Impetigo is a bacterial infection involving superficial skin. The most common presentations are yellowish crumbs on the face, arms, or legs. Less commonly there may be a large blister affecting the groin or armpits. Lesions may be painful or itchy. Fever is rare.
This is usually due to either Staphylococcus aureus or Streptococcus pyogenes . Risk factors include attending custody, crowds, malnutrition, diabetes mellitus, contact sports, and resting on the skin such as from mosquito bites, eczema, scabies, or herpes. With contacts it can spread around or among people. Diagnosis is usually based on symptoms.
Prevention is by washing hands, avoiding infected people, and cleaning the wound. Treatment is usually with an antibiotic cream such as mupirocin or fusidic acid. Oral antibiotics, such as cephalexin, can be used if large areas are affected. Antibiotic resistant forms have been found.
Impetigo affects about 140 million people (2% of the world's population) in 2010. It can occur at any age, but is most common in children. In some places this condition is also known as "school wound". Without treatment people usually get better within three weeks. Complications may include cellulitis or poststreptococcal glomerulonephritis. Its name is from Latin impetere which means "attack".
Video Impetigo
Signs and symptoms
Infectious impetigo
This most common form of impetigo, also called nonbullous impetigo, most commonly begins as a red wound near the nose or mouth that breaks immediately, leaking pussy or fluid, and forming a honey-colored scab, followed by a red mark that heals without leaving a scar. The wound does not hurt, but it may be itchy. Lymph nodes in the affected area may be swollen, but fever is rare. Touching or scratching the wound can easily spread the infection to other parts of the body.
Skin ulcers with redness and scar can also occur due to scratching or degrading of the skin.
Bullous impetigo
Bullous impetigo, especially seen in children younger than 2 years, involves fluid-filled blisters, mostly on the arms, legs, and stems, surrounded by red and itchy skin (but not painful). Blisters may be large or small. After they break up, they form yellow scabs.
Ecthyma
Ecthyma, a nonbullous form of impetigo, produces painful injuries or pus with redness of the skin, usually on the arms and legs, into ulcers that penetrate deeper into the dermis. Once opened, they form a hard, thick, yellowish-gray scab, which sometimes leaves marks. Ecthyma may be accompanied by swollen lymph nodes in the affected area.
Maps Impetigo
Cause
Impetigo is primarily caused by Staphylococcus aureus , and occasionally by Streptococcus pyogenes . Both bullous and nonbullous are mainly caused by S. aureus , with Streptococcus also usually involved in nonbullous forms.
Predisposing factors
Impetigo is more likely to infect 2-5 year olds, especially those attending school or child care. 70% of the cases are nonbullous and 30% are bullous. Other factors may increase the risk of contracting impetigo such as diabetes mellitus, dermatitis, immunodeficiency disorders, and other irritable skin disorders. Impetigo occurs more frequently among people who live in warm climates.
Transmission
The infection spreads through direct contact with the lesion or with the carrier of the nose. The incubation period is 1-3 days after exposure to Streptococcus and 4-10 days for Staphylococcus . Dry streptococci in the air does not spread to intact skin. Scratching can spread the lesion.
Diagnosis
Impetigo is usually diagnosed by appearance. Usually appear honey scabs formed from dry serum, and often found on the arms, legs, or face. If the visual diagnosis is not clear, a culture can be performed to test for resistant bacteria.
Differential diagnosis
Other conditions that can produce symptoms similar to common forms include contact dermatitis, herpes simplex virus, discoid lupus, and scabies.
Other conditions that can cause symptoms similar to blister form include other bullous skin disease, burns, and necrotizing fasciitis.
Prevention
To prevent the spread of impetigo to other people's skin and any open wounds should be kept clean. Care should be taken to keep fluids from infected persons away from the skin of uninfected persons. Washing hands, linen, and affected areas will decrease the likelihood of contact with the infected fluid. The wound should be covered with a bandage. Scratching can spread the wound; keeping the nails short will reduce the possibility of spreading. An infected person should avoid contact with others and eliminate sharing of clothes or linens.
Treatment
Antibiotics, either as cream or by mouth, are usually prescribed. Mild cases can be treated with mupirocin ointment. In 95% of cases, only one antibiotic produces resolution in children. It has been suggested that topical antiseptics are not as efficient as antibiotics, and should therefore be avoided.
More severe cases require oral antibiotics, such as dicloxacillin, flucloxacillin, or erythromycin. Alternatively, amoxicillin is combined with potassium clavulanate, cephalosporin (first generation) and many others can also be used as antibiotic treatment. Alternatives for people who are allergic to penicillin or infection with MRSA include doxycycline, clindamycin, and SMX-TMP. When streptococci alone causes it, penicillin is the drug of choice.
When conditions present with ulcers, valacyclovir, antiviral, may be given in cases of viral infections that cause ulcers.
Alternative medicine
There is not enough evidence to recommend alternative remedies such as tea tree oil or honey.
Prognosis
Without treatment people usually get better within three weeks. Complications may include cellulitis or poststreptococcal glomerulonephritis. Rheumatic fever does not seem to be related.
Epidemiology
Globally, impetigo affects more than 162 million children in low to middle income countries. This figure is highest in countries with low available resources and is particularly prevalent in the Oceania region. The tropical climate and high population in low socioeconomic regions contribute to this high level. Children under 4 years of age in the United Kingdom are 2.8% more likely than average for impetigo contracts; this decreased to 1.6% for children up to 15 years. As we age, impetigo rates fall, but all ages are still vulnerable.
History
Impetigo was originally described and differentiated by William Tilbury Fox. The word "impetigo" is a generic Latin word for "skin eruption", and comes from the verb impetere , "to attack" (as in "impulse"). For several generations, the disease is treated with the application of antiseptic violet gentian.
References
External links
- Impetigo in Curlie (based on DMOZ)
- Impetigo and Ecthyma in Merck Manual Diagnosis and Therapy Professional Edition
Source of the article : Wikipedia
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