Causes, incidence, and risk factors: Ecthyma is most often caused by the bacteria streptococcus. Sometimes, staphylococcus bacteria causes this skin infection.
The infection may start in skin that has been injured due to a scratch or insect bite. It often develops on the legs.
The infection may first appear with a pus-filled blister, similar to that seen in persons with impetigo. However, the infection spreads much deeper into the skin.
Symptoms: The main symptom of ecthyma is a small blister with a red border that may be filled with pus. After the blister goes away, a crusty ulcer appears.
Signs and tests: Your doctor can usually diagnose this condition simply by looking at your skin. In rare cases, the fluid inside the blister may be sent to a lab for closer examination or a skin biopsy may be done.
Treatment: Your doctor will usually prescribe antibiotics.
Placing a warm wet cloth over the area can help remove ulcer crusts. Your doctor may recommend antiseptic soap or peroxide washes to speed recovery.
Expectations (prognosis): Unlike impetigo, ecthyma can sometimes result in scarring.
Complications: - Spread of infection to other parts of the body
- Permanent skin damage with scarring
Calling your health care provider: Make an appointment with your health care provider if you have symptoms of ecthyma.
Prevention: Carefully clean the skin after an injury (such as a bite or scratch). Avoid scratching or digging at scabs and sores.
References: Habif TP. Clinical Dermatology. 4th ed. St. Louis, Mo: Mosby; 2004.
Mandell GL, Bennett JE, Dolin R. Principles and Practice of Infectious Diseases. 6th ed. London: Churchill Livingstone; 2005.
Rakel RE. Textbook of Family Practice. 6th ed. Philadelphia, Pa: WB Saunders; 2002.
