Assuntos
Pelagra , Zea mays , Humanos , Etiópia , Pelagra/epidemiologia , Masculino , Feminino , Adulto , Pessoa de Meia-IdadeRESUMO
BACKGROUND: Pellagra caused by niacin deficiency in alcoholics can be easily misdiagnosed because of similar symptoms to other alcohol-related diseases and the lack of the classical triad of signs. AIM: This study aimed to define the clinical presentation of alcoholic pellagra for early diagnosis and timely treatment. METHODS: The clinical data of 16 alcohol-dependent patients who had pellagra and treated in our hospital from January 2002 to December 2019 were retrospectively analyzed. The local medical ethics committee approval (Medical Ethics Committee of Affiliated Hospital of XuZhou Medical University, XYFY2020-KL247-02) for this study has been obtained. RESULTS: The main complaints of the 16 patients were skin lesions (six cases), diarrhea (six cases), and mental disorders (four cases). Then, 13 cases had typical skin lesions, and 3 patients had a full spectrum of diarrhea, dementia, and dermatitis (3D). In terms of the main diagnosis, 2 patients had pellagra and Wernicke's encephalopathy, 3 patients had pellagra and alcohol-withdrawal syndrome, and the other patients had pellagra. After sufficient amounts of niacin and multivitamin B were given, clinical symptoms improved rapidly, and no sequelae were observed during follow-up. CONCLUSIONS: Pellagra is rarely manifested as a full 3D spectrum, with only one or two characteristics, which lack diagnostic specificity, especially in individuals with alcoholism. Physicians should maintain a high degree of suspicion of niacin deficiency in alcoholics. Alcohol-dependent patients with pellagra may be accompanied by complications of Wernicke's encephalopathy and alcohol-withdrawal syndrome. Prompt identification and timely treatment with a sufficient amount of niacin in combination with other vitamins and a certain amount of Zn can achieve a good prognosis of pellagra.
Assuntos
Alcoolismo , Niacina , Pelagra , Dermatopatias , Encefalopatia de Wernicke , Humanos , Pelagra/diagnóstico , Pelagra/epidemiologia , Pelagra/etiologia , Estudos Retrospectivos , Niacina/uso terapêutico , Encefalopatia de Wernicke/complicações , Encefalopatia de Wernicke/diagnóstico , Encefalopatia de Wernicke/tratamento farmacológico , Alcoolismo/complicações , Alcoolismo/diagnóstico , Alcoolismo/tratamento farmacológico , Vitaminas , Diarreia/complicações , Diarreia/tratamento farmacológico , Dermatopatias/tratamento farmacológico , Etanol/uso terapêuticoRESUMO
Pellagra is characterized by "dermatitis - diarrhea - dementia - death". Various causes were discussed over the course of two centuries. The initial presumption was that the sun caused changes in exposed areas of the body. The "Zeïsts" blamed the maize (corn), which forms the main constituent in the diet of poor peoples, for being an insufficient nutrient and thus causing the pellagra in such indigent populations. The "Toxikozeïsts", however, regarded toxins produced by innocuous bacteria and fungi in unripe or in ripe but badly stored maize or in maize flour or in poorly baked maize bread as the cause of pellagra. Pellagra as an allergic disease was also discussed. Self-experiments of Goldberger's group in 1916 and finally Elvehjem's detection of niacin deficiency in maize in 1937 solved the problem.In the Austrian empire and (from 1867 on) in the Austro-Hungarian monarchy, pellagra was diagnosed and combated in the provinces of Küstenland, Tirolia and Bukovina and in Hungary. Originally believing in the noxiousness of maize in the poor population, extensive measures were planned and partially executed. Primarily measures for providing salubrious maize products were planned for the population, such as public bakeries and eating houses, kilns and storage houses for maize. For the treatment of pellagra patients, so-called pellagrosaria and auxiliary hospitals were established and the number of general practitioners was increased. It was also important to educate the population about preventing pellagra by consuming proper food. Pellagra funds to sustain the measures were established. In the provinces, pellagra commissions, chaired by the governor and consisting of twelve experts of the relevant medical branches, were appointed as an advisory and expert body.
Assuntos
Pelagra , Áustria , Diarreia , Humanos , Hungria , Pelagra/epidemiologia , PobrezaRESUMO
In mid-June 2019, 3 months after cyclone Idai landfall in Mozambique, health authorities of Nhamatanda district reported an outbreak of Pellagra. Applying a mixed-method protocol, we carried out an investigation to characterize cases of pellagra, identify the associated factors for the outbreak using a case-control study, and explore the perceived impact on food security (availability, access, and usage) before and after Idai. We collected data from 121 cases and 121 controls and conducted in-depth interviews with 69 heads of households. The cases were more likely to be female (P < 0.01) and less educated (P < 0.01) than controls. Insufficient consumption of chicken and peanut before cyclone Idai arrival were statistically associated with pellagra (P < 0.05). From interviewed households' heads, 51% were experiencing food shortages even before the cyclone hit. Cyclone Idai served as a trigger to reduce niacin consumption below the threshold that protected Nhamatanda population from pellagra and caused a ≈2,300 case (707.9/100,000 inhabitants) outbreak.
Assuntos
Tempestades Ciclônicas , Surtos de Doenças , Pelagra/epidemiologia , Pelagra/etiologia , Adolescente , Estudos de Casos e Controles , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Moçambique/epidemiologia , Razão de Chances , Pele/patologiaRESUMO
OBJECTIVE: Pellagra is a nutritional deficiency disease associated with niacin (vitamin B3) deficiency. The history of pellagra is well documented for Europe and the USA, but less is known about the prevalence in sub-Saharan African countries. This study documents the history of pellagra in South Africa, as diagnosed based on dermatological symptoms. DESIGN: Scoping review of information from scientific databases, library archives, other archives and record services and from Statistics South Africa. SETTING: South Africa, 1897-2019. PARTICIPANTS: South African. RESULTS: Pellagra was first officially recorded in South Africa in 1906, but there are earlier indications of the disease. The prevalence of pellagra peaked after it was all but eradicated in the USA and Europe. Pellagra was never as prevalent in South Africa as in Europe, the USA and Egypt, where special hospitals for pellagrins were established. However, studies on urinary excretion of metabolites conducted in 1960s and 1970s suggested a high prevalence of subclinical (sub-pellagra) niacin deficiency, especially in previously disadvantaged Black populations. As in Europe and the USA, pellagra was associated with poverty and an overdependence on maize as staple food. Malnutrition was the main cause of the disease, but alcohol abuse might have been a contributing factor. In South Africa, reports of pellagra had declined by the late 1980s/early 1990s and hardly any cases were reported by the year 2000. CONCLUSIONS: Although pellagra, diagnosed based on dermatological symptoms, appears to be largely eradicated in South Africa, it does not rule out the potential for subclinical niacin deficiency.
Assuntos
Niacina , Pelagra , Europa (Continente) , Humanos , Pelagra/epidemiologia , Pobreza , África do Sul/epidemiologiaRESUMO
Pellagra, caused by vitamin B3 (niacin) deficiency, is traditionally described as dermatitis, diarrhea, dementia (3D), and even death (4D) syndrome if not recognized and treated promptly. Although full-blown pellagra with all 3D features has become rare, pellagra still exists, especially in high-risk populations, which is actually more prevalent than we think. We report that a recently treated patient with the full spectrum of 3D clinical features of pellagra presents as chronic diarrhea of unknown etiology for 1 year. It reminds us that keeping a high index of suspicion and maintaining a broad differential diagnosis are critical for recognition and management of this potentially fatal but treatable condition.
Assuntos
Diarreia/diagnóstico , Pelagra/diagnóstico , Idoso de 80 Anos ou mais , Alcoolismo/epidemiologia , Demência/etiologia , Dermatite/etiologia , Diagnóstico Diferencial , Diarreia/etiologia , Humanos , Masculino , Niacina/sangue , Niacina/uso terapêutico , Niacinamida/sangue , Pelagra/complicações , Pelagra/tratamento farmacológico , Pelagra/epidemiologia , Prevalência , Fatores de Risco , Pele/patologia , Resultado do Tratamento , Complexo Vitamínico B/uso terapêuticoRESUMO
OBJECTIVE: The aim of this study was to describe the epidemiological, clinical, and therapeutic profile as well as the outcome and to document the causes of pellagra and pellagra-like erythema in a hospital setting in Lomé, Togo. METHODS: This retrospective study examined the records of patients seen for outpatient consultation and/or hospitalization in the three public dermatology departments of Lomé from January 1997 to September 2017. RESULTS: During the study period, 178 (0.4%) of 47,219 patients seen in these dermatology departments consulted for pellagra or pellagra-like erythema; 159 (89.3%) had pellagra-like erythema. The patients' mean age was 45.8±16 years, and the sex ratio (M/F) 1.8. All patients had at least one site of cutaneous involvement, nearly always erythematous or pigmented lesions in the photo-exposed areas (99.4% of cases). Gastrointestinal and neurological signs were dominated respectively by diarrhea (12.4 % of cases), peripheral neuropathies (8.4% of cases) and insomnia (8.4% of cases). The main causes identified were alcoholism (42.1% of cases) and nutritional deficiency (6.7% of cases). Five of 178 patients were infected with HIV. All patients were treated with nicotinamide and multivitamin supplementation. No deaths were recorded during follow-up. CONCLUSION: Our results document the extreme rarity of pellagra-like erythema/pellagra. Its two main causes remain alcoholism and nutritional deficiency. Moreover, its prognosis is good when treated quickly and adequately.
Assuntos
Alcoolismo/complicações , Eritema/epidemiologia , Desnutrição/complicações , Pelagra/epidemiologia , Alcoolismo/epidemiologia , Diarreia/epidemiologia , Diarreia/etiologia , Eritema/etiologia , Feminino , Humanos , Masculino , Desnutrição/epidemiologia , Pessoa de Meia-Idade , Niacinamida/uso terapêutico , Pelagra/terapia , Doenças do Sistema Nervoso Periférico/epidemiologia , Doenças do Sistema Nervoso Periférico/etiologia , Estudos Retrospectivos , Distúrbios do Início e da Manutenção do Sono/epidemiologia , Distúrbios do Início e da Manutenção do Sono/etiologia , Togo/epidemiologia , Complexo Vitamínico B/uso terapêuticoRESUMO
AIM: To define the prevalence and clinical presentation of pellagra, a multi-systemic disease caused by the deficiency of niacin, in patients admitted to a tertiary addiction treatment centre in southern India, with alcohol dependence syndrome (ADS)-(ICD10). METHODS: Review of the health records of 2947 patients who received inpatient care for ADS between 2015 and 2017. RESULTS: Out of 2947, 31 (1%) were diagnosed with pellagra. Nearly two-thirds (64.5%) of those with pellagra were from a low-income group. Of the clinical-triad of pellagra, all patients had dermatitis, more than half (58%) had delirium, a minority (19%) had diarrhoea. Nearly two-thirds (61%) had presented in a complicated-withdrawal state. Associated conditions included peripheral neuropathy (32%); Wernicke's encephalopathy (26%); seizures (16%).Seventeen (54%) had BMI <18.5 kg/m2. Treatment was a high dose of parenteral vitamins including niacin (mean dose: 1500 mg/day) for an average of 7.5 days followed by oral multivitamin supplements. All had complete resolution of pellagrous symptoms by the end of the three weeks of inpatient care. CONCLUSIONS: Pellagra is an acute medical condition, frequently encountered in the context of alcohol dependence and poverty. It often presents with other disabling and life-threatening comorbidities like delirium tremens and Wernicke's encephalopathy. The classical triad of pellagra is only seen in a minority of cases. Thus a high index of suspicion is required lest pellagra may remain undiagnosed. Prompt identification and treatment with a high dose of niacin in combination with other vitamins result in complete recovery.
Assuntos
Delirium por Abstinência Alcoólica/epidemiologia , Alcoolismo/epidemiologia , Síndrome de Korsakoff/epidemiologia , Pelagra/epidemiologia , Adulto , Alcoolismo/complicações , Comorbidade , Humanos , Índia/epidemiologia , Síndrome de Korsakoff/complicações , Niacina/uso terapêutico , Pelagra/complicações , Pelagra/diagnóstico , Pelagra/tratamento farmacológico , Pobreza/estatística & dados numéricos , Prevalência , Centros de Tratamento de Abuso de Substâncias/estatística & dados numéricos , Atenção Terciária à Saúde/estatística & dados numéricos , Vitaminas/uso terapêutico , Adulto JovemRESUMO
AbstractPellagra is a deficiency of niacin or its amino acid precursor, tryptophan, which presents with the classic four Ds: the characteristic dermatitis, diarrhea, dementia, and eventually death if left untreated. The incidence of pellagra is quite rare presently because of increased awareness and strategies such as vitamin fortification. However, the deficiency is still present in cultures that rely on maize as their primary source of sustenance. We report a recent outbreak in a catchment area in Kasese, Malawi, of 691 cases of pellagra which were successfully treated with niacin supplementation. We present this short report to highlight the importance of educating providers of at-risk populations about this diagnosis and to consider solutions for these populations to prevent further deficiencies.
Assuntos
Suplementos Nutricionais , Surtos de Doenças , Niacina/administração & dosagem , Pelagra/dietoterapia , Pelagra/epidemiologia , Adolescente , Adulto , Demência/diagnóstico , Dermatite/diagnóstico , Diarreia/diagnóstico , Feminino , Humanos , Incidência , Malaui/epidemiologia , Masculino , Pessoa de Meia-Idade , Niacina/deficiência , Educação de Pacientes como Assunto , Pelagra/diagnóstico , Pelagra/metabolismoRESUMO
BACKGROUND: As global population of the elderly continues to rise, a critical need to provide it with health services, including dermatology, will be significant, especially in developing countries like Tanzania. To adequately meet their dermatologic needs, knowledge of local patterns of skin conditions is vital. This study was aimed to describe the spectrum of skin diseases among elderly patients attending skin clinic at the Regional Dermatology Training Centre (RDTC) in Northern Tanzania. METHODS: A descriptive hospital based cross-sectional study was conducted between January 2013 and April 2013 at RDTC and included all patients aged 55 years and above who consented to be examined. Diagnoses were clinical, diagnostic tests being done only when necessary. Ethical clearance to conduct the study was granted. RESULTS: A total of 142 patients, age ranges 55-99 years, median age of 67.5 years were seen. Eczemas were the leading disease group (43.7%), with unclassified eczemas (33.9%) predominating. Papulosquamous disorders (15.4%) were second with psoriasis (50%) being the leading disease. Infections (11.3% with fungal infections the leading group representing 5.6% of all diseases), tumours (9.8%: Kaposi's sarcoma 4.2%), vascular disorders 9.1% (lymphedema 4.9%), autoimmune disorders 7.7% (connective tissue diseases 4.9%), vitiligo 4.2%, nutritional diseases 2.1% (pellagra 0.7%), urticaria 0.7% and drug reactions 0.7%. CONCLUSIONS: Eczemas are the most common group of disorders among elderly patients presenting at RDTC.
Assuntos
Eczema/epidemiologia , Micoses/epidemiologia , Sarcoma de Kaposi/epidemiologia , Dermatopatias Papuloescamosas/epidemiologia , Idoso , Idoso de 80 Anos ou mais , Instituições de Assistência Ambulatorial , Doenças Autoimunes/diagnóstico , Doenças Autoimunes/epidemiologia , Doenças Autoimunes/patologia , Estudos Transversais , Toxidermias/diagnóstico , Toxidermias/epidemiologia , Toxidermias/patologia , Eczema/diagnóstico , Eczema/patologia , Feminino , Humanos , Linfedema/diagnóstico , Linfedema/epidemiologia , Linfedema/patologia , Masculino , Pessoa de Meia-Idade , Micoses/diagnóstico , Micoses/patologia , Pelagra/diagnóstico , Pelagra/epidemiologia , Pelagra/patologia , Sarcoma de Kaposi/diagnóstico , Sarcoma de Kaposi/patologia , Pele/patologia , Dermatopatias Papuloescamosas/diagnóstico , Dermatopatias Papuloescamosas/patologia , Tanzânia/epidemiologia , Urticária/diagnóstico , Urticária/epidemiologia , Urticária/patologia , Vitiligo/diagnóstico , Vitiligo/epidemiologia , Vitiligo/patologiaRESUMO
This article explores the extent to which the bacterial concept of disease acted as an obstacle to the understanding of deficiency diseases, by focusing on explorations into the cause of pellagra in the early twentieth century. In 1900, pellagra had been epidemic in Italy for 150 years and was soon to become so in the United States, yet the responses of medical investigators differed substantially. To account for these, the article reconstructs the sharply contrasting reactions to a provocative theory proposed by Louis Sambon. Applying a tropical diseases approach to pellagra, Sambon argued that pellagra had nothing at all to do with maize consumption, as the Italians had long thought, but was caused by the bite of a parasite-carrying insect. Italian pellagrologists, involved in a dogmatic quest for a toxin in maize, and with pellagra rates there on the decline, marginalized the Sambon hypothesis. By contrast, in the United States, with pellagra on the rise, the dominant infectious paradigm put Sambon center stage, his proposed etiology shaping the earliest American investigations. When the deficiency disease concept gained currency in 1913, the relatively closed world of Italian pellagrology was wrong-footed, while the more open-ended U.S. community was better able to follow up the new lead. The article discusses what these shifts and the resulting controversies reveal about the medical contexts. The actor-centered approach, with reaction to Sambon's intervention as a kind of test-case, is the key to understanding these controversies and why they mattered.
Assuntos
Epidemias/história , Pelagra/etiologia , Pelagra/história , História do Século XX , Humanos , Itália/epidemiologia , Pelagra/epidemiologia , Estados Unidos/epidemiologiaRESUMO
As pellagra reached epidemic proportions in the United States in the early 20th century, 2 teams of investigators assessed its incidence in cotton mill villages in South Carolina. The first, the Thompson-McFadden Commission, concluded that pellagra was likely infectious. The second, a Public Health Service investigation led by Joseph Goldberger, concluded that pellagra was caused by a dietary deficiency. In this paper, we recount the history of the 2 investigations and consider how the differences between the 2 studies' designs, measurements, analyses, and interpretations led to different conclusions. Because the novel dietary assessment strategy was a key feature of the Public Health Service's study design, we incorporated simulated measurement error in a reanalysis of the Public Health Service's data to assess whether this specific difference affected the divergent conclusions.
Assuntos
Pelagra/história , Indústria Têxtil/história , Pesquisa Biomédica/história , Feminino , História do Século XX , Humanos , Incidência , Masculino , Fenômenos Fisiológicos da Nutrição , Pelagra/epidemiologia , Saúde Pública/história , Projetos de Pesquisa , South Carolina/epidemiologiaRESUMO
BACKGROUND: Alcohol withdrawal delirium (AWD) is associated with significant morbidity and mortality. Pellagra (niacin deficiency) can be a cause of delirium during alcohol withdrawal that may often be overlooked. OBJECTIVES: We present a three-patient case series of pellagrous encephalopathy (delirium due to pellagra) presenting as AWD. METHODS: We provide a brief review of pellagra's history, data on pellagra's epidemiology, and discuss pellagra's various manifestations, particularly as related to alcohol withdrawal. We conclude by providing a review of existing guidelines on the management of alcohol withdrawal, highlighting that they do not include pellagrous encephalopathy in the differential diagnosis for AWD. RESULTS: Though pellagra has been historically described as the triad of dementia, dermatitis, and diarrhea, it seldom presents with all three findings. The neurocognitive disturbance associated with pellagra is better characterized by delirium rather than dementia, and pellagra may present as an isolated delirium without any other aspects of the triad. DISCUSSION: Although endemic pellagra is virtually eradicated in Western countries, it continues to present as pellagrous encephalopathy in patients with risk factors for malnutrition such as chronic alcohol intake, homelessness, or AIDS. It may often be mistaken for AWD. Whenever pellagra is suspected, treatment with oral nicotinamide (100 mg three times daily for 3-4 weeks) prior to laboratory confirmation is recommended as an inexpensive, safe, and potentially life-saving intervention.
Assuntos
Delirium por Abstinência Alcoólica/epidemiologia , Encefalopatias/complicações , Encefalopatias/diagnóstico , Pelagra/diagnóstico , Pelagra/epidemiologia , Delirium por Abstinência Alcoólica/diagnóstico , Alcoolismo/epidemiologia , Diagnóstico Diferencial , Suplementos Nutricionais , Feminino , Pessoas Mal Alojadas , Humanos , Masculino , Pessoa de Meia-Idade , Pelagra/tratamento farmacológico , Guias de Prática Clínica como Assunto , Fatores de RiscoRESUMO
Pellagra was first described in the 18th century as an epidemic in the poverty-stricken Spanish countryside by Gaspar Casal. Pellagra did not appear in the United States until the turn of the 20th century. It then ravaged the Southern United States and was not eliminated until the 1940s. This short report will redact the descriptions of pellagra in two early textbooks of dermatology. The first, published in 1897 before cases of pellagra were recognized in the United States, and, the second, published in 1915 in the midst of the epidemic. The text published in 1915 described in detail the medical signs and symptoms of pellagra particularly as they relate to the skin, as well as speculations as to its cause. The complicated story of the socioeconomic situation of the Southern United States and the hunt for the cause of pellagra will also be discussed briefly.
Assuntos
Dermatologia/história , Pelagra/história , História do Século XX , Humanos , Pelagra/epidemiologia , Pelagra/patologia , Fatores Socioeconômicos , Estados Unidos/epidemiologiaRESUMO
BACKGROUND AND OBJECTIVES: In the developed world, pellagra is a rare condition that is restricted to a small number of at-risk groups. It mainly affects alcoholic patients and those with dietary deficiencies, with intestinal malabsorption, or in treatment with certain drugs. The aim of this study was to analyze the clinical, histopathological, and epidemiological characteristics of patients diagnosed with pellagra in our hospital and to compare the results with the findings traditionally described for this disease. PATIENTS AND METHODS: We undertook a retrospective study of patients with clinical or pathological evidence of pellagra who were seen in our hospital between 1998 and 2009. RESULTS: Seven patients met the inclusion criteria. All were men and the most common predisposing factors were alcoholism and dietary deficiency. All exhibited photosensitivity mainly affecting the forearms and the upper surface of the feet, where the lesions were more severe. The most consistent histopathological findings were the presence of dilated blood vessels with extravasation and little or no inflammatory infiltrate. Various changes were observed in the epidermis, including those suggestive of mild pellagra, such as epidermal pallor and some degree of ballooning of the keratinocytes. Other abnormalities such as epidermal necrosis and hyperkeratosis were also observed. In most patients, pellagra was not initially suspected. Additional noncutaneous findings were observed in almost all cases. CONCLUSIONS: Pellagra should be ruled out in patients with lesions on sun-exposed areas. Predisposing factors for pellagra should be assessed along with the social situation of patients and the presence of digestive or neurological abnormalities.
Assuntos
Pelagra , Adulto , Idoso , Alcoolismo/epidemiologia , Biópsia , Comorbidade , Erros de Diagnóstico , Epiderme/patologia , Humanos , Queratinócitos/patologia , Ceratose/etiologia , Masculino , Desnutrição/epidemiologia , Pessoa de Meia-Idade , Pelagra/diagnóstico , Pelagra/epidemiologia , Pelagra/patologia , Estudos Retrospectivos , Fatores de Risco , Isolamento Social , Espanha/epidemiologia , VasodilataçãoRESUMO
BACKGROUND AND OBJECTIVES: In the developed world, pellagra is a rare condition that is restricted to a small number of at-risk groups. It mainly affects alcoholic patients and those with dietary deficiencies, with intestinal malabsorption, or in treatment with certain drugs. The aim of this study was to analyze the clinical, histopathological, and epidemiological characteristics of patients diagnosed with pellagra in our hospital and to compare the results with the findings traditionally described for this disease. PATIENTS AND METHODS: We undertook a retrospective study of patients with clinical or pathological evidence of pellagra who were seen in our hospital between 1998 and 2009. RESULTS: Seven patients met the inclusion criteria. All were men and the most common predisposing factors were alcoholism and dietary deficiency. All exhibited photosensitivity mainly affecting the forearms and the upper surface of the feet, where the lesions were more severe. The most consistent histopathological findings were the presence of dilated blood vessels with extravasation and little or no inflammatory infiltrate. Various changes were observed in the epidermis, including those suggestive of mild pellagra, such as epidermal pallor and some degree of ballooning of the keratinocytes. Other abnormalities such as epidermal necrosis and hyperkeratosis were also observed. In most patients, pellagra was not initially suspected. Additional noncutaneous findings were observed in almost all cases. CONCLUSIONS: Pellagra should be ruled out in patients with lesions on sun-exposed areas. Predisposing factors for pellagra should be assessed along with the social situation of patients and the presence of digestive or neurological abnormalities.
Assuntos
Pelagra/diagnóstico , Pelagra/epidemiologia , Adulto , Idoso , Humanos , Masculino , Pessoa de Meia-Idade , Pelagra/patologia , Estudos RetrospectivosRESUMO
BACKGROUND: It is proposed that, historically, when the conditions are right for laboratory sciences to contribute to causal knowledge, they take the place of epidemiology as leaders in a given field. METHODS: Review examples of cholera, pellagra, and Kaposi's sarcoma. RESULTS: In the cases of cholera, pellagra, and Kaposi's sarcoma, epidemiology ceased to be at the forefront of knowledge acquisition when laboratory sciences identified more proximate causes than those that epidemiologic group comparisons could reveal. CONCLUSION: These three examples deal with diseases, which, at the individual level, appear to rely predominantly on a single factor. For diseases whose causes still elude specific identification by the laboratory sciences, epidemiology may be uniquely equipped to play a leading role.
Assuntos
Pesquisa Biomédica , Causalidade , Epidemiologia , Cólera/epidemiologia , Técnicas de Laboratório Clínico , Humanos , Pelagra/epidemiologia , Sarcoma de Kaposi/epidemiologiaRESUMO
Niacin has recently been demonstrated to lower blood pressure in hypertensive patients and to reduce cardiovascular events when combined with a statin. As a consequence, niacin has been elevated from being of historical interest as the treatment for pellagra, to being a compound with possible relevance to contemporary therapeutics. In spite of this, niacin deficiency leading to pellagra continues to be a health problem in some countries. Characterized by an exposed-site hyperpigmented dermatitis, pellagra is generally accepted to have been the first photosensitivity syndrome described. At its worst, pellagra manifests as one of the most striking examples of systemic photosensitivity. This is the only photosensitivity syndrome where death is included as a cardinal clinical feature (the often quoted four 'Ds': dermatitis, diarrhoea, dementia and death). However, the pathogenetic mechanism for the photosensitivity caused by niacin deficiency has yet to be determined. This review seeks to update the classification and phenotypic characterization of the various forms of niacin-deficient photosensitivity. Previous speculation about possible mechanisms for the pathogenesis of photosensitivity due to niacin deficiency is reviewed in the context of advances in the understanding of the photochemical basis of photosensitivity reactions. The review concludes by highlighting research required to advance the understanding of this photosensitivity syndrome.