Ecthyma gangrenosum: Difference between revisions
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{{CMG}} | {{CMG}};{{AE}} {{KS}} | ||
==Overview== | ==Overview== | ||
'''Ecthyma gangrenosum''' is an infection of the [[skin]] typically caused by ''[[Pseudomonas aeruginosa]]''. It is often seen in immunocompromised patients such as those with [[neutropenia]]. Ecthyma gangrenosum presents as a round or oval [[lesion]], 1 | '''Ecthyma gangrenosum''' is an [[infection]] of the [[skin]] typically caused by ''[[Pseudomonas aeruginosa]]''. It is often seen in [[immunocompromised]] patients such as those with [[neutropenia]]. Ecthyma gangrenosum presents as a round or oval [[lesion]], 1 to 15cm in diameter, with a halo of [[erythema]]. A [[necrotic]] center is usually present with a surrounding [[erythematous]] edge, representing where the organism invaded [[blood vessel]]s and caused [[infarction]]s. These ulcerous lesions are single or multiple and heal with [[scar]] formation, although sepsis resulting from other gram negative bacteria can also cause this condition. | ||
== Pathophysiology == | == Pathophysiology == | ||
The lesion is caused by perivascular invasion of bacteria in the dermis and subcutaneous tissue. The mechanism of tissue destruction is Pseudomonas exotoxin A, a toxin similar to [[Corynebacterium diphtheriae]] toxin that causes inactivation of [[elongation factor 2]] thus inhibition of protein synthesis, elastase, an enzyme which degrades elastin in blood vessels wall, [[phospholipase C]], which degrades phospholipids in cell membranes and pyocyanin which generates reactive oxygen species. | The lesion is caused by perivascular invasion of bacteria in the dermis and subcutaneous tissue. The mechanism of tissue destruction is Pseudomonas exotoxin A, a toxin similar to [[Corynebacterium diphtheriae]] toxin that causes inactivation of [[elongation factor 2]] thus inhibition of protein synthesis, elastase, an enzyme which degrades elastin in blood vessels wall, [[phospholipase C]], which degrades phospholipids in cell membranes and pyocyanin which generates reactive oxygen species. | ||
==Diagnosis== | |||
===Physical Examination=== | |||
====Skin==== | |||
=====Extremities===== | |||
<gallery> | |||
Image:Ecthyma gangrenosum01.jpg|Ecthyma gangrenosum. <SMALL><SMALL>''[http://www.atlasdermatologico.com.br/ Adapted from Dermatology Atlas.]''<ref name="Dermatology Atlas">{{Cite web | title = Dermatology Atlas | url = http://www.atlasdermatologico.com.br/}}</ref></SMALL></SMALL> | |||
Image:Ecthyma gangrenosum02.jpg|Ecthyma gangrenosum. <SMALL><SMALL>''[http://www.atlasdermatologico.com.br/ Adapted from Dermatology Atlas.]''<ref name="Dermatology Atlas">{{Cite web | title = Dermatology Atlas | url = http://www.atlasdermatologico.com.br/}}</ref></SMALL></SMALL> | |||
</gallery> | |||
==References== | |||
{{reflist|2}} | |||
Latest revision as of 17:38, 26 August 2014
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1];Associate Editor(s)-in-Chief: Kiran Singh, M.D. [2]
Overview
Ecthyma gangrenosum is an infection of the skin typically caused by Pseudomonas aeruginosa. It is often seen in immunocompromised patients such as those with neutropenia. Ecthyma gangrenosum presents as a round or oval lesion, 1 to 15cm in diameter, with a halo of erythema. A necrotic center is usually present with a surrounding erythematous edge, representing where the organism invaded blood vessels and caused infarctions. These ulcerous lesions are single or multiple and heal with scar formation, although sepsis resulting from other gram negative bacteria can also cause this condition.
Pathophysiology
The lesion is caused by perivascular invasion of bacteria in the dermis and subcutaneous tissue. The mechanism of tissue destruction is Pseudomonas exotoxin A, a toxin similar to Corynebacterium diphtheriae toxin that causes inactivation of elongation factor 2 thus inhibition of protein synthesis, elastase, an enzyme which degrades elastin in blood vessels wall, phospholipase C, which degrades phospholipids in cell membranes and pyocyanin which generates reactive oxygen species.
Diagnosis
Physical Examination
Skin
Extremities
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![Ecthyma gangrenosum. Adapted from Dermatology Atlas.[1]](/images/1/16/Ecthyma_gangrenosum01.jpg)
Ecthyma gangrenosum. Adapted from Dermatology Atlas.[1]
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![Ecthyma gangrenosum. Adapted from Dermatology Atlas.[1]](/images/9/99/Ecthyma_gangrenosum02.jpg)
Ecthyma gangrenosum. Adapted from Dermatology Atlas.[1]
![Ecthyma gangrenosum. Adapted from Dermatology Atlas.[1]](/index.php/File:Ecthyma_gangrenosum01.jpg)
![Ecthyma gangrenosum. Adapted from Dermatology Atlas.[1]](/index.php/File:Ecthyma_gangrenosum02.jpg)