Could this be Calciphylaxis?

Hello Dr. Agar,

I have been on dialysis for about 14 years now - the last 5 on daily nocturnal home hemo.

For the last few months, I have noticed that my skin, especially on my right arm and hand cuts easily. I barely scrape a wall and I have a scratch. I barely touch a sharp edge and I have a scar. I also keep getting clots below my skin - small circular areas that are black and soft to start with but then over time they become hard and eventually fall off. I get these on my toes and fingers. My platelets are around 120,000. Apparently, the platelets need to be way lower for them to cause these kinds of clots.

I talked to my nephrologist about this and he said it could be a deficiency of vitamins since I would be losing a lot of vitamins during my long dialysis hours. He put me on an additional multi vitamin and Vitamin C for a month. There has been no change in this condition however.

I just visited to my nephrologist again. He examined the scars and thought these cold be initial stages of calciphylaxis. He went on to suggest that I get a renal transplant soon. He said that since I was on dialysis for about 14 years now, these kinds of things will keep coming and bothering me and affecting my quality of life.

The problem is that my native disease is atypical Hemolytic Uremic Syndrome and I have a genetic abnormality (CFH/CFHR1 hybrid) because of which the chances of recurrence of the disease after a transplant is 80%.

Could this really be calciphylaxis? Is there any other way to check this? My latest Calcium is 9.9 mg/dl and the Phosphorus is 2.4 mg/dl. So, the CaXP product is well below 55.


Dear Kamal

It is very difficult, even with your description, to know the cause. I also don’t know some key information – like your medication – and, especially, whether you might be on warfarin as, for example, calciphylaxis can be a feature of warfarin Rx in CKD and dialysis patients.

By my calculations, your Ca++ is 2.475 mmol/l (mg/dl x 0.25) and your PO4 0.77 mmol/l (mg/dl x 0.323) with a resulting Ca x PO4 product of 1.9. If my conversion is correct, it would be unusual to develop calciphlaxis at that low Ca x PO4 product range … though, is that PO4 a pre- or post-dialysis PO4? It seems a low PO4 (even for NHD) to be a pre-dialysis level. If, by my misinterpretation, you have given me post-dialysis levels, then your pre-dialysis PO4 may be significantly higher and, depending on your dialysate Ca++, your pre-dialysis Ca++ may also be different. This might mean that your Ca x PO4 product (for most of your non-dialysis hours) is actually much higher. Can you clarify and confirm that the levels you gave me are indeed pre-dialysis. This would clearly influence my interpretation.

Calciphylaxis is, indeed, a complication of a long dialysis vintage (the number years on dialysis) and while you have been on better dialysis (NHD) for 5 years, your previous 9 years may have been less than ideal.

Sadly, but truthfully, as a result of 9 years when your Ca x PO4 product was not as well controlled as it is now, blood vessel damage (calcium deposition in the wall of the blood vessel which effectively turns them into little limestone pipes rather than being the flexible, porous, nutrient and oxygen-sharing conduits they are designed to be) may have occurred. If this has occured in the earlier years, even subsequent good dialysis will not now be able to reverse the small vessel damage.

Andreas Pierratos has shown the regression of calcium deposition in non-bony sites (including in the walls of coronary arteries) using high resolution coronary CT and MRI to investigate the coronary vessels … but, its not a ‘gimme’ that this would happen and damage done may remain damage done.

While calciphylaxis would not be expected if NHD had comprised your major dialysis component, it is still unfortunately a possible outcome when 9 years of prior low-hour, low efficiency dialysis has preceded the NHD.

If it is calciphylaxis, then the treatment (dialysis) is to get the best dialysis you can (you are), to optimise blood flow as best as is possible - sometimes with the repair of upstream blood vessels, to stop potentially harmful drugs, to lower PTH (eg: cinacalcet etc) … see other previous discussions at this website … and, sometimes, to consider treatments with sodium thiosulphate and/or the use of hyperbaric oxygen (if available) … like it used by divers for the treatment of ‘the bends’.

I am assuming (and hoping) you are not warfarinised. Warfarin can be a ‘promoter’ of calciphylaxis … but there is now thought to be very little place for warfarin in dialysis patients except in special circumstances: such as after certain heart valve replacements etc. As a treatment for simple atrial fibrillation, the data tells us that it warfarin is likely to cause as much grief (or more) than it solves and most would now avoid warfarin in the dialysis setting, if possible. If you are on warfarin, it is best if it can be stopped.

Other drugs (eg: steroids) can sometimes be a problem too … so you need these checked and reviewed by your physician.

You are describing (and remember I am interpreted this without seeing the lesion and from 8,000 km away) what is commonly called an eschar. Again, with the help of Wikipedia (it is strong in giving plausible lay explanations for complex things) an eschar is a ‘slough ‘or a piece of dead tissue on or just under the surface of the skin It can follow burns (not in your case), spider bites (ditto, I think) or it can be due to patchy dry gangrene from small blood vessel occlusion (blockage) to the small vessels of the skin. This, of course, is the main mechanism of the condition we call calciphylaxis in dialysis patients.

Fungal infections or cutaneous (skin-restricted) anthrax infections – both worth considering in India – can also give characteristic black lesions like you describe.

Eschar is sometimes called a black wound because the wound is covered with thick, dry, black necrotic (dead) tissue. Eschar can usually be allowed to slough off naturally, though sometimes can need surgical removal. If an eschar is on a limb, it is important to assess the blood supply of the limb. Re-vascularisation can help – especially if larger blood vessels up-stream are in trouble too – but your doctor will be able to determine this.

Sometimes the best way to sort it out is with an ‘edge’ biopsy from the periphery (edge) of one of the lesions. While calciphylaxis has a rather characteristic appearance on biopsy, some of the other causes might also be sorted out (or excluded) this way.

I doubt it is a platelet issue and I don’t think is sounds likely that atypical HUS is implicated, this far down the track.

Maybe an edge biopsy might be a place to start.

I hope that has helped you a little - and not worried you too much.

PS … I am sorry I have been so slow on the Good Dialysis Index front - I have been way too busy on far too many fronts lately … and I am not getting younger either! However, I will be most interested to hear how it works out in the Indian setting and with Indian targets applied. The key is that it is modifiable, to circumstances and by units (mg/dl or SI), so, keep me posted, and good luck with it.

Thanks so much Dr. Agar for your lucid, detailed explanation of the possible causes.

To answer your questions: No, I am not on warfarin. The Calcium and Phosphorus values I mentioned were actually post dialysis. But the pre dialysis values were not very different. My last pre dialysis Calcium and Phosphorus were almost the same as these values. I will, however, repeat the pre dialysis values just to be sure.

Another thing - I was on PD for six of those earlier 9 years. How does PD fare when it comes to promoting calciphylaxis?

I will discuss about the edge biopsy with my nephrologist.

Thanks again for your answer!


Kamal, if I had to guess (based only on your description and the experiences of others), I’d suspect pseudoporphyria ( You can also see a photo of the condition here: (or just do a Google image search) and compare it to what you are seeing.

This seems to be more of a problem with folks on standard HD, but the article I’ve linked to gives LOTS of clues–including things like vitamin levels. Some vitamins are washed out with dialysis, after all. A drug called Mucomyst in the US (acetylcysteine) has been helpful in some cases.

A good suggestion, Dori … the only thing that put me off that thought was the description … not bullous and waxy but black and dry.

‘Bullous’ is a term which strictly indicates a raised fluid-filled blister … sort of like the fluid-filled ‘blisters’ that occur sometimes after the chaffing of a shoe or after a skin burn … where the skin surface seems to ‘separate’ from the tissues beneath and a clear fluid fills the space.

A biopsy would help to sort it out. But, Kamal, pseudo-porphyria is a great idea to add to the mix of potential causes.

You need to talk it over with your nephrologist.

I looked at the picture and the article you linked to Dori and it does not look like that.But I will discuss this possibility too with my nephrologist. Thanks!



This is a reasonably good image of an eschar:,r:11,s:0

Another is:,r:2,s:71&tx=73&ty=68&biw=1440&bih=680

The ‘bullous’ lesion that Dori suggested seemed less like you description than this.


Even if you do have this kind of problem, don’t get your knickers in a knot … it is not an untreatable problem. Even if it is calciphylaxis … which I have still some serious doubts about - as it is so rare to develop this when as well dialysed (as I believe you are) with NHD … I’d be getting an edge-of-lesion skin biopsy … and go from there!

Don’t get the cart before the horse here … find out 1st … worry second. Even then, worry gently.

Dear Kamal

Thank you for sending some photos (privately) of your hands and toes. Having seen these, and in my view, there is little doubt that these lesions are neither pseudo-porphyria nor, for that matter, calciphylaxis. They look suspiciously embolic.

I think an echocardiogram would be the next investigation to undertake.

Though I have already advised you of this elsewhere, I know you will not mind if I add this response to this discussion for the benefit of those who may have been following this thread.