Impetigo is a contagious bacterial infection of the skin. It primarily afflicts children and the elderly. Ecthyma is a more severe form of impetigo with sores affecting a deeper layer of the skin. It often leaves scarring and discoloration of the skin.
The first sign of impetigo is a clear, fluid-filled bump, called a vesicle, which appears on the skin. The vesicle soon dries out and develops a scab-like, honey-colored crust, which breaks open and leaks fluid. These vesicles usually appear grouped closely together, and they may spread out and cover a large area of the skin.
Impetigo often affects the area around the nose and mouth; however, it can spread to anywhere on the skin, but especially the arms and legs, as well as the diaper areas of infants. The condition called ecthyma is a form of impetigo in which the sores that develop are larger, filled with pus, and covered with brownish-black scabs that may lead to scarring. Impetigo infections most commonly occur during warmer weather.
Causes and symptoms
Impetigo is most frequently caused by the bacteria Staphylococcus aureus, also known as “staph,” and less frequently, by group A beta-hemolytic streptococci, also known as “strep.” These bacteria are highly contagious. Impetigo can quickly spread from one part of the body to another through scratching.
It can also be spread to other people if they touch the infected sores or if they have contact with the soiled clothing, diapers, bed sheets, or toys of an infected person. Such factors as heat, humidity, crowded conditions, and poor hygiene increase the chance that impetigo will spread rapidly among large groups.
Impetigo tends to develop in areas of the skin that have already been damaged through some other means such as injury, insect bite, sunburn, diaper rash, chicken pox, or herpes, especially oral herpes. The sores tend to be very itchy, and scratching may lead to the spread of the disease. Keeping the hands washed with antibacterial soap and fingernails well trimmed are good precautions for limiting further infection.
Observation of the appearance, location and pattern of sores is the usual method of diagnosis. Fluid from the vesicles can be cultured and examined to identify the causative bacteria.
Echinacea tincture can be applied directly to the skin. The homeopathic remedy Antimonium tartaricum can be used when impetigo affects the face.
Bag Balm, an anti-bacterial salve, can be applied to sores to relieve pain and heal the skin.
A tincture of the pansy flower, Viola tricolor, can be taken internally twice daily for a week to speed healing.
Burdock root oil can be directly applied to the skin to help it heal.
Topical washes with goldenseal, grapefruit seed extract (which may sting), or tea tree oil are also recommended.
Uncomplicated impetigo is usually treated with a topical antibiotic cream such as mupirocin (Bactroban). Oral antibiotics are also commonly prescribed. Patients are advised to wash the affected areas with an antibacterial soap and water several times per day, and to otherwise keep the skin dry.
Scratching is discouraged, and the suggestion is that nails be cut or that mittens be worn—especiallly with young children. Ecthyma is treated in the same manner, but at times may require surgical debridement, or removal of the affected area.
The vast majority of those with impetigo recover quickly, completely, and uneventfully. However, there is a chance of developing a serious disease, or sequela, especially if the infection is left untreated.
Local spread of the infection can cause osteomyelitis, septic arthritis, cellulitis, or lymphangitis. If large quantities of the bacteria begin to circulate in the bloodstream, there is also a danger of developing a systemic infection such as glomerulonephritis or pneumonia.
Prevention of impetigo involves good hygiene. In order to avoid spreading the infection from one person to another, those with impetigo should be isolated until all sores are healed, and their used linen, clothing, and toys should be kept out of contact with others.