Human breast milk contains sufficient vitamin C, if the mother has an adequate intake. Commercial milk is pasteurized, a heating process that destroys the natural vitamin C content of the milk.Scurvy is one of the accompanying diseases of malnutrition (other such micronutrient deficiencies are beriberi and pellagra) and thus is still widespread in areas of the world depending on external food aid. Although rare, there are also documented cases of scurvy due to poor dietary choices by people living in industrialized nations. Pathogenesis
Vitamins are essential to the production and use of enzymes that are involved in ongoing processes throughout the human body. Ascorbic acid is needed for a variety of biosynthetic pathways, by accelerating hydroxylation and amidation reactions. In the synthesis of collagen, ascorbic acid is required as a cofactor for prolyl hydroxylase and lysyl hydroxylase. These two enzymes are responsible for the hydroxylation of the proline and lysine amino acids in collagen. Hydroxyproline and hydroxylysine are important for stabilizing collagen by cross-linking the propeptides in collagen. Collagen is a primary structural protein in the human body, necessary for healthy blood vessels, muscle, skin, bone, cartilage, and other connective tissues. Defective connective tissue leads to fragile capillaries, resulting in abnormal bleeding, bruising, and internal hemorrhaging. Collagen is an important part of bone, so bone formation is also affected. Teeth loosen, bones break more easily, and once-healed breaks may recur. Defective collagen fibrillogenesis impairs wound healing. Untreated scurvy is invariably fatal. Diagnosis
Diagnosis is typically based on physical signs, X-rays, and improvement after treatment.
Prognosis
Children infected with roseola generally have a good prognosis. Most recover without intervention and without long-term effects. Epidemiology
Between the two types of human herpesvirus 6, HHV-6B has been detected much more frequently in hosts. HHV-6B has been shown to affect about 90% of children before the age of 3. Out of these, 20% develop symptoms of roseola, also known as exanthem subitum.Roseola affects girls and boys equally worldwide year-round. Roseola typically affects children between six months and two years of age, with peak prevalence in children between 7 and 13 months old. This correlates with the decrease in maternal antibodies, thus virus protection, that occurs at the age of 6 months. Out of all emergency department visits for children between the ages of 6 months and 12 months who have fever, twenty percent of these are due to HHV-6.Many children who have been exposed and infected can present without symptoms, which makes determining the incidence within the population difficult. History
John Zahorsky MD wrote extensively on this disease in the early 20th century, his first formal presentation was to the St Louis Pediatric society in 1909 where he described 15 young children with the illness. In a JAMA article published on Oct 18, 1913 he noted that "the name Roseola infantilis had an important place in the medical terminology of writers on skin diseases" but that descriptions of the disease by previous writers tended to confuse it with many other diseases that produce febrile rashes.