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| '''Wajeeha Aiman M.D.''' | | '''Wajeeha Aiman, M.D.''' |
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| {{Scurvy}}
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| {{CMG}}; {{AE}}
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| ==Overview==
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| '''Scurvy''' is a chronic [[deficiency disease]] of [[vitamin C]], which is necessary for normal [[collagen]] formation in humans. L-ascorbic acid, the scientific name for vitamin c, is derived from the Latin name, scorbutus. Early symptoms of this disease are fatigue, weakness, and sore arms and legs. Without treatment, changes in [[hair]], [[skin]], and [[gums]] occur. <ref name="pmid25983516">{{cite journal| author=Agarwal A, Shaharyar A, Kumar A, Bhat MS, Mishra M| title=Scurvy in pediatric age group - A disease often forgotten? | journal=J Clin Orthop Trauma | year= 2015 | volume= 6 | issue= 2 | pages= 101-7 | pmid=25983516 | doi=10.1016/j.jcot.2014.12.003 | pmc=4411344 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=25983516 }} </ref> As scurvy worsens there can be [[personality changes]], poor [[wound healing]] and ultimately leading to death due to [[bleeding]] or [[infection]]. <ref name="pmid"Vitamin C". Office of Dietary Supplements. journal=Biochem Pharmacol | year= 1975 | volume= 24 | issue= 18 | pages= 1651-8 | pmid="Vitamin C". Office of Dietary Supplements.
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| Previously, this disease was common among pirates, sailors, and all others who were separated from the resources of vitamin c e.g. [[fruits]] and [[vegetables]] for extended periods. It takes a month with low or no vitamin c to cause symptoms.
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| In infants, scurvy is sometimes referred to as '''Barlow's disease''', named after Sir Thomas Barlow (1845–1945), <ref name="pmid6423046">{{cite journal| author=Evans PR| title=Infantile scurvy: the centenary of Barlow's disease. | journal=Br Med J (Clin Res Ed) | year= 1983 | volume= 287 | issue= 6408 | pages= 1862-3 | pmid=6423046 | doi=10.1136/bmj.287.6408.1862 | pmc=1550031 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=6423046 }} </ref> a British [[physician]] who described it. Other eponyms include '''Moeller's disease''' and '''Cheadle's disease'''. In the modern world, scurvy rarely presents in adults, infants and elderly are affected more.
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| Vitamin C, a [[water soluble]] vitamin, can easily be destroyed by [[pasteurization]]. So bottle-fed babies, not supplemented with adequate vitamins, can easily develop scurvy. For this reason, vitamin C is added to all approved baby formulas. If mothers take an adequate amount of vitamin C, then [[breast milk]] is sufficient for the babies need of this vitamin.
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| ==Pathophysiology==
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| === Physiology ===
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| Vitamins are very important for the formation and normal functioning of [[enzymes]] that are responsible for multiple processes in the human body.<ref name="pmidPrice, Catherine (2017). "The Age of Scurvy". Dist">{{cite journal| author=Ehrhart IC, Parker PE, Weidner WJ, Dabney JM, Scott JB, Haddy FJ| title=Coronary vascular and myocardial responses to carotid body stimulation in the dog. | journal=Am J Physiol | year= 1975 | volume= 229 | issue= 3 | pages= 754-60 | pmid=Price, Catherine (2017). "The Age of Scurvy". Dist | doi=10.1152/ajplegacy.1975.229.3.754 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=2017 }} </ref> [[Ascorbic acid]] is necessary for accelerating [[amidation]] reactions and [[hydroxylation]] in normal collagen synthesis. The hydroxylation of [[lysine]] and [[proline]] residues occurs in [[endoplasmic reticulum]] and leads to [[hydroxylysine]] and [[hydroxyproline]], respectively. Enzymes responsible for these reactions are [[lysyl hydroxylase]] and [[prolyl hydroxylase]]. For healthy skin, bone, muscles, [[cartilage]], blood vessels, and other connective tissues, the primary structure [[collagen]] protein is required with a proper synthesis and normal functioning.
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| === Pathogenesis ===
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| Defective collagen leads to abnormalities in all connective tissue areas. In blood vessels, defective connective tissue leads to fragile capillaries and causes bruising, abnormal bleeding, and internal hemorrhages. Similarly, teeth loosen, bones are easily breakable, recurrence of fractures, and poor wound healing. Scurvy is fatal if left untreated.
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| ==Genetics==
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| Scurvy is not a nutritional disorder exclusively. Some studies have shown evidence of genetic involvement. In the recent European history, the geographic variability of the higher mortality rate during famine and scurvy episodes can be explained by the genetic polymorphism of HFE and haptoglobin (Hp). HFE gene mutations occur in a genetic disorder, hereditary hemochromatosis, predominantly affects men and causes iron overload with a reduction in the stability of vitamin C. Hemochromatosis is associated with mutations in C282Y and H63D. <ref name="pmid24036531">{{cite journal| author=Delanghe JR, De Buyzere ML, Speeckaert MM, Langlois MR| title=Genetic aspects of scurvy and the European famine of 1845-1848. | journal=Nutrients | year= 2013 | volume= 5 | issue= 9 | pages= 3582-8 | pmid=24036531 | doi=10.3390/nu5093582 | pmc=3798922 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=24036531 }} </ref>
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| Hypoascorbemia is the true genetic disease defined as an "inborn error of metabolism", due to the absence of an active liver enzyme, L-gluconolactone oxidase. This is the enzyme used in the final step of converting glucose to ascorbic acid, therefore it blocks the endogenous formation of this important vitamin in man. <ref name="pmid6002772">{{cite journal| author=Stone I| title=Hypoascorbemia, the genetic disease causing the human requirement for exogenous ascorbic acid. | journal=Perspect Biol Med | year= 1966 | volume= 10 | issue= 1 | pages= 133-4 | pmid=6002772 | doi=10.1353/pbm.1966.0037 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=6002772 }} </ref> The absence of this enzyme is due to defected gene or hereditary lack of the gene. This disease is similar to other genetic metabolic disorders like alkaptonuria, galactosemia, albinism, and many others. <ref name="pmid5971711">{{cite journal| author=Stone I| title=On the genetic etiology of scurvy. | journal=Acta Genet Med Gemellol (Roma) | year= 1966 | volume= 15 | issue= 4 | pages= 345-50 | pmid=5971711 | doi=10.1017/s1120962300014931 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=5971711 }} </ref>
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| ==Associated Conditions==
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| Scurvy is associated with many nutritional deficiencies. <ref name="pmidhttps://pubmed.ncbi.nlm.nih.gov/6074157">{{cite journal| author=Davies IJ, Temperley JM| title=A case of scurvy in a student. | journal=Postgrad Med J | year= 1967 | volume= 43 | issue= 502 | pages= 549-50 | pmid=https://pubmed.ncbi.nlm.nih.gov/6074157 | doi=10.1136/pgmj.43.502.539 | pmc=2466190 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=6074157 }} </ref> <ref name="pmid18854467">{{cite journal| author=Léger D| title=Scurvy: reemergence of nutritional deficiencies. | journal=Can Fam Physician | year= 2008 | volume= 54 | issue= 10 | pages= 1403-6 | pmid=18854467 | doi= | pmc=2567249 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=18854467 }} </ref>
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| *[[Malnutrition]]
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| *[[Pellagra]]
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| *[[Beriberi]]
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| *Alcohol abuse
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| *Restricted diet due to allergies or any other cause
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| *[[Crohn's Disease]]
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| *[[Ulcerative colitis]]
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| *[[Celiac disease]]
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| *Smoking and other illicit drugs use
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| *[[Hemochromatosis]]
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| *[[Chemotherapy]]
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| ==Gross Pathology==
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| Lack of vitamin C leads to dermatological changes like gingival swelling, poor wound healing, ecchymosis, petechiae, loose teeth, and hyperkeratosis. Nails show koilonychia and splinter hemorrhages. Lower extremities can develop "woody edema" due to gravity dependency. Rheumatological findings are hemarthrosis and subperiosteal hemorrhage. Osseous pathology with distorted endochondral bone formation leads to fragile bones causing fractures. Ocular symptoms like dry eyes, scleral icterus, and subconjunctival hemorrhages can also occur. Alopecia and bleeding is also common. <ref name="pmid30479485">{{cite journal| author=Callus CA, Vella S, Ferry P| title=Scurvy is Back. | journal=Nutr Metab Insights | year= 2018 | volume= 11 | issue= | pages= 1178638818809097 | pmid=30479485 | doi=10.1177/1178638818809097 | pmc=6249652 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=30479485 }} </ref>
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| ==Microscopic Pathology==
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| Microscopically, it is similar to clinical manifestations. On punch biopsy, scurvy shows dilated hair follicles, perifollicular hemorrhage without inflammation, and [[corkscrew hairs]] causing keratin plugging. <ref name="pmid30422823">{{cite journal| author=Byard RW, Maxwell-Stewart H| title=Scurvy-Characteristic Features and Forensic Issues. | journal=Am J Forensic Med Pathol | year= 2019 | volume= 40 | issue= 1 | pages= 43-46 | pmid=30422823 | doi=10.1097/PAF.0000000000000442 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=30422823 }} </ref>
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| Fundoscopy shows papilledema, cotton wool spots and flame hemorrhages, retrobulbar bleeding can also occur. <ref name="pmidPMID: 29630239.">{{cite journal| author=| title=StatPearls | journal= | year= 2020 | volume= | issue= | pages= | pmid=PMID: 29630239. | doi= | pmc= | url= }} </ref>
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| ==References==
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