Seborrheic dermatitis, increased sebum excretion, and Parkinson's disease: a survey of (im)possible links

A fast and non-invasive artificial intelligence olfactory-like system that aids diagnosis of Parkinson's disease

BACKGROUND AND PURPOSE

Several previous studies have shown that skin sebum analysis can be used to diagnose Parkinson's disease (PD). The aim of this study was to develop a portable artificial intelligence olfactory-like (AIO) system based on gas chromatographic analysis of the volatile organic compounds (VOCs) in patient sebum and explore its application value in the diagnosis of PD.

METHODS

The skin VOCs from 121 PD patients and 129 healthy controls were analyzed using the AIO system and three classic machine learning models were established, including the gradient boosting decision tree (GBDT), random forest and extreme gradient boosting, to assist the diagnosis of PD and predict its severity.

RESULTS

A 20-s time series of AIO system data were collected from each participant. The VOC peaks at a large number of time points roughly concentrated around 5-12 s were significantly higher in PD subjects. The gradient boosting decision tree model showed the best ability to differentiate PD from healthy controls, yielding a sensitivity of 83.33% and a specificity of 84.00%. However, the system failed to predict PD progression scored by Hoehn-Yahr stage.

CONCLUSIONS

This study provides a fast, low-cost and non-invasive method to distinguish PD patients from healthy controls. Furthermore, our study also indicates abnormal sebaceous gland secretion in PD patients, providing new evidence for exploring the pathogenesis of PD.

Microorganisms associated with increased risk of Parkinson's disease

Parkinson's disease (PD) is a neurodegenerative disorder that affects more than 7 million people worldwide. Its aetiology is unknown, although the hypothesis of a genetic susceptibility to environmental agents is accepted. These environmental agents include fungi, bacteria, and viruses. Three microorganisms are directly associated with a significantly increased risk of developing Parkinson's disease: the fungal genus Malassezia, the bacterium Helicobacter pylori, and the hepatitis C virus. If the host is vulnerable due to genetic susceptibility or immune weakness, these microorganisms can access and infect the nervous system, causing chronic neuroinflammation with neurodegeneration. Other microorganisms show an epidemiological association with the disease, including the influenza type A, Japanese encephalitis type B, St Louis, and West Nile viruses. These viruses can affect the nervous system, causing encephalitis, which can result in parkinsonism. This article reviews the role of all these microorganisms in Parkinson's disease.

The Psychosocial Impact of Chronic Facial Dermatoses in Adults

INTRODUCTION

Skin diseases have negative psychological and social consequences, especially when they are chronic and affect a visible area of the body, such as the face.

OBJECTIVES

The purpose of this study is to investigate and compare the psychosocial impact of three common chronic dermatoses of the face: acne, rosacea, and seborrheic dermatitis.

METHODS

The Dermatology Life Quality Index (DLQI), Hospital Anxiety and Depression Scale (HADS), and Social Appearance Anxiety Scale (SAAS) were used to compare acne, rosacea, and seborrheic dermatitis patients and healthy controls. The relationships between DLQI, HADS, and SAAS results were investigated, as well as their associations with disease duration and severity.

RESULTS

The study included 166 acne patients, 134 rosacea patients, 120 seborrheic dermatitis patients, and 124 controls. The patient groups had significantly higher DLQI, HADS, and SAAS scores than the control group. Rosacea patients had the highest DLQI and SAAS scores, as well as the highest anxiety prevalence. Patients with seborrheic dermatitis had the highest rate of depression. The DLQI, HADS, and SAAS results were moderately correlated with each other, but their relationship with disease duration and severity was insignificant or weak at best.

CONCLUSIONS

Chronic facial dermatoses have a detrimental impact on mood and quality of life. Although patients with acne, rosacea, and seborrheic dermatitis have distinct lesions, the outcomes in terms of quality of life, anxiety, and depression are largely similar. Furthermore, these patients report similar levels of social anxiety as a result of their overall appearance.

Artificial Intelligent Olfactory System for the Diagnosis of Parkinson's Disease

Background: Currently, Parkinson's disease (PD) diagnosis is mainly based on medical history and physical examination, and there is no objective and consistent basis. By the time of diagnosis, the disease would have progressed to the middle and late stages. Pilot studies have shown that a unique smell was present in the skin sebum of PD patients. This increases the possibility of a noninvasive diagnosis of PD using an odor profile. Methods: Fast gas chromatography (GC) combined with a surface acoustic wave sensor with embedded machine learning (ML) algorithms was proposed to establish an artificial intelligent olfactory (AIO) system for the diagnosis of Parkinson's through smell. Sebum samples of 43 PD patients and 44 healthy controls (HCs) from Fourth Affiliated Hospital of Zhejiang University School of Medicine, China, were smelled by the AIO system. Univariate and multivariate methods were used to identify the significant volatile organic compound (VOC) features in the chromatograms. ML algorithms, including support vector machine, random forest (RF), k nearest neighbor (KNN), AdaBoost (AB), and Naive Bayes (NB), were used to distinguish PD patients from HC based on the VOC peaks in the chromatograms of sebum samples. Results: VOC peaks with average retention times of 5.7, 6.0, and 10.6 s, respectively, corresponding to octanal, hexyl acetate, and perillic aldehyde, were significantly different in PD and HC. The accuracy of the classification based on the significant features was 70.8%. Based on the odor profile, the classification had the highest accuracy and F1 of the five models with 0.855 from NB and 0.846 from AB, respectively, in the process of model establishing. The highest specificity and sensitivity of the five classifiers were 91.6% from NB and 91.7% from RF and KNN, respectively, in the evaluating set. Conclusions: The proposed AIO system can be used to diagnose PD through the odor profile of sebum. Using the AIO system is helpful for the screening and diagnosis of PD and is conducive to further tracking and frequent monitoring of the PD treatment process.

Metabolomics of sebum reveals lipid dysregulation in Parkinson's disease

Parkinson's disease (PD) is a progressive neurodegenerative disorder, which is characterised by degeneration of distinct neuronal populations, including dopaminergic neurons of the substantia nigra. Here, we use a metabolomics profiling approach to identify changes to lipids in PD observed in sebum, a non-invasively available biofluid. We used liquid chromatography-mass spectrometry (LC-MS) to analyse 274 samples from participants (80 drug naïve PD, 138 medicated PD and 56 well matched control subjects) and detected metabolites that could predict PD phenotype. Pathway enrichment analysis shows alterations in lipid metabolism related to the carnitine shuttle, sphingolipid metabolism, arachidonic acid metabolism and fatty acid biosynthesis. This study shows sebum can be used to identify potential biomarkers for PD.

Cerebrospinal fluid lactoperoxidase level is enhanced in idiopathic Parkinson's disease, and correlates with levodopa equivalent daily dose

Lactoperoxidase (LPO) is proposed to play a role in the pathogenesis of Parkinson's disease (PD). This enzyme has been reported to be enhanced in the cerebrospinal fluid (CSF) in parkinsonian patients. The objective was to look at the relationship of LPO in the CSF and serum with clinical features of idiopathic PD. LPO concentration was analyzed through ELISA techniques. Correlation of CSF or serum LPO and MDS-UPDRS, dopaminergic medication, and other clinical parameters was examined. The findings revealed that LPO concentration in the CSF, not serum, was found to be elevated in patients with PD relative to controls (p < 0.001). CSF LPO concentration negatively correlated with MDS-UPDRS part-IV score (p < .0001), a rating scale that allows evaluating motor complications. CSF LPO level inversely correlated with the dose intensity of the dopaminergic medication regimen, as evaluated with levodopa equivalent dose or LED (mg/day; p < .0001). LED value positively correlated with MDS-UPDRS part-IV score (p < .0001). To sum up, the findings indicate that CSF LPO is found to be elevated in the CSF of PD patients, and this enzyme holds promise as potential biomarker for diagnosis of PD. Increasing the dose intensity of the dopaminergic medication regimen attenuates the elevation in LPO levels in the CSF, and it facilitates the development of motor complications in patients. The pathophysiological mechanisms that seem to be responsible for LPO increase would include dopamine deficiency, oxidative stress, and less likely, microbial infection.

Parkinson's disease and skin

Parkinson's disease is associated with a variety of dermatologic disorders and the study of skin may provide insights into pathophysiological mechanisms underlying this common neurodegenerative disorder. Skin disorders in patients with Parkinson's disease can be divided into two major groups: 1) non-iatrogenic disorders, including melanoma, seborrheic dermatitis, sweating disorders, bullous pemphigoid, and rosacea, and 2) iatrogenic disorders related either to systemic side effects of antiparkinsonian medications or to the delivery system of antiparkinsonian therapy, including primarily carbidopa/levodopa, rotigotine and other dopamine agonists, amantadine, catechol-O-methyl transferase inhibitors, subcutaneous apomorphine, levodopa/carbidopa intestinal gel, and deep brain stimulation. Recent advances in our understanding of the role of α-synuclein in peripheral tissues, including the skin, and research based on induced pluripotent stem cells derived from skin fibroblasts have made skin an important target for the study of Parkinson's disease pathogenesis, drug discovery, novel stem cell therapies, and diagnostics.

Microorganisms that are related with increased risk for Parkinson's disease

Parkinson's disease is a neurodegenerative disorder that affects more than 7 million people worldwide. Its aetiology is unknown, although the hypothesis of a genetic susceptibility to environmental agents is accepted. These environmental agents include fungi, bacteria, and viruses. Three microorganisms are directly associated with a significantly increased risk of developing Parkinson's disease: the fungal genus Malassezia, the bacterium Helicobacter pylori, and the hepatitis C virus. If the host is vulnerable due to genetic susceptibility or immune weakness, these microorganisms can access and infect the nervous system, causing chronic neuroinflammation with neurodegeneration. Other microorganisms show an epidemiological association with the disease, including the influenza type A, Japanese encephalitis type B, St Louis, and West Nile viruses. These viruses can affect the nervous system, causing encephalitis, which can result in parkinsonism. This article reviews the role of all these microorganisms in Parkinson's disease.

Malassezia and Parkinson's Disease

Parkinson's disease (PD) is a common debilitating neurodegenerative disease caused by a loss of dopamine neurons in the substantia nigra within the central nervous system (CNS). The process leading to this neuronal loss is poorly understood. Seborrheic dermatitis (SD) is a common benign inflammatory condition of the skin which mainly affects lipid-rich regions of the head and trunk. SD is caused by over proliferation of the lipophilic fungus Malassezia. PD and SD are strongly associated. The increased PD risk following an SD diagnosis (OR = 1.69, 95% CI 1.36, 2.1; p < 0.001) reported by Tanner and colleagues remains unexplained. Malassezia were historically considered commensals confined to the skin. However, many recent studies report finding Malassezia in internal organs, including the CNS. This raises the possibility that Malassezia might be directly contributing to PD. Several lines of evidence support this hypothesis. AIDS is causally associated with both parkinsonism and SD, suggesting that weak T cell-mediated control of commensal microbes such as Malassezia might contribute to both. Genetic polymorphisms associated with PD (LRRK2, GBA, PINK1, SPG11, SNCA) increase availability of lipids within human cells, providing a suitable environment for Malassezia. Four LRRK2 polymorphisms which increase PD risk also increase Crohn's disease risk; Crohn's disease is strongly associated with an immune response against fungi, particularly Malassezia. Finally, Malassezia hypha formation and melanin synthesis are stimulated by L-DOPA, which could promote Malassezia invasiveness of dopamine neurons, and contribute to the accumulation of melanin in these neurons. Although Malassezia's presence in the substantia nigra remains to be confirmed, if Malassezia play a role in PD etiology, antifungal drugs should be tested as a possible therapeutic intervention.

Parkinson's disease pathogenesis, evolution and alternative pathways: A review

Sporadic Parkinson's disease (PD) is one of the most common neurodegenerative diseases of the elderly. In the scientific literature, surveys aiming to investigate the potential diagnostic biomarkers for PD have focused on skin and intestinal tissue biopsies, whereas more recent studies have reported an association between PD and skin disorders, such as seborrheic dermatitis and rosacea. In addition, a connection between PD and Crohn's disease has been established. These data suggest the hypothesis of a possible link between the gastrointestinal tract and skin and the development of PD. In fact, the nervous system, gastrointestinal tract and skin are analogous in their embryological development and, therefore, have molecular networks and pathogenic pathways in common. Based on these data, it may be assumed that the gastrointestinal tract and skin might be implicated in the pathogenesis of PD. The evolutionary hypothesis might also be a useful tool for further investigations into the overlap across neurological, gastrointestinal and skin disorders.

Prevalence and determinants of seborrhoeic dermatitis in a middle-aged and elderly population: the Rotterdam Study

BACKGROUND

Seborrhoeic dermatitis is a chronic relapsing inflammatory skin disease with unclear pathophysiological mechanisms.

OBJECTIVES

To establish which lifestyle and physiological determinants are associated with seborrhoeic dermatitis.

METHODS

Seborrhoeic dermatitis was diagnosed by a trained physician during a full-body skin examination within the Rotterdam Study, a prospective population-based cohort study in middle-aged and elderly people. The current design is a comparative cross-sectional study embedded in the Rotterdam Study. Potential factors were identified from the literature and analysed in a multivariable logistic regression, including: age, sex, obesity, skin colour, stress, depression, education level, hypertension, climate, xerosis cutis, alcohol and tobacco use.

RESULTS

Of the 5498 participants, 788 participants were diagnosed with seborrhoeic dermatitis (14·3%). We found associations between seborrhoeic dermatitis and male sex [adjusted odds ratio (OR) 2·09, 95% confidence interval (CI) 1·77-2·47], darker skin (adjusted OR 0·39, 95% CI 0·22-0·69), season (summer vs. winter: adjusted OR 0·63, 95% CI 0·48-0·82) and generalized xerosis cutis (adjusted OR 1·41, 95% CI 1·11-1·80).

CONCLUSIONS

Seborrhoeic dermatitis is one of the most common inflammatory dermatoses in middle-aged and elderly individuals, especially during winter. Men, and people with a light and dry skin were most likely to have seborrhoeic dermatitis.

The Skin and Parkinson's Disease: Review of Clinical, Diagnostic, and Therapeutic Issues

BACKGROUND

Parkinson's disease (PD) and the skin are related in a number of ways, including clinical abnormalities of the disease itself and skin-related side effects of dopaminergic medication, pumps, and surgical therapies. Recent advances in understanding the role of α-synuclein suggest skin biopsies as a potential diagnostic or even a premotor marker of PD.

METHODS

The PubMed database was searched for publications up to October 2015, and the current evidence on skin-related issues in PD was comprehensively summarized.

RESULTS

The evidence was summarized on the prevalence, etiology, and management of seborrheic dermatitis, sweating dysfunctions, bullous pemphigoid, and malignant melanoma, as well as therapy-related skin disorders, especially those observed in amantadine, rotigotine, apomorphine, and levodopa/carbidopa intestinal gel therapies and deep-brain stimulation. Skin biopsies evaluating the presence of α-synuclein, the density and morphology of cutaneous nerves, and skin fibroblast functions also are discussed.

CONCLUSIONS

Skin disorders are a common manifestation of PD. However, the exact pathophysiology and prevalence of these disorders are not well understood, and more systematic research is needed in this regard. Peripheral tissue biopsies as a diagnostic marker of PD are an exciting avenue in future PD research, although multiple caveats and pending issues need to be solved before they can be used in routine clinical practice.

Analysis of Dermatologic Diseases in Neurosurgical In-Patients: A Retrospective Study of 463 Cases

BACKGROUND

Both the skin and the neurologic system are derived from the ectoderm during embryogenesis, and thus patients with neurologic disorders may have accompanying dermatologic diseases. For example, seborrheic dermatitis is more frequently observed in patients with Parkinsonism and other neurologic disorders. To date, however, there has been limited review on dermatologic diseases in neurosurgical in-patients.

OBJECTIVE

The purpose of this study was to characterize dermatological problems encountered in a neurosurgery unit and to compare these data to previous reports of in-patient dermatologic consultations.

METHODS

A retrospective review was conducted over all in-patient dermatology consultations from the neurosurgery unit during a 3-year period.

RESULTS

Of 2,770 dermatology consultations, 463 (16.7%) came from the department of neurosurgery. The most frequent age group was the 6th decade of life, and the ratio of men to women was 1.07. Consults were most frequently placed from patients with intracranial hemorrhage (23.8%). Eczema/dermatitis (36.5%; n=204) and cutaneous infections (27.0%; n=151) accounted for more than half of all dermatological consultations, followed by cutaneous adverse drug reactions (11.8%; n=66). Additionally, seborrheic dermatitis was significantly more frequent (p=0.048, odds ratio=1.96) in patients with intracranial hemorrhage.

CONCLUSION

This study characterizes the distribution of skin disorders in patients admitted to the neurosurgery service based on the consultations that have been made for dermatologic evaluation. Collaboration between the neurosurgeons and dermatologists may improve the quality of patient care and help to better predict the occurrence of these conditions.

Seborrheic Dermatitis and Dandruff: A Comprehensive Review

Seborrheic Dermatitis (SD) and dandruff are of a continuous spectrum of the same disease that affects the seborrheic areas of the body. Dandruff is restricted to the scalp, and involves itchy, flaking skin without visible inflammation. SD can affect the scalp as well as other seborrheic areas, and involves itchy and flaking or scaling skin, inflammation and pruritus. Various intrinsic and environmental factors, such as sebaceous secretions, skin surface fungal colonization, individual susceptibility, and interactions between these factors, all contribute to the pathogenesis of SD and dandruff. In this review, we summarize the current knowledge on SD and dandruff, including epidemiology, burden of disease, clinical presentations and diagnosis, treatment, genetic studies in humans and animal models, and predisposing factors. Genetic and biochemical studies and investigations in animal models provide further insight on the pathophysiology and strategies for better treatment.

Seborrheic pemphigoid

Seborrheic pemphigoid (SP), first described in 1969 by Schnyder, is a peculiar variant of BP which clinically resembles pemphigus erythematosus, since it is characterized by ruptured bullae and erosions covered with crusts involving the seborrheic areas. To the best of our knowledge, from the first description only four other cases of SP have been reported, of which two are in the English literature. We report an additional case of SP in a 56-year-old man with cervical spondylogenic myelopathy with very impaired mobility.

A laboratory-based study on patients with Parkinson's disease and seborrheic dermatitis: the presence and density of Malassezia yeasts, their different species and enzymes production

BACKGROUND

Seborrheic dermatitis (SD) and Parkinson's disease (PD) are frequently associated conditions. Aims of this study were: to determine severity of SD, presence of different species and density of Malassezia yeasts; to assess yeast lipases and phosphatases production in vitro and to compare these results between SD patients with and without PD.

METHODS

This case-control prospective study was conducted at the Dermatology and Neurology Units, Clinical Centre of Serbia and at the National Medical Mycology Reference Laboratory, University of Belgrade Medical School, Serbia. A total of 90 patients and 70 healthy controls (HC) were investigated: 60 patients with SD (SDN) and 30 patients with SD and PD (SDP). Culture-based mycological examination was carried out on lesional skin (LS) and non-lesional skin (NLS). A yeasts density was determined by counting the Malassezia colony forming units per tape (CFU/tape). Enzymes production by isolated Malassezia was investigated.

RESULTS

The most patients with SD were male (76.7%; SDP and 63.3%; SDN) and the intensity of SD was dominantly severe or moderate (76.7%; SDP and 75%; SDN). The presence of Malasseziа was high on LS in both groups (87.3%; SDP and 86.7%; SDN) (p=0.667).The highest yeasts density (mean CFU/tape=67.8) was detected on LS in 53% of SDP group and in 21.7% of SDN group (mean CFU/tape=31.9) (p < 0.01). The presence of negative cultures was lower in SDP group (13.3%) in comparison to HC and SDN groups (37% and 31.7%, respectively). Malassezia density on NLS in SDP group (mean CFU/tape=44.3) was significantly higher in comparison to SDN and HC (p=0.018). M. globosa was the most abundant species identified amongst isolates from the SDP group (42.3%) and exhibited high production of phosphatase and lipase in vitro.

CONCLUSION

From this laboratory-based study a positive correlation between SD, PD, M. globosa incidence, high yeast density and high phosphatase and lipase activity was established. Our data lead to conclusion that local skin performance of PD patient's characterized with increased sebum excretion ratio play a role in SD by stimulation of yeasts replication and enzyme production.

Bioelectrocatalytic sensor for triglycerides in human skin sebum based on enzymatic cascade reaction of lipase, glycerol kinase and glycerophosphate oxidase

We report the development of an electrochemical biosensor for the quantification of triglycerides in human skin sebum, based on a multienzyme cascade reaction. The presence of excessive triglycerides in human sebum is one of the leading causes of various skin ailments. However, to the best of our knowledge, no bioelectrocatalytic approach for the quantification of sebum triglycerides has been made. In order to develop triglyceride biosensor, we fabricated a multienzyme-associated electrode incorporating lipase, glycerol kinase, and glycerophosphate oxidase. Enzymes were deposited by electrostatic force and further stabilized via crosslinking between enzymes and polymer matrices. The enzyme-modified biosensing electrode maintained its bioelectrocatalytic activity for five days. An additional constraint was the limited solubility of sebum triglycerides in aqueous electrolytes, impeding the analysis. To address this issue, triglyceride samples were prepared in the form of micelles, enabling efficient sample preparation for biosensor signaling. Calibration tests revealed that the designed assay had a detection range of 15-200mg/dL of micellar triglyceride, which covered the required determination range. The developed biosensing approach was successfully used to determine triglyceride concentrations in real sebum samples of unknown triglyceride content.

Dermatite seborreica

A dermatite seborreica é uma doença eritêmato-escamativa de caráter crônico-recidivante que acomete entre 1 e 3% da população geral dos Estados Unidos. Possui dois picos de incidência - o primeiro, durante os três primeiros meses de vida, e o segundo, a partir da puberdade, atingindo seu ápice entre os 40 e 60 anos de idade. Os indivíduos HIV positivos têm maior prevalência da doença, que apresenta maior intensidade e tendência à refratariedade ao tratamento. Doenças neurológicas e outras doenças crônicas também estão associadas ao desenvolvimento da dermatite seborreica. Como mecanismo fisiopatogênico, reconhece-se que o fungo Malassezia sp., presente na pele de indivíduos suscetíveis, leve a uma irritação não-imunogênica a partir da produção de metabólitos à base de ácidos graxos insaturados deixados na superfície cutânea. Este artigo faz uma revisão da literatura sobre dermatite seborreica, com ênfase nos aspectos imunogenéticos, formas clínicas e tratamento.

Impression cytology and ocular surface characteristics in patients with seborrhoeic dermatitis

PURPOSE

To evaluate the clinical findings, tear film functions and ocular surface changes in patients with seborrhoeic dermatitis.

METHODS

This prospective study involved 63 patients with seborrhoeic dermatitis (Group 1) and 65 control subjects (Group 2). Best-corrected visual acuity measurement, slit-lamp examination, Schirmer I test, tear film break-up time (BUT), Rose Bengal staining and conjunctival impression cytology were performed in all patients. Subjective ocular complaints were scored using an Ocular Surface Disease Index (OSDI) questionnaire. Results between the two groups were compared.

RESULTS

In group 1, meibomitis, blepharitis and conjunctival hyperemia were seen significantly more frequently than in group 2 (p < 0.001). Impression cytology revealed grade 0 changes in 25 (39.6%) eyes, grade 1 changes in 22 (34.9%) eyes, grade 2 changes in 13 (20.6%) eyes and grade 3 changes in 3 (4.7%) eyes in group 1, whereas grade 0 changes in 48 (73.8%) eyes, grade 1 changes in 11 (16.9%) eyes and grade 2 changes in 6 (9.2%) eyes were seen in group 2 (p = 0.032). Mean goblet cell density was 795 ± 55 cells/mm(2) in group 1 and 1820 ± 100 cells/mm(2) in group 2 (p < 0.001). Mean Schirmer I and mean BUT results were statistically lower in group 1 than in group 2 (p = 0.043 and p < 0.001, respectively). Mean Rose Bengal scores and mean OSDI scores were statistically higher in group 1 than in group 2 (p = 0.002 and p < 0.001, respectively).

CONCLUSIONS

Our data show that patient with seborrhoeic dermatitis has decreased tear production, tear film instability and significant degeneration of the ocular surface epithelium, compared with normal subjects.

Clinical implications of aging skin: cutaneous disorders in the elderly

Aging skin undergoes progressive degenerative change. Structural and physiologic changes that occur as a natural consequence of intrinsic aging combined with the effects of a lifetime of ongoing cumulative extrinsic damage and environment insult (e.g. overexposure to solar radiation) can produce a marked susceptibility to dermatologic disorders in the elderly. As skin ages, the vasculature progressively atrophies. The supporting dermis also deteriorates, with collagen and elastin fibers becoming sparse and increasingly disordered. These changes leave the elderly increasingly susceptible to both vascular disorders such as stasis dermatitis and skin injuries such as pressure ulcers and skin tears, with a steadily decreasing ability to effect skin repair. A parallel erosion of normal immune function produces higher levels of autoimmune skin disorders such as bullous pemphigoid, benign mucous membrane pemphigoid, paraneoplastic pemphigoid, and pemphigus vulgaris. Lichen sclerosus, an autoimmune disorder often occurring in the genital area in older women, is not common but is an important development because of the potential for substantial discomfort as well as serious complications. The prevalence of polypharmacy in this population increases the risk for autoimmune drug reactions, and diagnosis should be undertaken with an awareness that polypharmacy in this population creates a greatly increased susceptibility to drug eruptions that can mimic other cutaneous disorders. Immunologic senescence in the elderly also sets the stage for potential reactivation of the Varicella zoster virus, in which initial dermatologic involvement expands into the major sensory ganglia. Known as shingles, this disorder can be excruciatingly painful with the potential to cause blindness if the optic nerve becomes involved. Dermatoses such as xerosis, pruritus, and eczema are also widespread in the elderly, create substantial suffering in those afflicted, and often prove recalcitrant to treatment. Individual susceptibility to specific types of contact dermatitis changes over the lifetime, and seborrheic dermatitis is substantially more prevalent in the elderly. It is not uncommon for older patients to have multiple impairments, with the potential for cognitive dysfunction as well as impaired vision, hearing, or mobility. In addition, they may not have adequate housing or nutrition, or the financial resources necessary for adequate compliance. Physicians must take into consideration the patient's physical ability to comply with the recommended therapy as well as socioeconomic factors that may impact on compliance. Simple topical regimens are preferable wherever possible in order to maximize compliance and, therefore, efficacy. Extra effort may be necessary to ensure that instructions are accurately followed and that ongoing compliance with the regimen prescribed is actually achieved. Management of dermatologic disorders in the elderly is often less than optimal, due to the fact that the special needs and limitations of this population are not adequately considered. Treatments should consider the intrinsic differences between younger and older patients that may impact on diagnosis and therapy choice. The aged patient is often afflicted with numerous co-morbidities that can influence the choice of therapy. Skin integrity in the elderly is compromised, and safety concerns are increased with the long-term use of any medication prescribed. In addition, the prevalence of polypharmacy in the aged population substantially increases the risk of cutaneous drug reactions, which can profoundly complicate accurate diagnosis of dermatologic disorders. The aged population also needs to be more closely monitored because of increased fragility of the skin and the physical limitations that may hinder compliance with prescribed regimens.