Weight loss in patients with psoriatic disease should be approached with skillful communication and a holistic, individualized — and often interdisciplinary — approach to evaluation and treatment that includes coverage of metabolic health, the gut microbiome, and sources of inflammation.

This was a key message delivered by dermatologists during several presentations addressing psoriasis and obesity at the 2025 Integrative Dermatology Symposium (IDS). The dermatologists each said they sometimes prescribe newer weight-loss drugs, depending on the patient’s needs and comorbidities. However, as did an obesity medicine specialist who also spoke at the meeting, they emphasized that lifestyle modification is a critical foundation of weight loss even when medications are used.

“Initiating discussions about obesity isn’t something we were doing 5-10 years ago, but it’s starting to pervade and it’s really important to try to get more comfort with this,” said Daniel C. Butler, MD, associate professor of dermatology and director of the inflammatory and aging skin research program, at College of Medicine Tucson, The University of Arizona, where the IDS meeting was held.

Obesity is a chronic disease, and dermatologists are experienced managing chronic conditions, skilled in employing multi-modal approaches to treatment, educating, personalizing care, and providing “continuous coaching” and follow-up, he said.

Moreover, understanding of the benefits of weight loss, including benefits in patients with psoriatic disease, “has grown exponentially in the last several years, so we can add [a lot more] to the conversation than we could years ago,” Butler said at the meeting.

Lifestyle Changes, Medications: Effects on Weight and Skin

The link between psoriasis and obesity has been well documented, with multiple studies documenting a rising risk for psoriasis — and increasing psoriasis severity — as BMI increases, as well as a greater prevalence of obesity in patients with psoriatic disease than without, and inflammatory states that manifest in both conditions and work bidirectionally.

This interconnectedness — and the association of psoriasis with metabolic syndrome, diabetes, hypertension, and cardiovascular disease as well — underpins the joint American Academy of Dermatology-National Psoriasis Foundation (NPF) guidelines issued in 2019 that recommend all patients with psoriatic disease be screened annually for obesity and assessed for cardiometabolic risk.

Evidence suggests that a BMI > 30 plays a role in patients’ abilities to achieve the full therapeutic effect of psoriasis therapy, said Jennifer Soung, MD, director of clinical research at Southern California Dermatology, Santa Ana, California, noting this is most relevant for first-generation biologics such as secukinumab.

And evidence is strong and growing that treating obesity — achieving even a 5%-10% weight loss — results in improvements in insulin sensitivity, blood glucose, risk markers for thrombosis, and endothelial function, as well as the severity of psoriatic disease and response to therapy, said Benjamin Ungar, MD, of the Department of Dermatology at Icahn School of Medicine at Mount Sinai in New York City.

“Even marginal weight loss is accompanied by a greater proportion of visceral adipose tissue weight loss,” he explained. “We know that psoriasis produces pro-inflammatory cytokines — IL-17 [interleukin-17], TNF-alpha, IL-23 — which promote adipose tissue inflammation, but adipose tissue itself is an active producer as well [of these cytokines]. There’s a loop that produces a state of systemic inflammation.”

The impact of weight loss on psoriasis has been documented with various weight loss modalities. Weight reduction achieved through a hypocaloric diet, for instance, has been shown to reduce psoriasis severity and was recommended as an adjunctive intervention to standard psoriasis therapies in dietary recommendations for adults with psoriasis or psoriatic arthritis published in 2018 from the NPF, Soung said.

In a 2015 systematic review and meta-analysis cited at the meeting by Raja Sivamani, MD, an integrative dermatologist at the Pacific Skin Institute in Sacramento, California, weight loss resulting from lifestyle intervention (diet and/or exercise) was associated with an almost threefold likelihood of achieving a 75% reduction in the Psoriasis Area Severity Index (PASI) score.

More evidence may come from an ongoing study in Germany — the METABOLyx randomized controlled trial — that is evaluating the combination of a lifestyle intervention program (weight reduction ≥ 5%, increase in physical activity, increase in fiber intake, and reduction in dietary fat) and secukinumab in patients with moderate-to-severe plaque psoriasis and metabolic syndrome, Soung noted.

Typically, multicomponent lifestyle interventions (“eat less, move more”) result in a loss of only 2%-5% of body weight, said endocrinologist and obesity medicine specialist Jaime Almandoz, MD, MBA, referring to an obesity treatment pyramid published in a 2021 report.

Prescriptive nutritional interventions such as specific diets have been shown in studies to result in weight loss of 5%-10%, but as with lifestyle interventions, the losses are often “transient,” he said at the meeting.

The use of pharmacotherapy increases the reduction further. In the recently published head-to-head SURMOUNT-5 trial results, treatment with the second-generation incretin obesity medications, semaglutide and tirzepatide, led to 72-week mean weight reductions of 13.7% and 20.2%, respectively, “And there’s a lot in the pipeline,” Almandoz said.

In medical practice in general, he advised that anti-obesity medications should be considered in several scenarios: For patients who have difficulties initiating or maintaining lifestyle modification, those who regain weight on lifestyle modification, and those who have weight-related conditions “that we know can be helped with these drugs.” Lifestyle modification is “foundational for health,” however, and should always be part of plan, he emphasized.

Medications should be selected “not just [based] on potential efficacy but on potential risks” as well, added Almandoz, professor of internal medicine and medical director of the Weight Wellness Program at UT Southwestern Medical Center, Dallas. “It feels like we’re in a GLP-or-bust environment right now, but there are [a variety] of effective treatments that can be used to help people achieve a healthier weight.”

Regarding the effect of GLP-1 receptor agonists (RAs) on psoriasis, Soung cited a 2022 systematic review and meta-analysis of the first-generation GLP-1 RA liraglutide in which patients with type 2 diabetes and plaque psoriasis showed significantly lower PASI scores after treatment. Importantly, Soung said, the research shows that liraglutide “can reduce the expression of IL-17, IL-23, and TNF-alpha pro-inflammatory cytokines” involved in psoriasis and obesity pathogenesis.

And in a case report of a patient with severe psoriasis and type 2 diabetes, she noted, 12 weeks of therapy with semaglutide led to significant decreases in BMI (from 47 to 40) and PASI score (from 32 to 8). After 10 months, the patient’s BMI was 38 and PASI score was 2.6. (The patient had been previously treated with topical therapy and adalimumab without success, according to the report).

More research is underway, Soung said, including two phase 3 randomized open-label trials, TOGETHER-PsO and TOGETHER-PsA, comparing concomitant therapy with tirzepatide and ixekizumab and the biologic alone in patients who have psoriatic disease and overweight or obesity.

Beyond Medications

In working with patients on weight loss “we have to look at inflammation from a bunch of angles,” Ungar said at the meeting, “Various metabolic factors play a role in promoting inflammation, for instance, and we know there’s a role for the microbiome and dysbiosis.”

A clinical case presented by Sivamani at the meeting illustrates such considerations and an integrative approach to weight loss. His patient had long-standing, widespread plaque psoriasis that was previously treated with topical steroids, and no joint pain or enthesitis on examination. His BMI was 29.2 and he was physically inactive. Unhappy with his weight, he had tried different diets, including a gluten-free diet, and was favoring a carnivore diet.

Gut microbiome testing with the gastrointestinal-microbial assay plus showed a low level of Akkermansia muciniphila bacteria — which is “really important for short-chain fatty acid production” — and low levels of commensal/Keystone bacteria, Sivamani said. Candida, he noted, appeared “not to be involved.”

The patient’s omega-3 index was very low, indicating a higher inflammatory state, and his homeostatic model assessment for insulin resistance (HOMA-IR) score, calculated from fasting blood glucose and fasting insulin levels, was elevated. Additionally, levels of small dense and large buoyant low-density lipoprotein, and of apolipoprotein B, were elevated, suggesting increased cardiovascular risk. Liver function tests were normal.

To evaluate the value of another trial of a gluten-free diet, Sivamani also tested anti-gliadin antibodies. In research from Europe, patients with psoriasis who had both immunoglobulin (Ig)A and IgG antibodies to gliadin had a mean 80% improvement in PASI score after following a gluten-free diet for 3 months, and those with single-positive results had a 71%-75% PASI score improvement, he explained. Patients who tested negative — as Sivamani’s patient did — had no improvement in PASI score from the diet.

To address insulin resistance and promote weight loss, the patient’s treatment protocol included intermittent fasting/time-restricted eating in which he was advised to have breakfast and lunch only, the consumption of protein prior to carbohydrates, and brisk post-dinner walks when dinner was consumed. “It’s harder to lose weight with higher circulating insulin,” Sivamani emphasized.

To address gut dysbiosis, Sivamani prescribed an increase in fiber intake and a probiotic supplement, GLP-1 probiotic pro, which contains A muciniphila and two other bacterial strains believed to increase GLP-1 production in the gut. And to address systemic inflammation, he prescribed 2000 mg DHA (algal) daily because the patient wanted to avoid fish-based sources.

Biologics were discussed, but the patient “ultimately chose deucravacitinib because he wanted something oral and he wanted to do it with phototherapy,” which was administered twice weekly, Sivamani said.

After 4 months, the patient’s BMI had dropped to 25.4 (from 29.2), HOMA-IR score dropped to 1.8 (from 2.6), and skin lesions were clear. The patient stopped intermittent fasting after 2 months as he lost weight and now eats more protein-heavy meals in the evening, including tofu. He engages in weight training and takes brisk walks several nights a week.

“What was really important,” Sivamani said, “was he changed his trajectory of how he thought about his health. He felt like ‘I have a say in how I’m treating myself.’”

Initiating Discussions, Collaboration

To introduce weight into a conversation, Sivamani advises asking a patient about diet and nutrition “because it’s a safe space.” Asking patients how they think nutrition is affecting their health, for instance, often prompts them to bring up weight on their own. A mention of insulin resistance may similarly prompt a patient-initiated discussion about weight.

If a patient does not bring up weight on their own, “revisit it at a future appointment…possibly by listing lifestyle factors that can influence [psoriasis], including weight as one of them,” Sivamani said. “I’ve seen over and over again that you can’t predict if someone will be sensitive or not,” he said. “It’s a big deal because it can ruin rapport early in a conversation if they think you’re shaming them, so to speak.”

As Butler sees it, asking for permission to discuss weight is “part of building equity” for a trusting and long-term relationship. Examples of questions include: Can we discuss your weight as part of your overall health? Are you comfortable discussing your weight with me? Can we touch on the subject of weight?

Additionally, asking patients about their weight-specific history — for example, “What has your weight journey been like?” — helps “build an empathetic rapport and can provide a runway for discussion” and shared decision-making, he said.

Continuous follow-up and support are “huge” with weight loss, Butler emphasized, noting that patients need to be assured of “the ability to recover even if there are steps backwards.” Like others at the meeting, he also encouraged dermatologists to “grow in [their] collaborative approach with other providers.”

Successful weight loss care is often multi-disciplinary, and “I think we may be ping-ponging too much with primary care,” Butler said. “We can also be the ones who initiate those discussions with dieticians and surgeons [and others]. …We have a license with patients that many other specialists don’t have.”

Sivamani disclosed receiving consulting fees (eg, advisory board) and speakers’ bureau participation for Sanofi, Pfizer, Lilly, Bristol Myers Squibb, and several other companies. Butler disclosed being a consultant/advisor/speaker for Galderma, Leo, and Sanofi. Ungar reported being a consultant/advisor/speaker for AbbVie, Lilly, Pfizer, Botanix, and other companies. Almandoz disclosed being a consultant/advisor/speaker for AbbVie, Amgen, Lilly, Novo Nordisk, and other companies. Soung disclosed advisory board/consultant work with Amgen, AbbVie, Eli Lilly, Novartis, and other companies.