{"title":"Gastrointestinal infections","authors":"S. O'Brien","doi":"10.1093/med/9780198746690.003.0313","DOIUrl":"https://doi.org/10.1093/med/9780198746690.003.0313","url":null,"abstract":"Gastrointestinal infections, especially diarrhoea and vomiting, are responsible for substantial morbidity, mortality, and socioeconomic penalties worldwide. Poor sanitation, inadequate water supplies, and globalization of food production, processing, and retailing increase the risk of large epidemics of food- and waterborne outbreaks of gastrointestinal disease. Acute diarrhoea can be caused by a range of pathogens. Gastrointestinal pathogens usually cause three principal syndromes: acute watery diarrhoea, acute bloody diarrhoea (inflammatory diarrhoea or dysentery), and persistent diarrhoea. They can also cause systemic disease. Patients who do not have high fever (>38.5°C), systemic illness, tenesmus, bloody diarrhoea, a prolonged course (>2 weeks), or dehydration require neither investigation nor treatment. Investigation is required in patients with any of these features, with faecal specimens examined by culture (bacterial pathogens and some protozoa), microscopy (ova, cysts, and parasites), immunoassays (some protozoa and viruses), and molecular methods, usually polymerase chain reaction (PCR) or reverse transcriptase PCR (bacterial toxin genes and viruses). A specific laboratory diagnosis is useful epidemiologically and therapeutically. Oral rehydration therapy is the priority for patients with mild to moderate diarrhoea as long as vomiting is not a major feature. Antimicrobial therapy is not recommended or usually required for uncomplicated diarrhoea, but antibiotic treatment is beneficial for cholera, giardiasis, cyclosporiasis, shigellosis, symptomatic traveller’s diarrhoea, Clostridium difficile diarrhoea, and typhoid. Antimotility drugs are useful in controlling moderate to severe diarrhoea in adults but they are not generally recommended for infants and young children under the age of 4 years. Strict attention to food and water precautions and hand washing helps reduce the risk of gastrointestinal infections. Immunization has not yet proved successful for combating many gastrointestinal pathogens, with the notable exception of rotavirus.","PeriodicalId":347739,"journal":{"name":"Oxford Textbook of Medicine","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115278245","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Benign breast disease","authors":"G. Maclean","doi":"10.1093/med/9780198746690.003.0253","DOIUrl":"https://doi.org/10.1093/med/9780198746690.003.0253","url":null,"abstract":"Benign conditions of the breast are very common, but they cause great anxiety, often leading the patient to be concerned that she has breast cancer. Symptoms may include: a mass in the breast, commonly due to fibroadenoma, benign cystic change, or macrocysts; discharge from the nipple, which may be caused by hyperprolactinaemia, intraduct papilloma, or duct ectasia; and mastalgia. Management involves exclusion of malignancy, often by triple assessment of any palpable abnormality (clinical examination, radiological and pathological assessment), followed by reassurance, with appropriate specific treatment if required. Suspicious features such as a hard, rugged lump in the breast should prompt triple assessment to exclude malignancy. Other benign conditions of the male breast are very rare and male breast cancers account for less than 1% of all breast cancers in the United Kingdom.","PeriodicalId":347739,"journal":{"name":"Oxford Textbook of Medicine","volume":"295 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124275243","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Inflammatory myopathies","authors":"I. Lundberg, H. Chinoy, R. Cooper","doi":"10.1093/med/9780198746690.003.0457","DOIUrl":"https://doi.org/10.1093/med/9780198746690.003.0457","url":null,"abstract":"The idiopathic inflammatory myopathies are a heterogenous group of disorders characterized by muscle weakness, inflammation in muscle tissue, and with frequent extramuscular involvement. Autoantibodies are common, supporting the notion of these disorders being autoimmune. Typically, inflammatory cell infiltrates are found in muscle biopsies. Other organs are frequently involved such as skin, lungs, joints, gastrointestinal tract, and the heart. These heterogenous disorders can be subclassified based on clinical and histopathological features, or by autoantibody specificities. The idiopathic inflammatory myopathies have traditionally comprised polymyositis (PM), dermatomyositis (DM), juvenile DM, PM/DM overlapping with another connective tissue disease, and inclusion body myositis. More recently a subgroup with similar clinical features but with no or scarce inflammation and with pronounced muscle fibre necrosis has been identified and termed immune-mediated necrotizing myopathy.","PeriodicalId":347739,"journal":{"name":"Oxford Textbook of Medicine","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116688464","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Infections of the skin","authors":"R. Hay","doi":"10.1093/med/9780198746690.003.0559","DOIUrl":"https://doi.org/10.1093/med/9780198746690.003.0559","url":null,"abstract":"A huge variety of different organisms exist on healthy skin, the normal microbiome. Under certain circumstances, microbes can actively infect the skin as a primary or secondary event in cutaneous or systemic disease. The most common causes of bacterial infection of the skin are Staphylococcus aureus or β-haemolytic streptococci. There are increasing reports of both hospital- and community-acquired infection by methicillin-resistant S. aureus. Mycobacterium tuberculosis remains a common skin infection in many tropical areas, and syphilis, leprosy, and leishmaniasis are important skin infections in some parts of the world. Dermatophytosis, or ringworm, is caused by mould fungi that can digest keratin (keratinophilic). The diagnosis can be confirmed in the laboratory by examining scrapings or clippings of skin, hair, or nails mounted in potassium hydroxide. Occasionally, in the immunocompromized patient these and other herpes virus infections can disseminate, both to other parts of the skin as well as internally.","PeriodicalId":347739,"journal":{"name":"Oxford Textbook of Medicine","volume":"89 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116941250","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Osteoarthritis","authors":"A. Barr, P. Conaghan","doi":"10.1093/med/9780198746690.003.0450","DOIUrl":"https://doi.org/10.1093/med/9780198746690.003.0450","url":null,"abstract":"Clinical osteoarthritis (OA) is a syndrome of joint pain associated with structural deterioration of synovial joints that over time involves the whole joint organ. It is the most common form of arthritis and a leading cause of chronic pain, disability, and socioeconomic burden. Affected individuals report pain (especially on weight bearing) and joint stiffness leading to loss of muscle strength and poor joint function. This results in reduced participation in valued activities, low mood, sleep disturbance, and poor quality of life. The aetiology of joint deterioration, pain, and the interaction of the two remains unclear. OA is associated with a variety of both modifiable and non-modifiable risk factors including obesity, age, gender, occupational injury, trauma, and genetic predisposition. Obesity is the strongest potentially modifiable risk factor.","PeriodicalId":347739,"journal":{"name":"Oxford Textbook of Medicine","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123239198","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
J. Harrington, R. Agius, D. Warrell, T. Cox, J. Firth
{"title":"Occupational and environmental health","authors":"J. Harrington, R. Agius, D. Warrell, T. Cox, J. Firth","doi":"10.1093/med/9780199204854.003.090401","DOIUrl":"https://doi.org/10.1093/med/9780199204854.003.090401","url":null,"abstract":"Occupational diseases are those for which work or, specifically, exposures in the workplace are necessary causes. The most prevalent occupational diseases in developed countries today are musculoskeletal and psychological disorders (usually stress-related conditions), but generally occupationally related malignancies (e.g. mesothelioma related to asbestos exposure) have the most serious outcomes. The proportion of all cancers attributable to occupational exposures is about 4%, with occupationally related cancers almost exclusively concentrated in manual workers aged 20 or over in sectors such as mining, agriculture, and industry. When presented with a patient whose illness might possibly have been caused or aggravated by work or by other environmental factors, the physician can usefully adopt an approach similar to that used for determining causation in epidemiological studies; the key issues being the temporality, reversibility, exposure-response, strength of association, and specificity of the illness with exposure to the factor in question.","PeriodicalId":347739,"journal":{"name":"Oxford Textbook of Medicine","volume":"127 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123393936","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Bacterial overgrowth of the small intestine","authors":"S. Middleton, R. Playford","doi":"10.1093/med/9780198746690.003.0299","DOIUrl":"https://doi.org/10.1093/med/9780198746690.003.0299","url":null,"abstract":"Small intestinal bacterial overgrowth can be defined as the presence of excessive bacteria in the small intestine which can interfere with digestion and absorption. Predisposing causes include sustained hypochlorhydria induced by proton pump inhibitors, small intestinal dysmotility and stasis due to anatomical or motor abnormalities, and reduced antibacterial activity as seen in immunological deficiency and chronic pancreatitis. Presentation is predominantly from consequences of malabsorption, including gastrointestinal symptoms (e.g. diarrhoea or steatorrhoea) and features of specific nutrient malabsorption (e.g. osteoporosis, anaemia, neuropathy, and night blindness). Definitive diagnosis is difficult, requiring a properly collected and appropriately cultured aspirate from the proximal small intestine revealing a total concentration of a mixed growth of bacteria generally greater than 105 organisms/ml. Alternative investigations frequently used include glucose/lactulose breath tests or either the 13C- or 14C-xylose breath test, with elevated levels of 13CO2 or 14CO2 found in the breath. There may be low levels of cobalamin (metabolized by Gram-negative anaerobes), increased serum folate (synthesized by overgrowth flora), and increased urinary indicans (intraluminal product of bacterial tryptophan metabolism). Aside from treatment of any nutritional deficiencies, specific treatment is with an antimicrobial that is effective against both aerobic and anaerobic enteric bacteria (e.g. doxycycline, amoxicillin–clavulanic acid, rifaximin, or ciprofloxacin), which can be administered in rotation to reduce antibiotic resistance. Where possible and appropriate, correction of any underlying cause should also be performed.","PeriodicalId":347739,"journal":{"name":"Oxford Textbook of Medicine","volume":"388 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123514158","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Dermatitis/eczema","authors":"P. Friedmann, Michael J. Arden-Jones, R. Hay","doi":"10.1093/med/9780198746690.003.0555","DOIUrl":"https://doi.org/10.1093/med/9780198746690.003.0555","url":null,"abstract":"Eczema is a characteristic pattern of skin inflammation that has many subtypes, with some induced by external factors such as irritants or skin sensitizers. Atopic eczema is due partly to a genetic susceptibility, which programmes altered immune responses and skin physiology, together with reactions to exogenous allergens and microbes, but several eczema patterns do not appear to have external causes. Management requires identification and avoidance of provoking factors. The inflammation is treated with topical steroids of different potencies, supplemented with moisturizers. Newer therapies include topical calcineurin antagonists, with a range of systemic therapies being used to control the most severe types of disease.","PeriodicalId":347739,"journal":{"name":"Oxford Textbook of Medicine","volume":"272 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125261502","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Obesity","authors":"I. Farooqi","doi":"10.1093/med/9780198746690.003.0223","DOIUrl":"https://doi.org/10.1093/med/9780198746690.003.0223","url":null,"abstract":"Obesity is defined as an excess of body fat that is sufficient to affect health adversely. While the quantification of fat mass is usually only performed in the research setting, body mass index (weight in kg/height in metres2) is a useful surrogate marker for fat mass. Using the World Health Organization definition of a body mass index more than 30 kg/m2 to define obesity, 30% of Americans and 10–20% of Europeans are classified as obese, with the prevalence rising in many developing countries. As body mass index increases, so does the relative risk of type 2 diabetes, hypertension, and cardiovascular disease. As such, obesity is associated with disability, mortality, and substantial health costs. At an individual level, severe obesity can be associated with sleep disturbance and respiratory difficulties, joint and mobility disorders, as well as considerable social stigma which can affect quality of life, educational attainment, and employment opportunities.","PeriodicalId":347739,"journal":{"name":"Oxford Textbook of Medicine","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125309693","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Tetanus","authors":"C. Thwaites, L. Yen","doi":"10.1093/med/9780198746690.003.0127","DOIUrl":"https://doi.org/10.1093/med/9780198746690.003.0127","url":null,"abstract":"\u0000 Clostridium tetani is a Gram-positive spore-forming anaerobic bacillus able to infect and cause disease in both humans and animals. The bacterium is highly sensitive to oxygen but can survive in the environment as an extremely resistant metabolically inactive spore. Under suitable anaerobic conditions the spore germinates and the bacteria multiply, releasing a highly potent neurotoxin, tetanus toxin, which is responsible for the clinical features of tetanus. Tetanus is a disease characterized by muscle spasms caused by a toxin produced by Clostridium tetani. Without treatment mortality is high due to muscle spasms which prevent respiration or due cardiovascular system instability secondary to autonomic nervous system dysfunction. Tetanus is prevented by good wound hygiene and/or vaccination and, although rare in developed countries, the disease remains a significant problem in many countries where facilities for treatment are often poor and mortality remains high.","PeriodicalId":347739,"journal":{"name":"Oxford Textbook of Medicine","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122347510","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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