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.This type of skin lesion was first described in association with Pseudomonas aeruginosa by L. Barker in 1897. It was given the name "ecthyma gangrenosum" by Hitschmann and Kreibich.It mostly occurs in patients with underlying immunocompromise (e.g. malignancy or HIV). Although most cases are due to Pseudomonas aeruginosa infection, there are recent reports of this skin lesion in association with other microorganisms, such as Escherichia coli, Citrobacter freundii, Klebsiella pneumoniae, various other Pseudomonas species, and Morganella morganii. Signs and symptoms
The primary skin lesion usually starts with a macule that is painless, round and erythematous. Then, it develops into a pustule, and then a bulla with central hemorrhagic focus. The bulla progresses into an ulcer which extends laterally. Finally it becomes a gangrenous ulcer with a central black eschar surrounded by an erythematous halo.The lesions may be single or multiple. They are most commonly seen in perineum and under arm pit. However, they can occur in any part of the body. Mechanism
The organism enters directly through the breakdown of mechanical defense barriers such as mucosa or skin.
Depending on the causal agents, antivirals or antifungals can be added.Surgery will be needed if there is extensive necrosis not responding to medical treatments. Recent research
A recent retrospective study of all cases of ecthyma gangrenosum from 2004 to 2010 in a university hospital in Mexico shows that neutropenia in immunocompromised patients is the most common risk factor for ecthyma gangrenosum. References


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