Acupuncture for CSU

Stimulated by Zheng et al 2023.[1]

CSU – chronic spontaneous urticaria
EiC – editor in chief
MCID – minimal clinically important difference
UAS7 – urticaria activity score (weekly sum of daily measures of itch and wheal severity)
CI – confidence interval

key to acronyms

This is the first large sham controlled trial of acupuncture in CSU (n=330). CSU is referred to in the press as chronic hives. Whilst it is just out today in Annals of Internal Medicine, I first saw the paper for peer review 7 months ago. I had forgotten about it until I received an invitation from the EiC of Annals to consider writing an editorial to accompany its publication.

CSU has featured on here already this year. One of the large retrospective cohort studies from Taiwan looked at the incidence of hypertension following CSU and whether or not this was affected by having acupuncture after diagnosis: Hypertension risk in CSU 2023.

The results of the current trial demonstrate efficacy of acupuncture over sham and waiting list control, but the size of the effect did not quite reach what is deemed to be clinically relevant in this condition ie a minimal clinically important difference (MCID). Having said that, the primary outcome (UAS7 score) did drop by 10 points (the MCID adopted for this measure) from baseline at 5 weeks, and somewhat further at 7 and 8 weeks. Unfortunately, the a priori primary outcome time point was set at 4 weeks, before the maximum benefit was realised.

Personally, I think MCIDs should always be assessed within group from baseline, which is the same way they are calculated in the first place, but most journal editors want the MCID applied between groups at the primary outcome time point. In this case, I guess I could live with it being applied against waiting list, but definitely not against sham.

All the secondary outcomes in this trial were significantly in favour of real acupuncture over sham or waiting list apart from days on antihistamines, which had a wide CI in both comparisons.

So, what about the treatment used? 16 sessions of manual acupuncture were applied over a 4-week period – 5 times a week in the first 2 weeks and 3 times a week in the third and fourth weeks. The points used were LI11, SP10, ST36, ST25, SP6, HT7, and CV12. The sham involved the same number of sessions using the Park sham device applied to non-points –points away from classically described acupuncture points and meridians. Interestingly, the sham location for CV12 was a point on either side of the midline, so whilst a real acupuncture session involved 13 needles, the sham version had 14 (non-penetrating needles) applied.

Despite knowing next to nothing about CSU, I agreed to write an editorial to accompany publication of the trial.[2] I used my entire allowance of words and references, and managed to mention data on reduced mortality from using EA in both laboratory animals and humans with sepsis. My tenuous link was systemic inflammation, and I was astonished to find that my editorial was accepted without the need for revisions. By comparison, I had a hideous time with editors from another general medical journal closer to home, when I was asked to write a pro-acupuncture debate piece on pain.[3]

In the process of writing the editorial I naturally checked some relevant references on the subject and found a paper from 10 years ago on a biologic drug (omalizumab). The patients were much more severe at baseline in this trial – almost 50% higher scores on the UAS7. The change from baseline in the active drug group was 19, so about twice the MCID in the condition. Acupuncture may well have had a larger effect in this more severely affected population, but it is unlikely to have matched this monoclonal antibody.

Having said that, the cost of a 6-week course of omalizumab is just over £3k, which will get you about 87 treatments from me in the BMAS London Teaching Clinic. That is over 5 courses of treatment equivalent to that used in this trial. It sounds as though acupuncture might be more cost effective, although we will have to wait for more robust calculations than that before getting excited about treating chronic hives.

References

1          Zheng H, Xiao X-J, Shi Y-Z, et al. Efficacy of Acupuncture for Chronic Spontaneous Urticaria : A Randomized Controlled Trial. Ann Intern Med. Published Online First: 14 November 2023. doi: 10.7326/M23-1043

2          Cummings M. Acupuncture for Chronic Spontaneous Urticaria. Ann Intern Med. Published Online First: 14 November 2023. doi: 10.7326/M23-2713

3          Cummings M, et al. Should doctors recommend acupuncture for pain? BMJ. Published Online First: March 2018. doi: 10.1136/bmj.k970

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Declaration of interests MC