Weight loss may reduce psoriasis severity in obese patients

London, U.K.: Weight loss can reduce the severity of psoriasis and psoriatic arthritis, and can also prevent the occurrence of psoriasis in obese individuals, a recent study published in the British Journal of Dermatology has found.

Psoriasis is an incurable skin condition affecting between two and four in every 1oo people in the Western world. It is characterized by uncomfortable, red scaly patches on the skin. It is associated with joint disease (psoriatic arthritis), obesity, heart attacks, and low mood. Previous studies have shown obesity to be associated with the worsening of psoriasis and losing weight to be beneficial for improving it.

Catherine Smith, Guy's and St Thomas’ NHS Foundation Trust, London, U.K., and colleagues aimed to determine if weight loss could reduce the severity and incidence of psoriasis or psoriatic arthritis (PsA) in obese individuals.

For the purpose, the researchers systematically searched scientific literature databases and identified 14 relevant studies that examined three key weight loss methods -- lifestyle changes (diet and exercise), weight loss medications, and weight loss surgery (e.g. gastric bypass).

Read Also: People with abdominal adiposity at increased risk of psoriasis

Key findings of the study include:

• Meta‐analysis of six randomized control trials (RCTs) confirmed that weight loss following lifestyle interventions (diet or physical activity) improves psoriasis compared with control [mean change in Psoriasis Area and Severity Index −2·59].


• One RCT demonstrated a greater likelihood of achieving minimal PsA activity following diet‐induced weight loss (odds ratio 4·20).


• Three studies of pharmacological treatments reported conflicting results, and no RCTs of bariatric surgery were identified.


• Two cohort studies suggested that bariatric surgery, particularly gastric bypass, reduces the risk of developing psoriasis (hazard ratio 0·52).

"These limited data support the role of proactive screening and treatment of obesity in patients with psoriasis and PsA, and highlight obesity as an important modifiable risk factor in the development of psoriasis. As obesity is an independent risk factor for other long-term conditions associated with psoriasis such as cardiovascular disease, weight loss also holds the promise of reducing overall extracutaneous morbidity. Achieving a healthy weight is thus a key treatment goal in psoriasis," wrote the authors.

Key takeaways from the study:

• Weight loss following lifestyle interventions (diet and physical activity) produces small but significant improvements in psoriasis and PsA in obese individuals.


• Despite bariatric surgery being the most effective weight loss intervention, there is a paucity of data on its role in the management of psoriasis and PsA.


• Weight loss following bariatric surgery, and in particular gastric bypass surgery, can prevent the development of psoriasis in obese individuals.


• Clinicians are encouraged to screen proactively for obesity in individuals with psoriasis and offer access to lifestyle, pharmacological and surgical weight loss interventions alongside conventional skin-focused treatments.

The study, "Weight loss in psoriasis and psoriatic arthritis," is published in the British Journal of Dermatology.

DOI: https://doi.org/10.1111/bjd.17741