Several skin presentations in obese patients are associated with the presence of excess skin while others are associated with the pathophysiology of obesity. Dermatologists should have a conversation about weight loss with obese patients.
Obesity is a public health epidemic associated with cardiovascular disease, stroke, and diabetes, but the presence of obesity is also linked to numerous dermatological presentations related to the increased amount of skin and to the pathophysiology of obesity.
"Obesity can lead to skin tags," explains Benjamin Barankin M.D., F.R.C.P.C., a dermatologist based in Toronto, Ontario, Canada and Co-Founder of the Toronto Dermatology Centre. "People who are obese have more skin tags, in more areas, and they are bigger skin tags. Stretch marks also appear more often in obese individuals."
Dr. Barankin notes another condition linked to obesity is acanthosis nigricans, a thickening and darkening of the skin in sites like the armpits, groin, neck and other intertriginous areas. General thickening of the skin and darkening of the elbows and knees is common in larger patients compared to patients of normal weight, Dr. Barankin adds.
Infections, both bacterial and fungal, are also more common in obese than non-obese patients, he says.
A condition like hidradenitis suppurativa is associated with the carriage of excess weight, as is chronic plaque psoriasis, and shedding excess weight is associated with improvements in those conditions, a point that creates an opportunity for dermatologists to communicate with their patients about how they can influence their disease course through their diet and activity, Dr. Barankin explains.
"We are always looking for reasons for people to adopt healthy lifestyle choices and behaviours," Dr. Barankin says, stressing obesity exacerbates psoriasis. "If a patient is bothered by his or her psoriasis, here is another reason to take steps like see a dietician, lose weight, and exercise more."
Indeed, there is strong relationship between obesity and psoriasis, likely based on shared inflammatory pathways.
"There is clear evidence linking obesity and psoriasis," Melissa Peck Piliang M.D., a dermatologist at the Cleveland Clinic in Cleveland, Ohio, told MedPage Today. "Patients who are obese are at higher risk of developing psoriasis, and they have more treatment-resistant psoriasis."
Dr. Piliang noted that cytokines elevated in patients who are obese are the same ones that lead to psoriasis and psoriatic arthritis.
"Obesity complicates treatment of psoriasis," Dr. Pilian told Dermatology Times. "Many biologic medications are less effective in obese patients and require a higher dose. The higher dosing regimen can significantly increase the cost of treatment."
Dr. Barankin agrees that the efficacy of psoriasis therapies is often compromised in obese patients.
"You have to use a larger dose of drug to be distributed to a larger area," Dr. Barankin explains. "Some drugs, however, come in a fixed dose, and you can't increase the dose. If you look at biologics such as etanercept or adalimumab, they may not work as well if they have to be distributed in a larger area."
If patients lose weight, "the drug needs to be distributed to a smaller volume," so patients will do often better with treatment, Dr. Barankin adds.
At the recent meeting of the Canadian Wound Care Association, clinicians discussed issues around bariatric skin and wound care.
"Bariatric skin often heals poorly," explains Laurie Parsons M.D., F.R.C.P.C., Medical Director of the Southern Alberta Wound Clinic in Calgary, Alberta, Canada, and assistant clinical professor of dermatology at the University of Calgary in Calgary, Alberta, Canada. "There are more inflammatory cells in adipose tissue, and these cells contribute to stiffening of connective tissue."
As a result, Dr. Parsons explains there is diminished perfusion of oxygen from vessel to the tissue, making tissue relatively hypoxic.
"If the tissue is hypoxic, it takes longer for an injury to heal, and it heals poorly," Dr. Parsons notes. "If you have tissue that is not well oxygenated, you are certainly more prone to infection. Macrophages need oxygen to kill bacteria. Consequently, when they (obese patients) get their wounds, they are harder to heal."
The frequent co-morbid presentation of diabetes with obesity impairs the wound healing process, Dr. Parsons adds.
Another consideration are the skin folds in the moist, intertriginous zones of obese patients, which are an ideal setting for yeasts like Candida, with lesions developing under the breasts, under abdominal folds, and in inguinal areas, Dr. Parsons says.
"Treating yeast infections in the skin folds is important," Dr. Parsons says. "We need to use non talcum power to absorb moisture and make sure that skin folds are cleansed properly on a daily basis, and this is particularly true in the morbidly obese patients where moisture-associated skin damage can result in skin ulcers."
The conversation about weight loss is one that a dermatologist should try to have with an obese patient, according to Dr. Parsons.
"The cardiologist will tell patients obesity is bad for the heart, and an orthopedist will tell patients that obesity is bad for the knees," Dr. Parsons says. "They (patients) have to understand the repercussions (of obesity) to their skin health."
Drs. Barankin, Piliang, and Parsons all had no relevant disclosures.