Our study protocol collected data from both patients and physicians to achieve multiple objectives concurrently. The results from the ‘patient arm’ of the study parallel known literature, demonstrating high rates of asteatosis affecting the geriatric population. Ageing leads to functional and structural alterations in the stratum corneum, which in turn causes skin to be more fragile, more prone to irritation, inflammation and infections.[9]
Our study found that 81.6% of geriatric patients who presented for chronic medical care had asteatosis, and that the odds of having asteatosis increased by 13.5% with every additional year of age. Despite this high prevalence of asteatosis, these patients often do not seek treatment in early stages as they are largely asymptomatic. The cumulative healthcare burden of asteatosis can become significant, as asteatosis is a precursor for developing symptomatic asteatotic eczema. A review of our in-house data registry of outpatients seen by the Division of Dermatology, NUH, indicated a total of 4985 outpatient first visits in the year 2019, of which 1157 encounters (23.2%) were by those 65 years and older. 444 (38.4%) of these 1157 encounters were for eczema, which is much higher in contrast to cutaneous malignancies (9.7%). Furthermore, the same in-house data registry of 1277 inpatient encounters (in the form of interdepartmental referrals or dermatology inpatients) seen by the Division of Dermatology, NUH within the year 2019 indicated 390 (30.5%) patients seen for eczema alone, of which 201 (15.7% of total inpatient encounters, 51.5% of all geriatric inpatient encounters) were geriatric patients with eczema. These inpatients tend to suffer from more severe forms of eczema (e.g. erythrodermic eczema), or complications of eczema, such as skin and soft tissue infections. This highlights the high burden of eczema of which asteatosis is a significant risk factor, especially in the geriatric population.
While our data suggests that the incidence of urticarial disorders increases with age, the in-house data registry indicates only 3.0% of first visit outpatient encounters and 104 (8.1%) of 1277 inpatient encounters being due to urticarial disorders. Only 33 (2.6%) inpatients were of the geriatric age group. We postulate that this contrasted greatly with the eczema data, as antihistamines are commonly prescribed in the primary care setting, which provide immediate and dramatic symptom relief for urticaria. Urticaria often presents in the acute form, which portends rapid resolution. This in turn reduces the number of patients who request for referrals to see specialists. In contrast, eczema is caused by a complex interplay of intrinsic and extrinsic factors which may not respond as readily to first-line therapy. Patients may be more inclined to perceive treatment failure and hence request for specialist review.
The positive correlation between the use of topical preparations and having eczema and inflammatory dermatoses likely represents an association more than a causation. As our questionnaire did not further sub-classify the nature of the topicals used, it raises a possibility of a bidirectional relationship between eczema and the use of topicals. We purport that the elderly with eczema were more likely to be symptomatic, and hence would have self-attempted topical therapy. However, we recognise that traditional salves or ointments containing salicylates, camphor, essential oils or other contactants, which are readily obtainable over the counter in Singapore, may cause contact dermatitis, accounting for eczema in these patients as well. The cross-sectional nature of this study limits elucidation of this aspect. Future local studies can aim to better characterise the exact nature of topical usage in the average Singaporean elderly.
The methodology of examining “skin-well” elderly is a strength, compared to most existing Singaporean studies which drew data retrospectively from tertiary care institutions and national registries.[4, 6] Our patient population more accurately represents the average elderly Singaporean population at large, and as a result, reduces surveillance bias and an overrepresentation of dermatoses.
The finding of approximately 20% of clinical encounters reported by our surveyed PCPs as being related to dermatological disorders is consistent with published prevalence from England and Wales,[7] suggesting that the high dermatological disease burden transcends communities of all skin types and locations. However, Singapore possesses unique geographic factors and healthcare models which in turn shape and alter the behaviour of the average patient. As a small and densely populated city-state, Singapore has tertiary hospitals within close proximity to all residential areas of the country; most residents have access to these hospitals within a 30-minute commute. This greatly lowers the physical distance barrier to specialist visits, which may be an important deterrent in other larger nations. Furthermore, the Singaporean healthcare model historically has strong specialist presence in the holistic care of an individual. This translates to patients having a low threshold to seek specialist review, and may explain the finding of how our surveyed physicians reported 50% of their first visit referrals being done solely due to the patient's own request.
Malignant and benign cutaneous lesions, psoriasis and pigmentary disorders were reported by PCPs as being referred at a higher rate on the first visit. A qualitative study in the United Kingdom indicated that current routine practice for psoriasis management in primary care was mismatched with the expressed needs of patients.[10] Patients perceived PCPs to lack confidence in the assessment and management of psoriasis, and both patients and physicians felt lacking in knowledge about the condition. A Spanish study (2012) looking at the reasons for primary care referral to dermatology and diagnostic agreement between PCPs and dermatologists analysed data from 755 patients with 882 first visit encounters in a span of 3 months; the most common diagnoses included benign cutaneous conditions such as seborrhoeic keratoses and melanocytic naevi.[11] Primary care diagnoses for skin tumours was reported to have a sensitivity of 22.4%, and a specificity of 94.7%; this meant that PCPs were better qualified to rule out a given skin condition (high specificity) than to establish an accurate clinical diagnosis (poor sensitivity). This may mirror the situation in Singapore as well, where PCPs more readily refer cutaneous lesions to rule out malignancy.
A limitation of the ‘patient arm’ of the study was the small sample size. Oh et al published a large scale prospective study of 63,257 men and women who were 45 to 74 years old at recruitment from 1993 to 1998,[12] which demonstrated that caffeine intake reduced non-melanoma skin cancer risk in a dose-dependent manner. We did not find a significant relationship between skin cancers and caffeine intake, as well as known risk factors of sun exposure or smoking, in our own data set. This is mostly likely driven by an underpowered study to pick up rarer diagnoses.
We recognise potential selection bias in our patient recruitment process, where patients with self-perceived skin issues may have been more forthcoming with volunteering for recruitment and examination. To minimise this bias, we propose future studies involving PCPs performing full skin examinations as part of their regular chronic health checks for asymptomatic elderly patients.
The 2-week recall period for physicians was chosen to allow sufficient duration for catchment of rarer dermatoses, but was short enough for cases encountered to be fresh in their memories. Nonetheless, we recognise this arbitrarily chosen duration may be subject to recall bias, where physicians may misrepresent numbers based on their most recent or most memorable dermatological encounters. Future studies can attempt to prospectively measure actual number of first visits and specialists’ referrals from polyclinics for dermatological conditions in geriatric patients.
In the United Kingdom, there has been recognition of insufficient dermatological exposure in medical school, where students receive no more than 6 days training in dermatology, but yet a quarter of primary care appointments concern the skin.[13] A recent United Kingdom cross-sectional study of 318 video-recorded consultations identified 14.2% of consults pertaining to 1 or more dermatological problems, of which there was low shared decision making and infrequent self-management advice given to the patients. A striking finding of the study highlighted that while 84.3% of skin problems were not referred to secondary care, 32.6% of those not referred were seen again in primary care within 12 weeks, of which 35.7% follow-up appointments were unplanned.[14] This study demonstrated the challenges of dermatological care in the primary care setting, and the authors postulated that the complexities of juggling multiple presenting complaints within time-limited consultations led to less than ideal counselling and follow-up accorded to the dermatological conditions. A qualitative study (2007) carried out in the United Kingdom compared the effectiveness of a “General Practitioner with Special Interests” (GPSI) dermatology service with standard consultant-led dermatology outpatient care.[15] The study surmised that GPSI services were acceptable to the majority, but there was likely to be a group of patients with longstanding, though clinically non-urgent, conditions for whom the service would not be acceptable.