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This is a plain English summary of an original research article. The views expressed are those of the author(s) and reviewer(s) at the time of publication.
Doxycycline (an established antibiotic) may be a safer first option than the standard steroid treatment for people with the autoimmune skin condition bullous pemphigoid. The condition causes severe, itchy blistering.
This NIHR-funded study showed that people started on doxycycline were 19% less likely to have severe, life-threatening or fatal events during the next 12 months than those who started a steroid (prednisolone). Blister control was considered acceptable for both treatments (74% treatment success with doxycycline at six weeks compared to 91% with a steroid).
Whole-body steroid cream treatment might give better results, but is not always practical. Oral steroids are often used instead. This study also suggests that doctors and informed patients might consider a trial of doxycycline first, only switching to an oral steroid if needed.
Why was this study needed?
Bullous pemphigoid is an intensely itchy condition which causes large blisters on the skin. It affects about one in 10,000 people in the UK each year, mainly aged over 70. The oral steroid prednisolone is standard treatment. It usually controls the condition quickly, but carries the risk of serious side effects, including mood disorders and infections. Whole-body, daily, application of potent topical steroid creams has been shown to work, but can be difficult for elderly patients.
Antibiotics in the tetracycline group, such as doxycycline, have been used to treat bullous pemphigoid, because they have an anti-inflammatory effect. But there is not much research on their use.
A survey of UK dermatologists found most were willing to accept a 25% reduction in the effect of controlling blisters in the short term, for a reduction in serious adverse effects of treatment of at least 20%, compared to prednisolone. The study was designed to see if doxycycline was worse (or no worse) than this.
What did this study do?
The Bullous Pemphigoid Steroids and Tetracyclines (BLISTER) study was a non-inferior randomised controlled trial carried out in dermatology clinics in the UK and Germany.
Researchers recruited 278 patients. They were randomly assigned to start either 0.5mg/kg body weight prednisolone or 200mg doxycycline daily, for six weeks. After six weeks, blistering was assessed independently, and doctors were able to switch treatment if necessary. People could use up to 30g steroid cream as required for the first three weeks, and again after six weeks.
Researchers recorded all serious adverse events possibly related to treatment, for up to 12 months.
This was a well-designed trial across multiple centres and the results are likely to be reliable. As the researchers knew that steroid treatment is effective, they designed the trial to see if doxycycline was an “acceptable” alternative within the margin of being 25% less effective with a 90% confidence limit up to 37% less effective.
What did it find?
- Prednisolone worked better for blister control, with 74% of people taking doxycycline and 91% of people taking prednisolone having three or fewer blisters after six weeks’ treatment. This gave a difference of 18.6% after adjusting for disease severity (90% confidence interval [CI] 11.1 to 26.1) which was within the acceptable upper margin for non-inferiority of 37%.
- Fewer people had adverse events with doxycycline. Within 12 months of treatment, 18% of people taking doxycycline and 36% of people taking prednisolone had severe, life-threatening or fatal events related to treatment - an adjusted difference of 19% (95% CI 7.9 to 30.1.
- While there was no association between the relative success of either treatment and the severity of the disease, both treatments were less successful in patients with more severe disease.
What does current guidance say on this issue?
The British Association of Dermatologists 2012 guideline on bullous pemphigoid recommends use of systemic and topical steroids. It says that anti-inflammatory antibiotics such as tetracyclines are used widely and “may be considered as treatment in adults, perhaps in combination with topical corticosteroids”.
It also recommends considering the use of nicotinamide, a form of Vitamin B3. However, they stress that at the time of writing, there were no large randomised controlled trials on which to base these recommendations.
What are the implications?
The study provides much-needed evidence about the comparative efficacy and safety of two widely-used drugs for bullous pemphigoid, which should help doctors and patients decide which treatment is preferable for the individual.
Dermatologists could propose a trial of doxycycline in conjunction with topical steroids as a first treatment strategy. This might be most appropriate for those most at risk of serious side effects from systemic oral steroid treatment.
This evidence could strengthen the recommendations in future updates to guidelines on this topic.
Citation and Funding
Hywel C Williams, Fenella Wojnarowska, Gudula Kirtschig, et al. Doxycycline versus prednisolone as an initial treatment strategy for bullous pemphigoid: a pragmatic, non-inferiority, randomised controlled trial. Lancet. 2017;389(10079):1630-38.
This project was funded by the National Institute for Health Research Technology Assessment Programme.
Bibliography
NHS Choices. Bullous Pemphigoid. London: Department of Health; 2015.
Produced by the University of Southampton and Bazian on behalf of NIHR through the NIHR Dissemination Centre
