Obesity and dermatological disease

Dr. Johnny Chun Yin CHAN - Council member, HKOS

Obesity is traditionally linked to various skin conditions. Acanthosis nigricans and acrochordons (skin tags) are common cutaneous manifestations associated with metabolic syndrome and obesity. Obesity is also known to increase the prevalence of various cutaneous infections including bacterial (furuncles, pyogenic folliculitis, erythrasma) and fungal (tinea, candidiasis) origins. Interestingly, obesity has been lately proven to be associated with psoriasis and its severity.

Psoriasis is a chronic, systemic, immune-mediated inflammatory disease, which affects the skin and joints. 1 It is a common condition that occurs in around 2% of the western population. The prevalence of psoriasis is lower in Asian races and was estimated to be 0.3% in our locality. 2 The disease has no sex predilection and can emerge at any time in life. Psoriasis is epidemiologically linked to a number of cardiovascular risk factors including obesity, smoking, hypertension, diabetes,
dyslipidemia and metabolic syndrome.

In recent decade, multiple studies had demonstrated higher prevalence of obesity in psoriatic patients. A meta-analysis on 16 observational studies published between 1980 and 2012 concluded an odds ratio (OR) of 1.66 (95% CI 1.46-1.89) for obesity in psoriatic patients when comparing to the control group. 3 Moreover, a positive correlation was established between obesity and severity of psoriasis. The reported increase in the prevalence rates of obesity (compared to normal controls) were 14%, 34% and 66% in patients with mild (≤ 2% body surface area [BSA]), moderate (3-10% BSA) and severe psoriasis (> 10% BSA) respectively. 4 A recent prospective, randomized-controlled trial of 60 overweight psoriatic patients has demonstrated a trend towards clinical improvement and a significant improvement in the quality of life with a weight reduction program. 5

We believe the Hong Kong Obesity Society will establish a solid platform in broadening our knowledge in the relationship between skin diseases and the problem of overweight. It will also serve the role in gathering local patient data and enhancing communication among local experts in the field.

References 1. Raychaudhuri SP, Farber EM. The prevalence of psoriasis in the world. J Eur Acad Dermatol Venereol 2001; 15: 16–17.
                   2. Farber EM, Nail L. Epidemiology: natural history and genetics. In: Roenigk HR Jr, Maibach HI. Psoriasis, 3rd edn. Marcel Dekker, New York, 1998: 107–157.

                   3. Armstrong AW, Harskamp CT, Armstrong EJ. The association between psoriasis and obesity: a systematic review and meta-analysis of observational studies. Nutr Diabetes. 2012;2:e54.
                   4. Langan SM, Seminara NM, Shin DB, Troxel AB, Kimmel SE, Mehta NN, Margolis DJ, Gelfand JM. Prevalence of metabolic
syndrome in patients with psoriasis: a population based study in the United Kingdom. J Invest Dermatol. 2012;132 (3 Pt 1):556.       

                   5. Jensen P, Zachariae C, Christensen R, Geiker NR, Schaadt BK, Stender S, Hansen PR, Astrup A, Skov L. Effect of weight loss on the severity of psoriasis: a randomized clinical study. JAMA Dermatol. 2013 Jul;149(7):795-801.