, according to speakers at the annual Integrative Dermatology Symposium.
National Rosacea Society
Persistent erythema in a woman with rosacea
“SIBO is definitely something we test for and treat,” Raja Sivamani, MD, said in an interview after the meeting. Dr. Sivamani practices as an integrative dermatologist at the Pacific Skin Institute in Sacramento and is the director of clinical research at the institute’s research unit, Integrative Skin Science and Research. He led a panel discussion on rosacea and acne at the meeting.
Associations between SIBO and several dermatologic conditions, including systemic sclerosis, have been reported, but the strongest evidence to date involves rosacea. “There’s associative epidemiological evidence showing higher rates of SIBO among those with rosacea, and there are prospective studies” showing clearance of rosacea in patients treated for SIBO, said Dr. Sivamani, also adjunct associate professor of clinical dermatology at the University of California, Davis.
Studies are small, but are “well done and well-designed,” he said in the interview. “Do we need more studies? Absolutely. But what we have now is compelling [enough] for us to take a look at it.”
Findings of rosacea clearance
SIBO’s believed contribution to the pathophysiology of rosacea is part of the increasingly described gut microbiome-skin axis. SIBO has been recognized as a medical phenomenon for many decades and has been defined as an excessive bacterial load in the small bowel that causes gastrointestinal symptoms, according to the 2020 American College of Gastroenterology clinical guideline on SIBO.
Symptoms commonly associated with SIBO overlap with the cardinal symptoms of irritable bowel syndrome (IBS): abdominal pain; diarrhea, constipation, or both; bloating; and flatulence. SIBO can be diagnosed with several validated carbohydrate substrate (glucose or lactulose)–based breath tests that measure hydrogen and/or methane.
Hydrogen-positive breath tests suggest bacterial overgrowth, and methane-positive breath tests suggest small intestinal methanogen overgrowth. Methane is increasingly important and recognized, the AGA guideline says, though it creates a “nomenclature problem in the SIBO framework” because methanogens are not bacteria, the authors note.
In conventional practice, SIBO is typically treated with antibiotics such as rifaximin, and often with short-term dietary modification as well. Integrative medicine typically considers the use of supplements and botanicals in addition to or instead of antibiotics, as well as dietary change and increasingly, a close look at SIBO risk factors to prevent recurrence, Dr. Sivamani said. (His research unit is currently studying the use of herbal protocols as an alternative to antibiotics in patients with SIBO and dermatologic conditions.)
During a presentation on rosacea at the meeting, Neal Bhatia, MD, director of clinical dermatology at Therapeutics Clinical Research, a dermatology treatment and research center in San Diego, said that currently available breath tests for SIBO “are very interesting tools for understanding what may be happening in the gut” and that the “rifaximin data are good.”
He referred to a study reported in the Journal of the American Academy of Dermatology showing that patients with rosacea were significantly more likely to have SIBO (41.7% of 48 patients vs. 5.0% of 40 controls; P < .001), and that 64.5% of rosacea patients who completed treatment with rifaximin had remission of rosacea at a 3-year follow-up.
An earlier crossover study is also notable, he said. This study enrolled 113 consecutive patients with rosacea and 60 age- and sex-matched controls, and randomized those with SIBO (52 of the 113 with rosacea vs. 3 of the 60 controls) to rifaximin or placebo. Rosacea cleared in 20 of the 28 patients in the rifaximin group and greatly improved in 6 of the 28. Of 20 patients in the placebo group, rosacea remained unchanged in 18 and worsened in 2. When patients in the placebo group were switched to rifaximin, SIBO was eradicated in 17 of the 20, and rosacea completely resolved in 15 of those patients, Dr. Bhatia said.
In his view, it will take more time, greater awareness of the rosacea-SIBO link, and a willingness “to take chances” for more dermatologists to consider SIBO during rosacea care. “Breath tests are not something used in the [typical dermatology] clinic right now, but they may make their way in,” he said at the meeting.
In a follow-up interview, Dr. Bhatia emphasized that “it’s really a question of uptake, which always takes a while” and of willingness to “think through the disease from another angle ... especially in patients who are recalcitrant.”