Even with the same 'dryness,' the medication to apply differs—A pharmacist rethinks moisturizers for CKD patients

"Hono-san, this patient has been complaining of severe itching lately. Their heels are starting to crack; should we apply something?"

One afternoon, I was stopped by a
nurse in the hospital ward hallway.

An 80-something patient.
They have been in the convalescent rehabilitation ward for a few weeks following a cerebral infarction.

A day when the same "dryness" looked different

I headed to the patient's room to see their heels, and
the heels were cracked and fissured.

The skin on the front of the lower legs was peeling off crisply like fish scales.
Meanwhile, the upper limbs were dry and white, as if covered in powder.

── Even though it is the same "dryness," it looks different.

Feeling a sense of unease, I returned to the station and opened the medical chart.
The first thing that caught my eye was the trend in eGFR.

28 six months ago, 25 three months ago, and 22 now.
It is gradually declining...

Checking their medical history, I saw CKD G4 due to diabetic nephropathy.

Actually, before looking at the chart and just hearing the story, I
thought, "Maybe I should suggest a heparinoid."

The heels were cracked and dry.
I thought, "Heparin should be fine for now, right?"

But when I lined up the fish-scale skin on the lower legs, the powdery skin on the upper limbs, and the eGFR numbers,
my hand stopped.

── Perhaps this might not be "just dryness."

The skin is also a voice from the kidneys

In my previous article, I wrote about the thin skin of patients who have used steroids for a long time.

And before that, I wrote about the skin of patients who cannot move due to sleeping pills.

Looking at it this way, I feel like I only write about skin (laughs).
Both are stories about a pharmacist standing at the intersection of medicine and skin.

Also, in this article, I organized the medications that pharmacists look at for pressure ulcer prevention into six items—but moisturizers are not among those six items.

However, since this is a situation I actually encounter often in the convalescent rehabilitation ward, I want to write about it.

The skin is also a voice from the kidneys.

When looking at kidney function values,
I also want to look at the skin.

Cracked heels, scaly lower legs, powdery skin on the arms.
Could these be voices from the kidneys?

Three mechanisms of skin dryness in CKD

Why is the skin of CKD patients
different from 'ordinary dryness'?

In clinical practice, I am conscious of the following three points.

1. Sebum and sweat decrease

As CKD progresses, sweat gland function declines due to uremic toxins and autonomic nervous system effects.
The sebum film becomes thinner, making it easier for moisture to escape from the skin.
It is described as 'increased transepidermal water loss (TEWL),' but in terms of clinical feel, it is'skin that is prone to dryness.'That is what it means.

2. Natural Moisturizing Factors (NMF) in the stratum corneum decrease

The stratum corneum of the skin contains NMF (Natural Moisturizing Factors) to retain moisture.
These include amino acids, urea, and lactic acid.
In CKD, it is said that the distribution of this NMF changes, and because the barrier function declines, it becomes easier to pick up external stimuli.

3. The balance of Ca, Pi, and iPTH is disrupted

When kidney function declines, the regulation of Ca (calcium) and Pi (phosphorus) breaks down, and iPTH (parathyroid hormone) rises. As this progresses, skin calcification or intense itching (uremic pruritus) may occur.

── The appearance of the skin changes depending on the speed at which these three mechanisms progress.

Therefore, when considering moisturizers for CKD patients,
'Heparinoid because it is dry' alone
is sometimes not enough.

Not 'dangerous,' but 'use selectively'

This is the part I most want to write about today.

When looking at the skin of CKD patients,
I value the perspective of'not dangerous, but use selectively.'

'Urea-containing preparations for CKD patients should be avoided due to concerns about percutaneous absorption' ── I have read articles stating this several times.

Theoretically, that may be true.
But when I actually look at the patient's condition,
I want to think about it a little more.

The way I selectively use them in my mind is something like this.

Urea for Keratinization

When the heels are cracked, the lower legs are fish-scale-like, and powder falls off when touched with a finger—when I see skin like that, I consider proposing a urea preparation.

Unlike heparinoid, urea preparations have a keratolytic effect. They soften hardened keratin from the inside.
For the 'keratinization and xeroderma' common in CKD patients, I think this is often a better fit.

Sometimes, a nurse will tell me, 'Even using Hirudoid, the hardness of the heels doesn't change.'
In those cases, I propose a urea preparation to the attending physician.

Heparinoid for Reduced Barrier Function

If the skin is dry overall, but
there is no localized hardness or keratinization,
then I think a heparinoid is suitable.

This is closest to what is generally imagined as 'dry skin'.
Moisturizing, promoting blood circulation, and maintaining barrier function.
I consider it the first choice when I want to condition the skin overall.

If there are cracks, I revert to white petrolatum

This is the most important point.

Areas with cracks, erosions, or inflammation on the skin have increased percutaneous absorption.
In the case of CKD patients, I consider this to be a step up in risk.

It is not necessarily 'dangerous,' but rather a level of 'being aware.'
However, for those specific areas, I want to have the option to withdraw both urea and heparinoid, and let the skin rest with petrolatum or azulene.

Once healed, I return to the previous usage.
It's just that,
but I want to make sure I don't forget this 'reverting' process.

Three things to do before consulting the attending physician

The prescription itself is decided by the doctor who sees the overall picture.
I think about this rough differentiation, and I often go to consult the attending physician with this in mind.

However, there are three things I do before that.

1. Go to check the skin condition with the nurse

Before going to the doctor,
I ask for the nurse's opinion once more.
The nurse's judgment is truly indispensable.

'Could you take a look at the skin on the lower legs with me again?'
'Isn't this crack on the heel deeper than last time?'
—I make comments like that.

By having them look at the condition with me, conveying my own opinion, and having the nurse reply, 'Yes, it's deeper' or 'No, it was like this before,' I am able to look at things objectively.

2. Check the trends in laboratory values

Next, organize the laboratory values.

For CKD patients, check eGFR, Cr, P, Ca, iPTH, and Alb.
Track the trends over half a year.

Instead of being surprised by a single number,
look at 'how it has moved over the past six months.'

If you look at it as a line, such as eGFR 28 → 25 → 22,
you can see whether the change is rapid or gradual.

If P is rising,
check if Ca and iPTH are moving along with it.
This is because secondary hyperparathyroidism may be lurking in the background of skin calcification and itching.

3. Do not make judgments. But, summarize the information

Finally,
I have decided that I will 'not decide'.

'This is how the skin looks right now.'
'This is how the laboratory values have moved over the past six months.'
'I am considering urea preparations or heparinoid as candidates for moisturizers, and petrolatum for cracked areas.'

── I summarize this
so that the attending physician can easily make a judgment.

The attending physician is the one who makes the judgment.
I am just gathering the materials for that judgment.

However, just by 'summarizing' this,
there are days when the conversation with the doctor changes.

There are also days when no answer is found

Proposing a urea preparation makes the heels a little softer.
Continuing with a heparinoid settles the dryness.
Protecting cracked areas with petrolatum gives the skin a rest.

── Even so,
this does not stop the progression of CKD.

'Even if you change the moisturizer, the skin condition may not improve depending on the progression of CKD.'
── This is what I tell myself.

Even so, thinking about how to use different agents properly is
a small thing I can do for the patient.

When the proposed medication is not as effective as expected.
When a nurse tells me, 'It hasn't changed much.'
When I look at the eGFR numbers and cannot find any words.

I truly worry about
what I should do at such times.

Even so, I want to maintain the stance of continuing to think together with the nurses.
I want to keep the perspective of wondering, 'Was this choice really the right one?'

There are days when I cannot find the answer.
But I am sure I can at least continue to observe.

This time, I wrote about the skin of CKD patients and
the proper use of different moisturizers.

Not 'dangerous,' but 'using them selectively'.

This is my stance as a certified pharmacist.
Instead of 'avoiding it because of CKD,' I want to
'use them carefully and selectively precisely because of CKD'

Thinking this way, I continue to face
my patients on the ward today.

Both the laboratory test numbers and the skin findings
are signs from the patient.
I want to be able to receive both.

Discharge is not the end.
Including the condition of their skin and kidneys,
life goes on.

That is why I want to continue thinking about
the optimal moisturization for patients with my team on the ward today.
That is how I feel.

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▶ Click here if you want to know the thinking process of a certified pharmacist regarding pressure ulcer treatment and prevention.