DermNet NZ

Facts about the skin from DermNet New Zealand Trust. Topic index: A B C D E F G H I J K L M N O P Q R S T U V W X Y Z


What is ecthyma?

Ecthyma is a skin infection characterised by crusted sores beneath which ulcers form. It is a deep form of impetigo as the same bacteria causing the infection are involved but ecthyma causes deeper erosions of the skin.

Streptococcus pyogenes and/or Staphylococcus aureus are the bacteria responsible for ecthyma.

Ecthyma with scarring

Who gets ecthyma?

People of all ages, sex and race can be affected, although children, elderly people and immunocompromised patients (eg diabetes, neutropenia, immunosuppressive medication, malignancy, HIV) tend to have a greater chance of infection. Other factors that increase the risk of ecthyma include:

What are the signs and symptoms?

Ecthyma lesion usually begins as a vesicle (small blister) or pustule on an inflamed area of skin. A hard crust that is harder and thicker than the crust of impetigo soon covers this. With difficulty, the crust can be removed to reveal an indurated ulcer that may be red, swollen and oozing with pus. Lesions may stay fixed in size and sometimes resolve spontaneously without treatment, or they may gradually enlarge to a sore of 0.5-3 cm in diameter.

The areas most affected are the buttocks, thighs, legs, ankle and feet. Occasionally, the local lymph nodes become swollen and painful.

What treatment is available?

Treatment depends on the extent and severity of infection. Any underlying disease or skin infection such as scabies or dermatitis should also be treated.

Another very important factor to consider in the overall management of ecthyma is to improve hygiene. Measures to take include:

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Author: Vanessa Ngan, staff writer

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If you have any concerns with your skin or its treatment, see a dermatologist for advice.