Licochalcone A: unusually for this site, the comparator is a prescription steroid

A 2018 trial at Siriraj Hospital in Thailand. Randomised, prospective, investigator-blinded.

80 participants with mild to moderate facial dermatitis were randomised.

• test moisturiser — containing 4-t-butylcyclohexanol (described as a sensitivity regulator) and licochalcone A
• control — 0.02% triamcinolone acetonide (TA) cream, a topical steroid

For the first two weeks each group used what it was assigned, twice daily. For the following two weeks everyone used only the test moisturiser. Assessment at baseline, week 2 and week 4, using clinical assessment by investigators, bioengineering measurements, patients' own evaluation and clinical photography.

Results:

• Both showed statistically significant improvement over baseline at two and four weeks — on physician assessment, skin hydration, transepidermal water loss and the patients' visual analogue scale.
• On the patients' own evaluation, TA improved sensation sensitivity more rapidly.
• The authors conclude: the test moisturiser was slower than 0.02% TA at improving facial dermatitis, but showed greater benefit in erythema control and skin hydration.

How to read it.

First, there is something lost and something won in the same result. This site particularly wants to record results like that as they came. Speed to the steroid; redness and hydration to the moisturiser. Which is 'better' depends on what you want.

Second, it is not licochalcone A alone. 4-t-butylcyclohexanol was in there too, along with the moisturiser base itself. This result cannot be read as licochalcone A's. It is the problem we set out on ectoine, snail mucin and onion extract.

Third, there is no vehicle-only arm. An active went into both. So from 'both improved over baseline' you cannot subtract two weeks of time and the act of applying something consistently.

Fourth, only the investigators were masked. A moisturiser and a steroid cream differ in texture and packaging. The participants very likely knew which they had, and the items they scored themselves are affected by that.

Fifth, the design changes after two weeks. Everyone was on the test moisturiser from then on, so the difference between groups at four weeks is mixed with carry-over from the first two.

So it sits at 'early evidence'. The comparator being a prescription steroid is an unusually firm condition for this layer; the other four points do not allow more.

The instrument part of the same trial. We keep it separate from the entry above because the way of measuring is different.

• Skin hydration — the test moisturiser was better than the topical steroid.
• Transepidermal water loss (TEWL) — the improvement after four weeks of the test moisturiser was comparable with two weeks of 0.02% TA.

We carried that second line across as written. The authors put it that way for a reason — it took twice the time to reach the same place, which is the same story as 'slower to improve' in the entry above.

Why this has its own entry.

The key endpoints above were a score assigned by a physician and a score assigned by the patient. Here it is a value read by an instrument. This site writes that difference onto the badge — the one above reads 'instrument measurement'.

And in this trial that distinction overlaps with the result. Hydration and TEWL read by an instrument are more trustworthy in this design than scores from unmasked participants. That the moisturiser beat the steroid there is the firmest part of this page.

It is not a surprising result, though. Compare a moisturiser and a steroid cream on hydration and you are comparing on the thing the moisturiser is built to win. A steroid is a drug for damping inflammation; moisturising is not its purpose.

So the accurate reading is this — this moisturiser does a job the steroid does not. And the job the steroid does — calming inflammation quickly — the steroid did better.

Early evidence. 80 people, one trial, and the four limits above apply here too.