Impetigo | |
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Other names | School sores, [1] impetigo contagiosa |
A case of impetigo on the chin | |
Pronunciation | |
Specialty | Dermatology, infectious disease |
Symptoms | Yellowish skin crusts, painful [2] [3] |
Complications | Cellulitis, poststreptococcal glomerulonephritis [3] |
Usual onset | Young children [3] |
Duration | Less than 3 weeks [3] |
Causes | Staphylococcus aureus or Streptococcus pyogenes which spreads by direct contact |
Risk factors | Day care, crowding, poor nutrition, diabetes mellitus, contact sports, breaks in the skin [3] [4] |
Prevention | Hand washing, avoiding infected people, cleaning injuries [3] |
Treatment | Based on symptoms [3] |
Medication | Antibiotics (mupirocin, fusidic acid, cefalexin) [3] [5] |
Frequency | 140 million (2010) [6] |
Impetigo is a contagious bacterial infection that involves the superficial skin. [2] The most common presentation is yellowish crusts on the face, arms, or legs. [2] Less commonly there may be large blisters which affect the groin or armpits. [2] The lesions may be painful or itchy. [3] Fever is uncommon. [3]
It is typically due to either Staphylococcus aureus or Streptococcus pyogenes . [7] Risk factors include attending day care, crowding, poor nutrition, diabetes mellitus, contact sports, and breaks in the skin such as from mosquito bites, eczema, scabies, or herpes. [3] [4] With contact it can spread around or between people. [3] Diagnosis is typically based on the symptoms and appearance. [3]
Prevention is by hand washing, avoiding people who are infected, and cleaning injuries. [3] Treatment is typically with antibiotic creams such as mupirocin or fusidic acid. [3] [5] Antibiotics by mouth, such as cefalexin, may be used if large areas are affected. [3] Antibiotic-resistant forms have been found. [3] Healing generally occurs without scarring. [7]
Impetigo affected about 140 million people (2% of the world population) in 2010. [6] It can occur at any age, but is most common in young children. [3] In some places the condition is also known as "school sores". [1] Without treatment people typically get better within three weeks. [3] Recurring infections can occur due to colonization of the nose by the bacteria. [8] [9] Complications may include cellulitis or poststreptococcal glomerulonephritis. [3] The name is from the Latin impetere meaning "attack". [10]
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, [11] 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. [12]
Skin ulcers with redness and scarring also may result from scratching or abrading the skin.[ citation needed ]
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. [12]
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. [12]
Impetigo is primarily caused by Staphylococcus aureus , and sometimes by Streptococcus pyogenes . [13] Both bullous and nonbullous are primarily caused by S. aureus, with Streptococcus also commonly being involved in the nonbullous form. [14]
Impetigo is more likely to infect children ages 2–5, especially those that attend school or day care. [3] [15] [1] 70% of cases are the nonbullous form and 30% are the bullous form. [3] Impetigo occurs more frequently among people who live in warm climates. [16]
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. [17] Dried streptococci in the air are not infectious to intact skin. Scratching may spread the lesions.[ citation needed ]
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. [13] If a visual diagnosis is unclear a culture may be done to test for resistant bacteria. [18]
Other conditions that can result in symptoms similar to the common form include contact dermatitis, herpes simplex virus, discoid lupus, and scabies. [3]
Other conditions that can result in symptoms similar to the blistering form include other bullous skin diseases, burns, and necrotizing fasciitis. [3]
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. [19] Children with impetigo can return to school 24 hours after starting antibiotic therapy as long as their draining lesions are covered. [20]
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. [20] [21] It has been advocated that topical antiseptics are inferior to topical antibiotics, and therefore should not be used as a replacement. [3] 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. [22] This recommendation is part of an effort to reduce the overuse of antimicrobials that may contribute to the development of resistant organisms [23] 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. [20] 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. [24]
Without treatment, individuals with impetigo typically get better within three weeks. [3] Complications may include cellulitis or poststreptococcal glomerulonephritis. [3] Rheumatic fever does not appear to be related. [3]
Globally, impetigo affects more than 162 million children in low- to middle-income countries. [25] The rates are highest in countries with low available resources and is especially prevalent in the region of Oceania. [25] The tropical climate and high population in lower socioeconomic regions contribute to these high rates. [26] 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. [27] As age increases, the rate of impetigo declines, but all ages are still susceptible. [26]
Impetigo was originally described and differentiated by the English dermatologist William Tilbury Fox around 1864. [28] The word impetigo is the generic Latin word for 'skin eruption', and it stems from the verb impetere 'to attack' (as in impetus). [29] Before the discovery of antibiotics, the disease was treated with an application of the antiseptic gentian violet, which was an effective treatment. [30] [31]
Brain abscess is an abscess within the brain tissue caused by inflammation and collection of infected material coming from local or remote infectious sources. The infection may also be introduced through a skull fracture following a head trauma or surgical procedures. Brain abscess is usually associated with congenital heart disease in young children. It may occur at any age but is most frequent in the third decade of life.
Scarlet fever, also known as scarlatina, is an infectious disease caused by Streptococcus pyogenes, a Group A streptococcus (GAS). It most commonly affects children between five and 15 years of age. The signs and symptoms include a sore throat, fever, headache, swollen lymph nodes, and a characteristic rash. The face is flushed and the rash is red and blanching. It typically feels like sandpaper and the tongue may be red and bumpy. The rash occurs as a result of capillary damage by exotoxins produced by S.pyogenes. On darker-pigmented skin the rash may be hard to discern.
Streptococcal pharyngitis, also known as streptococcal sore throat, is pharyngitis caused by Streptococcus pyogenes, a gram-positive, group A streptococcus. Common symptoms include fever, sore throat, red tonsils, and enlarged lymph nodes in the front of the neck. A headache and nausea or vomiting may also occur. Some develop a sandpaper-like rash which is known as scarlet fever. Symptoms typically begin one to three days after exposure and last seven to ten days.
Methicillin-resistant Staphylococcus aureus (MRSA) is a group of gram-positive bacteria that are genetically distinct from other strains of Staphylococcus aureus. MRSA is responsible for several difficult-to-treat infections in humans. It caused more than 100,000 deaths worldwide attributable to antimicrobial resistance in 2019.
Pharyngitis is inflammation of the back of the throat, known as the pharynx. It typically results in a sore throat and fever. Other symptoms may include a runny nose, cough, headache, difficulty swallowing, swollen lymph nodes, and a hoarse voice. Symptoms usually last 3–5 days, but can be longer depending on cause. Complications can include sinusitis and acute otitis media. Pharyngitis is a type of upper respiratory tract infection.
An ulcer is a sore on the skin or a mucous membrane, accompanied by the disintegration of tissue. Ulcers can result in complete loss of the epidermis and often portions of the dermis and even subcutaneous fat. Ulcers are most common on the skin of the lower extremities and in the gastrointestinal tract. An ulcer that appears on the skin is often visible as an inflamed tissue with an area of reddened skin. A skin ulcer is often visible in the event of exposure to heat or cold, irritation, or a problem with blood circulation.
Chancroid is a bacterial sexually transmitted infection characterized by painful sores on the genitalia. Chancroid is known to spread from one individual to another solely through sexual contact. However, there have been reports of accidental infection through the hand.
Cellulitis is usually a bacterial infection involving the inner layers of the skin. It specifically affects the dermis and subcutaneous fat. Signs and symptoms include an area of redness which increases in size over a few days. The borders of the area of redness are generally not sharp and the skin may be swollen. While the redness often turns white when pressure is applied, this is not always the case. The area of infection is usually painful. Lymphatic vessels may occasionally be involved, and the person may have a fever and feel tired.
Tonsillitis is inflammation of the tonsils in the upper part of the throat. It can be acute or chronic. Acute tonsillitis typically has a rapid onset. Symptoms may include sore throat, fever, enlargement of the tonsils, trouble swallowing, and enlarged lymph nodes around the neck. Complications include peritonsillar abscess (quinsy).
A boil, also called a furuncle, is a deep folliculitis, which is an infection of the hair follicle. It is most commonly caused by infection by the bacterium Staphylococcus aureus, resulting in a painful swollen area on the skin caused by an accumulation of pus and dead tissue. Boils are therefore basically pus-filled nodules. Individual boils clustered together are called carbuncles. Most human infections are caused by coagulase-positive S. aureus strains, notable for the bacteria's ability to produce coagulase, an enzyme that can clot blood. Almost any organ system can be infected by S. aureus.
Dukes' disease, named after Clement Dukes (1845–1925), also known as fourth disease, Filatov-Dukes' disease, Staphylococcal Scalded Skin Syndrome (SSSS), or Ritter's disease is an exanthem (rash-causing) illness primarily affecting children and historically described as a distinct bacterial infection, though its existence as a separate disease entity is now debated.
Flucloxacillin, also known as floxacillin, is an antibiotic used to treat skin infections, external ear infections, infections of leg ulcers, diabetic foot infections, and infection of bone. It may be used together with other medications to treat pneumonia, and endocarditis. It may also be used prior to surgery to prevent Staphylococcus infections. It is not effective against methicillin-resistant Staphylococcus aureus (MRSA). It is taken by mouth or given by injection into a vein or muscle.
Gingivostomatitis is a combination of gingivitis and stomatitis, or an inflammation of the oral mucosa and gingiva. Herpetic gingivostomatitis is often the initial presentation during the first ("primary") herpes simplex infection. It is of greater severity than herpes labialis which is often the subsequent presentations. Primary herpetic gingivostomatitis is the most common viral infection of the mouth.
A skin infection is an infection of the skin in humans and other animals, that can also affect the associated soft tissues such as loose connective tissue and mucous membranes. They comprise a category of infections termed skin and skin structure infections (SSSIs), or skin and soft tissue infections (SSTIs), and acute bacterial SSSIs (ABSSSIs). They are distinguished from dermatitis, although skin infections can result in skin inflammation.
Herpes gladiatorum is one of the most infectious of herpes-caused diseases, and is transmissible by skin-to-skin contact. The disease was first described in the 1960s in the New England Journal of Medicine. It is caused by contagious infection with human herpes simplex virus type 1 (HSV-1), which more commonly causes oral herpes. Another strain, HSV-2 usually causes genital herpes, although the strains are very similar and either can cause herpes in any location.
Ecthyma gangrenosum is a type of skin lesion characterized by vesicles or blisters which rapidly evolve into pustules and necrotic ulcers with undermined tender erythematous border. "Ecthyma" means a pus forming infection of the skin with an ulcer, "gangrenosum" refers to the accompanying gangrene or necrosis. It is classically associated with Pseudomonas aeruginosa bacteremia, but it is not pathognomonic. Pseudomonas aeruginosa is a gram negative, aerobic bacillus.
A staphylococcal infection or staph infection is an infection caused by members of the Staphylococcus genus of bacteria.
Bullous impetigo is a bacterial skin infection caused by Staphylococcus aureus that results in the formation of large blisters called bullae, usually in areas with skin folds like the armpit, groin, between the fingers or toes, beneath the breast, and between the buttocks. It accounts for 30% of cases of impetigo, the other 70% being non-bullous impetigo.
Skin and skin structure infections (SSSIs), also referred to as skin and soft tissue infections (SSTIs), or acute bacterial skin and skin structure infections (ABSSSIs), are infections of skin and associated soft tissues. Historically, the pathogen involved has most frequently been a bacterial species—always, since redescription of SSSIs as ABSSSIs—and as such, these infections require treatment by antibiotics.
Professor Asha Bowen is an Australian Paediatric Infectious Diseases clinician-scientist and a leading voice and advocate for children's health and well-being. She is Head of the Department of Infectious Diseases at Perth Children's Hospital, and Head of the Healthy Skin and ARF Prevention team at Telethon Kids Institute. She was the former Program Head of the End Rheumatic Heart Disease program (2022-2023) at the Telethon Kids Institute. Bowen leads a large body of skin health research in partnership with healthcare workers and community in the Kimberley while expanding her team and work to understand skin health in urban Aboriginal children better. She has been widely acknowledged and awarded for her contributions towards improving the health and well-being of Australian children, and addressing existing health inequities faced by First Nations Australian children and their families. Throughout the COVID-19 pandemic she contributed her knowledge and expertise to clinical research, guideline development and on several national and public health committees. She has published widely in the area of paediatric infectious diseases and is a recognized expert in the field who regularly contributes to popular Australian media sources such as The Conversation.