Impetigo, commonly known as school sores, is a bacterial skin infection. It is characterized by itchy, red sores and/or blisters that may pop to produce a yellow-to-brown crust. Although impetigo can occur in anyone, it usually affects children between 2-6 years of age. It can develop anywhere on the body, but is most common around the mouth and nose.
Impetigo is caused by infection of the skin due to Streptococcus pyogenes and/or Staphylococcus aureus bacteria. Sometimes, Streptococcus pyogenes bacteria is also known as Group A Streptococcus bacteria (GAS) or group A beta-hemolytic streptococcus (GABHS). In recent times, a strain of the bacteria called methicillin-resistant Staphylococcus aureus (MRSA) has become a common cause of impetigo. The term 'methicillin-resistant' means that these bacteria are no longer destroyed by penicillin-based antibiotics, which are a common therapy for bacterial skin infections. These bacteria can live on the skin and in the nose without causing any harm. Impetigo generally occurs when the bacteria get past the skin's natural barrier, usually through a break in the skin. Common causes for skin damage are insect bites, cuts and scratches, and other skin conditions, such as eczema, head lice or scabies. However, impetigo can also affect healthy skin that has no obvious signs of damage.
Once the bacteria enter through skin breaks, it causes localized inflammation in the top layers of the skin. This leads to the characteristic symptoms of red sores, fluid-filled blisters, and crusting on the skin.
Impetigo is easily spread through direct contact with an infected person. Sores and fluid from the nose and throat contain large numbers of Streptococcus pyogenes and/or Staphylococcus aureus bacteria. These can be spread to other areas of the body or another person by scratching and touching the sores.
Healthy skin compared to skin infected with impetigo.
Risk factors that may increase the likelihood of developing impetigo include:
A metabolic disorder that is caused by problems with insulin secretion and regulation and which is characterized by high blood sugar levels. Also known as diabetes mellitus.
There are two types of impetigo:
Also known as vesiculopustular impetigo, this type of infection may be caused by either Streptococcus pyogenes or Staphylococcus aureus bacteria. Non-bullous impetigo is characterized by red sores that quickly form ulcers and then produce a yellow-to-brown crust a few days later. A red mark may also appear after crusting, which can take a few days or weeks to clear.
Bullous impetigo is caused by Staphylococcus aureus bacteria. It is less common, but more contagious than the non-bullous type. The name originates from the medical word, 'bulla', which means a large, fluid-filled blister. These blisters usually occur under the nappy line in babies, or on the torso, arms or legs. After several days, the blisters usually burst and then form a yellow crust. There may be accompanying symptoms of fever, swollen lymph nodes and/or unwellness.
An open sore in the skin or mucous membranes such as those of the stomach lining, intestine or mouth.
Symptoms of impetigo usually develop about 4-10 days after coming into contact with an infected person. The condition often starts with a rash of just a few spots or blisters that can spread to other areas. It may also lead to infection in other people before the condition has been identified.
In general, the signs and symptoms of impetigo include:
Rarely, there can be accompanying symptoms of fever, swollen lymph nodes and feeling of unwellness.
Impetigo sores around the mouth and nose.
Your doctor will most likely diagnose impetigo by looking closely at your skin and asking questions about symptoms.
If symptoms don't respond to treatment or keep coming back, your doctor may take a swab of the blisters or sores to see which bacteria are present. This can also help to determine the most appropriate antibiotics to treat the bacteria.
A swab of the infected skin to test for bacterial presence.
Impetigo is generally treated using good cleaning habits and antibiotics. Keeping children with impetigo home, is recommended to help prevent the spread of infection. It is generally advised, that they should be kept away from other children until the skin is completely healed.
The treatment may vary with the severity of the symptoms. The doctor is likely to recommend the following:
To help prevent the spread of infection, it is important to practice regular hand-washing. Also, treating affected areas of skin with an antibacterial solution, such as chlorhexidine or povidone-iodine, can further reduce spread of the infection. Other skincare measures may include covering sores with a waterproof dressing and avoiding scratching. Soaking off any crusts with warm water can help the skin to better absorb antibacterial medications.
In mild cases of impetigo, your doctor may prescribe an antibiotic ointment. These are applied directly to the skin, usually three times per day for several days.
For more severe or widespread infection, an oral antibiotic may be prescribed. Some examples of oral antibiotics given for impetigo include flucloxacillin, dicloxacillin and cephalexin. These antibiotics will not be effective against methicillin-resistant Staphylococcus aureus (MRSA), which requires more tailored antibiotics.
If impetigo keeps coming back, your doctor may prescribe oral antibiotics on a long-term basis, or to use at the earliest sign of infection. For all types of antibiotic treatment, taking the full course prescribed by your doctor is important to ensure that the infection is completely cleared. Sometimes the nostrils may be treated with an antibiotic ointment, if your doctor suspects the nose to be the source of recurrent infections.
Most cases of impetigo are successfully treated with antibiotics. While impetigo can sometimes look unsightly, long-term scarring and complications are not common. Rarely, a deeper form of impetigo can develop, usually on the legs or other areas. This condition, known as ecthyma, is characterized by ulcers beneath the typical crusted sores. This condition generally requires oral antibiotics, which is continued for a longer period of time.
Impetigo can also be serious in newborn babies, as their immune systems may not be able to recognize and fight a bacterial infection effectively. If symptoms appear on your newborn baby, seek prompt medical attention.
Impetigo can occasionally recur, especially if not adequately treated. In rare cases, if left untreated, the infection can spread to other areas and result in:
In very rare cases, impetigo can lead to scarring. However, this mainly occurs due to excessive scratching of the affected skin.
The organs and cells involved in protecting the body against infection.
An illness caused by inflammation throughout the body in response to an infection. It can be life-threatening if it leads to septic shock, a dramatic loss of blood pressure.
An open sore in the skin or mucous membranes such as those of the stomach lining, intestine or mouth.
A group of conditions in which the part of the kidneys that helps filter the blood is damaged.
The outlook for impetigo is good when it's treated early with good skin-care and antibiotics as required. Although the condition may be itchy and unsightly, it generally is not painful and is unlikely to cause long-term scarring. The cure rate is high, but impetigo may come back, especially in young children.
Impetigo may be prevented by avoiding contact with people who have the condition. If contact can't be completely avoided, the likelihood of developing impetigo may be reduced by keeping the skin clean and limiting the sharing of food, drinks, bathwater, towels or other personal items. At present, there are no vaccinations to prevent this condition.