Iodine deficiency is a lack of the trace element iodine, an essential nutrient in the diet. It may result in metabolic problems such as goiter, sometimes as an endemic goiter as well as congenital iodine deficiency syndrome due to untreated congenital hypothyroidism, which results in developmental delays and other health problems. Iodine deficiency is an important global health issue, especially for fertile and pregnant women. It is also a preventable cause of intellectual disability. Iodine is an essential dietary mineral for neurodevelopment among children. The thyroid hormones thyroxine and triiodothyronine contain iodine. In areas where there is little iodine in the diet, typically remote inland areas where no marine foods are eaten, iodine deficiency is common. It is also common in mountainous regions of the world where food is grown in iodine-poor soil. Prevention includes adding small amounts of iodine to table salt, a product known as iodized salt. Iodine compounds have also been added to other foodstuffs, such as flour, water and milk, in areas of deficiency. Seafood is also a well known source of iodine.In the U.S., the use of iodine has decreased over concerns of overdoses since mid-20th century, and the iodine antagonists bromine, perchlorate and fluoride have become more ubiquitous. In particular, around 1980 the practice of using potassium iodate as dough conditioner in bread and baked goods was gradually replaced by the use of other conditioning agents such as bromide.Iodine deficiency resulting in goiter occurs in 187 million people globally as of 2010 (2.7% of the population).
Prognosis
The disease prognosis includes:

Spread of infection to other areas of body can occur through the bloodstream (bacteremia), including septic arthritis. Glomerulonephritis can follow an episode of streptococcal erysipelas or other skin infection, but not rheumatic fever. Recurrence of infection: Erysipelas can recur in 18–30% of cases even after antibiotic treatment. A chronic state of recurrent erysipelas infections can occur with several predisposing factors including alcoholism, diabetes, and athletes foot. Another predisposing factor is chronic cutaneous edema, such as can in turn be caused by venous insufficiency or heart failure. Lymphatic damage
Necrotizing fasciitis, commonly known as "flesh-eating" bacterial infection, is a potentially deadly exacerbation of the infection if it spreads to deeper tissue. Epidemiology
There is currently no validated recent data on the worldwide incidence of erysipelas. From 2004 to 2005, UK hospitals reported 69,576 cases of cellulitis and 516 cases of erysipelas. One book stated that several studies have placed the prevalence rate between one and 250 in every 10,000 people. The development of antibiotics, as well as increased sanitation standards, has contributed to the decreased rate of incidence. Erysipelas caused systemic illness in up to 40% of cases reported by UK hospitals and 29% of people had recurrent episodes within three years. Anyone can be infected, although incidence rates are higher in infants and elderly. Several studies also reported a higher incidence rate in women.