What is it?
Impetigo is a contagious bacterial skin infection that affects about 2% of the population a year and is most common among preschoolers. Impetigo often begins with a red sore near the nose-mouth area, which breaks leaking pus or fluid and then forms a yellowish scab. When the scab dries it leaves a red mark, which rarely leaves a scar. Sores are not painful but can be itchy. Without treatment, Impetigo usually heals within a few weeks and, with treatment, it can be cleared up in 7 to 10 days.
What causes it?
Impetigo is caused by two kinds of bacteria. Both types can exist harmlessly on skin, and only cause infection when the skin is injured. In adults, this is usually due to another skin condition such as skin inflammation – in children, infections after a cut, scrape, insect bite, or even no apparent reason are common. Impetigo spreads effectively through both direct skin contact and through materials the infected person has been in contact with, such as bed linen and clothing.
Predisposing factors include young age (because of a not fully developed immune system or spending time in places where infection is more likely), living in a warm and humid environment, having diabetes, and having a weak immune system.
What happens during it?
Fibronectin is a glycoprotein found outside the cells whose functions include helping with cell adhesion. Cells have receptors that attach to extracellular molecules like fibronectin: this is necessary for “hooking” a multicellular organism in place and for providing the cell with information about its surroundings. The bacteria that cause Impetigo need fibronectin receptors in order to infect a person and, since these receptors can’t be found on the surface of the skin, injury to the skin is necessary for contraction.
Symptoms appear because the bacteria produce a toxin that attaches to fibronectin receptors and disrupts cell attachment. As soon as the toxin has begun to do it’s damage, the bacteria are able to spread rapidly.
How can it be treated?
Generally, Impetigo is easy to treat. Mild cases can be handled by cleansing the skin, removing the crusts, and applying antibiotic products to the skin. More severe or widespread cases are treated with oral antibiotics.
Sources: http://www.lucianoschiazza.it/documenti/impetigine_eng.html, https://en.wikipedia.org/wiki/Impetigo, http://www.nhs.uk/Conditions/Impetigo/Pages/Causes-old.aspx, http://www.medicalnewstoday.com/articles/162945.php, http://emedicine.medscape.com/article/965254-overview#a3, https://en.wikipedia.org/wiki/Fibronectin