Ecthyma is a severe bacterial infection that causes painful lesions and blisters to appear on the skin. Most cases are caused by skin exposure streptococci, but several other bacteria, including staphylococci, can also lead to symptoms. An infection typically begins as a small red ulcer that quickly blisters, hardens, and crusts over. Blisters may go away on their own over several months, but an untreated case can cause permanent scarring and spread across the skin. Doctors usually prescribe oral antibiotics at the first signs of ecthyma to promote fast healing.
When bacteria enter the skin through an open wound or insect bite, they burrow into the tissue and cause inflammation. Most infections remain in the superficial layers of skin and result in less painful and persistent blisters, a condition called impetigo. Ecthyma occurs when bacteria make their way into the deepest layers of skin tissue. Infections are usually seen on the legs, buttocks, or arms, but infection can potentially occur anywhere on the body. Developing lesions can be itchy, but doctors encourage patients not to scratch to avoid further irritation and reduce the chances of spreading bacteria to other areas of skin.
A number of genetic and environmental factors can contribute to the development of ecthyma. Many patients who are diagnosed with ecthyma have a personal history of dermatitis, eczema, and allergies. Elderly people and young children are more susceptible to infections in general due to their weak immune systems, as are adults with immunosuppressive disorders such as HIV. In addition, individuals who live in crowded areas with poor sanitation are at a higher risk of developing the condition.
A dermatologist can usually diagnose ecthyma by carefully inspecting lesions and asking about symptoms. He or she may decide to scrape a small sample of infected tissue to have it analyzed for specific bacteria. After determining the cause, the dermatologist can explain treatment and prevention measures.
Small, isolated lesions are often treated with topical antibiotics and dressed with protective bandages. If crusting is an issue, the doctor can debride the sores before applying bandages. After in-office care, the patient is usually written a prescription for penicillin or another oral antibiotic to take daily for about two weeks.
In order to prevent recurring episodes of ecthyma and spreading the infection to others, patients are educated about the importance of proper hygiene. An individual should wash healing lesions regularly with antiseptic soap, change bandages frequently, and avoid sharing towels, linens, and clothing with others. Most cases of ecthyma clear up within two to six weeks with antibiotics and home care.