Impetigo

This most common form of impetigo, also called nonbullous impetigo, most often begins as a red sore near the nose or mouth which soon breaks, leaking pus or fluid, and forms a honey-colored scab,{{cite journal | vauthors = Cole C, Gazewood J | title = Diagnosis and treatment of impetigo | journal = American Family Physician | volume = 75 | issue = 6 | pages = 859–864 | date = March 2007 | pmid = 17390597 | url = http://www.aafp.org/afp/2007/0315/p859.html | url-status = live | archive-url = https://web.archive.org/web/20150430100234/http://www.aafp.org/afp/2007/0315/p859.html | archive-date = 2015-04-30 }} followed by a red mark which often heals without leaving a scar. Sores are not painful, but they may be itchy. Lymph nodes in the affected area may be swollen, but fever is rare. Touching or scratching the sores may easily spread the infection to other parts of the body.{{cite web|url= http://semj.sums.ac.ir/vol8/jul2007/impetigo.htm|title= Impetigo|author= Mayo Clinic staff|date= 5 October 2010|work= Mayo Clinic Health Information|publisher= Mayo Clinic|access-date= 25 August 2012|url-status= dead|archive-url= https://web.archive.org/web/20121128081224/http://semj.sums.ac.ir/vol8/jul2007/impetigo.htm|archive-date= 28 November 2012}}

Skin ulcers with redness and scarring also may result from scratching or abrading the skin.{{citation needed|date=May 2020}}

{{Gallery|width=200

|File:Woman's face infected with impetigo Wellcome L0074829 (cropped).jpg|Illustration of a woman with a severe facial impetigo

|File:Impetigo-infected.jpg|Impetigo on the back of the neck

|File:Impetigo2011.jpg|A severe case of facial impetigo

}}

File:Bullous impetigo1.jpg after the bullae have broken]]

Bullous impetigo, mainly seen in children younger than two years, involves painless, fluid-filled blisters, mostly on the arms, legs, and trunk, surrounded by red and itchy (but not sore) skin. The blisters may be large or small. After they break, they form yellow scabs.

Ecthyma, the nonbullous form of impetigo, produces painful fluid- or pus-filled sores with redness of skin, usually on the arms and legs, become ulcers that penetrate deeper into the dermis. After they break open, they form hard, thick, gray-yellow scabs, which sometimes leave scars. Ecthyma may be accompanied by swollen lymph nodes in the affected area.

Impetigo is primarily caused by Staphylococcus aureus, and sometimes by Streptococcus pyogenes.{{cite book | vauthors = Kumar V, Abbas AK, Fausto N, Mitchell RN | date = 2007 | title = Robbins Basic Pathology | edition = 8th | publisher = Saunders Elsevier | page = 843 | isbn = 978-1-4160-2973-1 }} Both bullous and nonbullous are primarily caused by S. aureus, with Streptococcus also commonly being involved in the nonbullous form.{{cite journal | vauthors = Stulberg DL, Penrod MA, Blatny RA | title = Common bacterial skin infections | journal = American Family Physician | volume = 66 | issue = 1 | pages = 119–124 | date = July 2002 | pmid = 12126026 | url = http://www.aafp.org/afp/20020701/119.html | url-status = live | archive-url = https://web.archive.org/web/20070929104522/http://www.aafp.org/afp/20020701/119.html | archive-date = 2007-09-29 }}

Impetigo is more likely to infect children ages 2–5, especially those that attend school or day care.{{cite web|title=Impetigo (school sores)|url=http://www.health.govt.nz/your-health/conditions-and-treatments/diseases-and-illnesses/impetigo-school-sores|website=www.health.govt.nz|publisher=Ministry of Health|access-date=14 September 2017}} 70% of cases are the nonbullous form and 30% are the bullous form. Impetigo occurs more frequently among people who live in warm climates.{{cite book |title= Diseases of the Human Body| vauthors = Tamparo C, Lewis M |publisher=F.A. Davis Company |year=2011 |isbn=978-0-8036-2505-1 |location=Philadelphia, PA |pages=194}}

The infection is spread by direct contact with lesions or with nasal carriers. The incubation period is 1–3 days after exposure to Streptococcus and 4–10 days for Staphylococcus.{{cite web|url=http://www.state.in.us/isdh/23303.htm|title=ISDH: Impetigo|work=state.in.us|access-date=11 December 2014|url-status=dead|archive-url=https://web.archive.org/web/20141211025205/http://www.state.in.us/isdh/23303.htm|archive-date=11 December 2014}} Dried streptococci in the air are not infectious to intact skin. Scratching may spread the lesions.{{citation needed|date=May 2020}}

Impetigo is usually diagnosed based on its appearance. It generally appears as honey-colored scabs formed from dried sebum and is often found on the arms, legs, or face. If a visual diagnosis is unclear a culture may be done to test for resistant bacteria.{{cite web|title=Impetigo: MedlinePlus Medical Encyclopedia|url=https://medlineplus.gov/ency/article/000860.htm|website=medlineplus.gov|url-status=live|archive-url=https://web.archive.org/web/20161107092650/https://medlineplus.gov/ency/article/000860.htm|archive-date=2016-11-07}}

Other conditions that can result in symptoms similar to the common form include contact dermatitis, herpes simplex virus, discoid lupus, and scabies.

Other conditions that can result in symptoms similar to the blistering form include other bullous skin diseases, burns, and necrotizing fasciitis.

To prevent the spread of impetigo the skin and any open wounds should be kept clean and covered. Care should be taken to keep fluids from an infected person away from the skin of a non-infected person. Washing hands, linens, and affected areas will lower the likelihood of contact with infected fluids. Scratching can spread the sores; keeping nails short will reduce the chances of spreading. Infected people should avoid contact with others and eliminate sharing of clothing or linens.{{cite web|title=Self-management - Impetigo - Mayo Clinic|url=http://www.mayoclinic.org/diseases-conditions/impetigo/manage/ptc-20202600|website=www.mayoclinic.org|access-date=7 October 2016|url-status=live|archive-url=https://web.archive.org/web/20161016100459/http://www.mayoclinic.org/diseases-conditions/impetigo/manage/ptc-20202600|archive-date=16 October 2016}} Children with impetigo can return to school 24 hours after starting antibiotic therapy as long as their draining lesions are covered.{{Cite web |url= https://www.uptodate.com/contents/impetigo?search=impetigo&source=search_result&selectedTitle=1~119&usage_type=default&display_rank=1 |title=Impetigo| vauthors = Baddour L |website=UpToDate |access-date=2018-08-15}}

Antibiotics, either as a cream or by mouth, are usually prescribed. Mild cases may be treated with mupirocin ointments. In 95% of cases, a single seven-day antibiotic course results in resolution in children.{{cite book|url=https://books.google.com/books?id=a7CqcE1ZrFkC&q=impetigo&pg=PA925|title=Textbook of Pediatric Emergency Medicine| vauthors = Fleisher GR, Ludwig S |date=2010-01-01|publisher=Lippincott Williams & Wilkins|isbn=978-1-60547-159-4|pages=925|language=en|url-status=live|archive-url=https://web.archive.org/web/20170908221933/https://books.google.com/books?id=a7CqcE1ZrFkC&pg=PA925&dq=impetigo|archive-date=2017-09-08}} It has been advocated that topical antiseptics are inferior to topical antibiotics, and therefore should not be used as a replacement. However, the National Institute for Health and Care Excellence (NICE) as of February 2020 recommends a hydrogen peroxide 1% cream antiseptic rather than topical antibiotics for localised non-bullous impetigo in otherwise well individuals.{{cite web|access-date=2020-05-26|title=Impetigo: antimicrobial prescribing - NICE guideline [NG153]|url=https://www.nice.org.uk/guidance/ng153/chapter/Recommendations|website=www.nice.org.uk|date=26 February 2020 }} This recommendation is part of an effort to reduce the overuse of antimicrobials that may contribute to the development of resistant organisms{{cite journal | vauthors = Mahase E | title = Doctors should treat impetigo with antiseptics not antibiotics, says NICE | journal = BMJ | volume = 366 | pages = l5162 | date = August 2019 | pmid = 31416810 | doi = 10.1136/bmj.l5162 | s2cid = 201018620 }} such as MRSA.

More severe cases require oral antibiotics, such as dicloxacillin, flucloxacillin, or erythromycin. Alternatively, amoxicillin combined with clavulanate potassium, cephalosporins (first-generation) and many others may also be used as an antibiotic treatment. Alternatives for people who are seriously allergic to penicillin or infections with methicillin-resistant Staphococcus aureus include doxycycline, clindamycin, and trimethoprim-sulphamethoxazole, although doxycycline should not be used in children under the age of eight years old due to the risk of drug-induced tooth discolouration. When streptococci alone are the cause, penicillin is the drug of choice. When the condition presents with ulcers, valacyclovir, an antiviral, may be given in case a viral infection is causing the ulcer.{{cite web |title=Valacyclovir Hydrochloride Monograph for Professionals |url=https://www.drugs.com/monograph/valacyclovir-hydrochloride.html |website=Drugs.com |publisher=American Society of Health-System Pharmacists |access-date=17 March 2019 }}

Without treatment, individuals with impetigo typically get better within three weeks. Complications may include cellulitis or poststreptococcal glomerulonephritis. Rheumatic fever does not appear to be related.

Globally, impetigo affects more than 162 million children in low- to middle-income countries. The rates are highest in countries with low available resources and is especially prevalent in the region of Oceania.{{cite journal | vauthors = Bowen AC, Mahé A, Hay RJ, Andrews RM, Steer AC, Tong SY, Carapetis JR | title = The Global Epidemiology of Impetigo: A Systematic Review of the Population Prevalence of Impetigo and Pyoderma | journal = PLOS ONE | volume = 10 | issue = 8 | pages = e0136789 | date = 2015 | pmid = 26317533 | pmc = 4552802 | doi = 10.1371/journal.pone.0136789 | bibcode = 2015PLoSO..1036789B | doi-access = free }} The tropical climate and high population in lower socioeconomic regions contribute to these high rates.{{cite journal | vauthors = Romani L, Steer AC, Whitfeld MJ, Kaldor JM | title = Prevalence of scabies and impetigo worldwide: a systematic review | journal = The Lancet. Infectious Diseases | volume = 15 | issue = 8 | pages = 960–967 | date = August 2015 | pmid = 26088526 | doi = 10.1016/S1473-3099(15)00132-2 }} Children under the age of 4 in the United Kingdom are 2.8% more likely than average to contract impetigo; this decreases to 1.6% for children up to 15 years old.{{cite journal | vauthors = George A, Rubin G | title = A systematic review and meta-analysis of treatments for impetigo | journal = The British Journal of General Practice | volume = 53 | issue = 491 | pages = 480–487 | date = June 2003 | pmid = 12939895 | pmc = 1314624 }} As age increases, the rate of impetigo declines, but all ages are still susceptible.

Impetigo was originally described and differentiated by the English dermatologist William Tilbury Fox around 1864.{{cite journal |title=Impetigo |journal=The British Medical Journal |volume=1 |issue=4185 |year=1941 |pages=448 |jstor=20319413 |doi=10.1136/bmj.1.4185.445-a|s2cid=214846855 }} The word impetigo is the generic Latin word for 'skin eruption', and it stems from the verb {{Lang|la|impetere}} 'to attack' (as in impetus).{{cite book |title=The Barnhart Concise Dictionary of Etymology |publisher=Harper Collins |year=1995 |isbn=978-0-06-270084-1 }} Before the discovery of antibiotics, the disease was treated with an application of the antiseptic gentian violet, which was an effective treatment.{{cite journal | vauthors = MacDonald RS | title = Treatment of impetigo: paint it blue | journal = BMJ | volume = 329 | issue = 7472 | pages = 979 | date = October 2004 | pmid = 15499130 | pmc = 524121 | doi = 10.1136/bmj.329.7472.979 }}{{cite book

|last=Tilbury Fox

|first=William

|author-link=William Tilbury Fox

|date=1864

|title=On impetigo contagiosa, or porrigo

|url=https://archive.org/details/b22315834

|location=England

|publisher= Printed by T. Richards

}}

{{Reflist}}

• {{MerckManual|10|119|i||Impetigo and Ecthyma}}

{{Medical resources

| eMedicine_mult = {{eMedicine2|emerg|283}} {{eMedicine2|med|1163}} {{eMedicine2|ped|1172}}

| DiseasesDB = 6753

| ICD10 = {{ICD10|L|01||l|00}}

| ICD9 = {{ICD9|684}}

| ICDO =

| OMIM =

| MedlinePlus = 000860

| eMedicineSubj = derm

| eMedicineTopic = 195

| MeshID = D007169

}}

{{Diseases of the skin and appendages by morphology}}

{{Bacterial cutaneous infections}}

Category:Bacterium-related cutaneous conditions

Category:Pediatrics

Category:Wikipedia medicine articles ready to translate

Category:Wikipedia emergency medicine articles ready to translate