Dermatogeriatrics: a case for developing a new dermatology subspecialty

Key words::

• geriatric dermatology
• psoriasis
• elderly
• immunosuppression

Rising standard of living and rapid advancement in medicine have led to a population that is living longer and longer. Life expectancy for a male born today in the United States is 75.4 years and for a female born today is 80.4 years, which is approximately 30 years more for men and 32 years more for women than at the turn of the last century when the life expectancy for men was only 46.3 and for women was 48.3 (1). A remarkable 63% increase in life expectancy for men and 66% increase for women occurred over the last century in the United States. In countries such as Italy, Greece, Sweden, and Japan, life expectancy is even longer (2). For instance, in Japan, the life expectancy today is 78.7 years for males and 85.6 years for females, which is 36 years longer for men and 41 years longer for women since 1900 (3). This means a remarkable 84% increase in life expectancy in men and 92% increase in women occurred in Japan. For dermatologists, this means that a growing number of patients will comprise of an older population – the elderly.

The U.S. census in 2000 reported that 13% of the population was 65 years of age and older (4). By 2020, it is estimated that 25% of the U.S. population will be comprised of the elderly (5,6). Today, over 20% of the Japanese population is 65 years or older, while 18% to 20% of the populations in Germany, Greece, Italy, and Sweden are over 65 (3). Despite a population explosion in less developed countries, by the year 2050, fully 20% of the global population is expected to consist of those 65 years or older (5).

There are many age-related skin changes that make the care of the elderly more challenging compared to younger age groups. First, skin pathologies increase over time. This increase is a result of multiple physiological changes coupled with cumulative insults of environmental exposure. Physiologically, the epidermo-dermal junction flattens with age. The epidermis has slower cell turnover and is thinner in the elderly compared to younger cohorts, which increase susceptibility for trauma and poor wound repair. Sebaceous and eccrine glands decline in function, resulting in xerosis and pruritus. Increased pruritus also occurs due to neurodegenerative changes, diminished epidermal barrier, and reduced capacity for barrier repair (7). Moreover, there are many other factors such as cumulative damages from UV exposure on the skin, diminished hair density, reduced vascular flow, sweating, and subcutaneous fat, decreased fibroblasts, elastin, melanocytes, mast cells, and Langerhans cells, and even slower nail growth, all contributing to dermatological problems in the elderly (8). Due to these changes, a number of chronic dermatologic conditions become more prominent in the geriatric population including nummular eczema, xerotic eczema, psoriasis, bullous pemphigoid, chronic venous insufficiency, ecchymosis, and pressure ulcers, as well as the entire spectrum of skin neoplasms, to name a few.

Second, patients experience age-related immunosuppression, making them more vulnerable to cancer and infection. Cancer is the second most common cause of death in the elderly after cardiovascular disease. With regard to infection, the elderly are more susceptible to herpes zoster, Candidal infection, staphylococcal impetigo, streptococcal cellulitis, and even Norwegian scabies infestation (3). Therefore, the concept of age-related immunosuppression is very important for dermatologists to understand. For chronic illnesses such as psoriasis and psoriatic arthritis, the use of immunosuppressants is the mainstay, including biologic therapies such as adalimumab, ustekinumab, infliximab, alefacept, and etanercept, as well as non-biologic options such as cyclosporine and methotrexate. In addition, virtually all new agents being developed for psoriasis are immunosuppressants. This is a serious concern because the elderly are already immunosuppressed from the aging process.

Third, the presence of comorbidities is also a major concern for the elderly. Common comorbidities include metabolic syndrome, hypertension, dementia, renal insufficiency, diabetes mellitus, poor hepatic function, and cancer. Care must be taken to ensure that dermatologic medications do not aggravate these diseases. Toxicities to the cardiovascular, renal, neurologic, and hepatic systems are likely to be particularly problematic with the elderly. Cyclosporine, for instance, can elevate blood pressure and decrease renal function, while methotrexate can cause bone marrow and hepatic toxicity. The latest biologic agent considered for FDA approval for psoriasis, namely, briakinumab, has also been withdrawn from drug development for possible cardiovascular risk. In addition to pharmacologic consideration, comorbidities can also manifest as cutaneous disease. Diabetes mellitus affects approximately 27% of older adults and can cause diabetic xanthomas, acanthosis nigricans, and ulcers in addition to causing endocrine abnormality (9). Alterations in thyroid hormone are also more frequently associated with aging. Hyperthyroidism can manifest as pretibial myxedema while hypothyroidism causes thinning of the eyebrows and coarse, brittle hair.

Fourth, there are physical, logistical, and psychological limitations unique to the elderly. Elderly patients often have reduced mobility. From a medical perspective, phototherapy is a systemically safer method for treatment of elderly patients with eczema and psoriasis. However, the ability to stand in the boxes is a prerequisite for phototherapy, which is a frequent barrier to this treatment for the elderly. Some geriatric patients are also not able to transport themselves to the clinic for phototherapy in the first place because of hip impairment, arthritis, or lack of transportation. Even taking public transportation can be a challenge due to limited endurance or cognitive disability. In addition, isolation, depression, and anxiety, which are commonly experienced by the elderly make it more difficult for geriatric patients to access care (10). One study documented that elderly women with psoriasis experience a worse quality of life compared to younger counterparts (10).

At present, there is no integrated subspecialty within dermatology that focuses specifically on the numerous and distinct issues critical to the geriatric population. As a result, these varied immunologic, physiologic, logistical, and psychosocial issues of the elderly are being managed in a fragmented way by different practitioners of dermatology. Furthermore, there is essentially no research in dermatology specifically targeting the geriatric population. Therefore, there is very little known about the risks of systemic therapies on this population. Healthy elderly patients may tolerate certain systemic agents well compared to less healthy patients in their age group, but dermatologists may be afraid to treat either of them with these medications because so little is known about the risks of these treatments in the elderly. In fact, even a dermatological consensus on who is “elderly” or “geriatric” has yet to be defined. Most of us do not consider 60 years old or even 55 years old as “middle age.” Are 55 or 60 year olds considered “elderly?” Are they “geriatric patients?” Even though 65 years of age conveniently reflects the threshold for Medicare in the United States, this may change due to federal deficits. In California, Governor Brown recently announced a proposal to raise the retirement age to 67. We cannot simply rely on preexisting, borrowed definitions from others to define this population for our specialty. Hence, we as a dermatology specialty need to define what makes sense for us as an appropriate threshold age for geriatrics in dermatology, considering physiological, immunological, and other factors relevant to our specialty.

As a consequence of the lack of focus on this age group in our specialty, there is practically no activity in facilitating a clinical discussion and formulating consensus for optimal elderly care. We cannot continue having these critical issues with this prominent age group managed in such a disjointed manner. A new subspecialty in dermatology is needed to systematically optimize the safety and efficacy of managing the elderly population.

The establishment of geriatric dermatology, “Dermatogeriatrics,” as a subspecialty of dermatology is essential for us to better understand and more effectively manage this growing population in the near future. We propose the goal of Dermatogeriatrics be to optimize care for geriatric patients by promoting education regarding the unique physiology, pathophysiology, and psychology of this population, by conducting research specifically targeting the elderly, and by facilitating the clinical discussion to develop guidelines and consensus for optimal dermatological care of the elderly.

Declaration of interest: Ms. Wong reports no conflicts of interest. Dr. Koo has the following conflicts of interest: Abbott, Amgen, Astellas, Janssen, Galderma, GalaxoSmithKline, Leo Pharma, Novartis, Pfizer, Photomedex, and Teikoku. The authors alone are responsible for the content and writing of the paper.