What is the clinical presentation of Pseudomonas skin infections?

Updated: Dec 17, 2018
  • Author: Selina SP Chen, MD, MPH; Chief Editor: Russell W Steele, MD  more...
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Skin infections

  • The hallmark lesions resulting from pseudomonal wound infections are multifocal, with dark-brown to black or violaceous discoloration of the burn eschar, and are accompanied by edema and hemorrhagic necrosis.

  • EG lesions are multiple noncontiguous ulcers or solitary ulcers. These lesions begin as isolated, red, purpuric macules that become vesicular, indurated, and, eventually, bullous or pustular. The bullae may be hemorrhagic but contain little if any pus. Lesions can remain localized or, more often, can extend over several centimeters. The central area of these lesions becomes hemorrhagic and necrotic, and then the lesion denudes to form a gangrenous ulcer with a gray-black eschar and erythematous halo. Although lesions can occur anywhere, they occur mainly in the gluteal and perineal regions (57%), the extremities (30%), the trunk (6%), and the face (6%). These skin lesions slowly heal. Patients with septicemia have associated signs that include elevated temperatures, chills, hypotension, tachycardia, and tachypnea.

  • In chronic paronychia, the skin around the nail becomes pale, red, painful, and swollen. A small amount of pus may occasionally be expressed from beneath the proximal nail fold. The nail plate turns green-black, which is characteristic of pseudomonal infections. The conditions cause little discomfort or inflammation. This presentation is often confused with subungual hematoma.

  • A Pseudomonas -infected toe web presents as a thick, white, macerated scale with a green discoloration in the toe webs. The most consistent clinical feature is soggy wet toe webs and adjacent skin. In the mildest form of pseudomonal infection in the toe web, the affected tissue is damp, softened, boggy, and white. The second, third, and fourth toe webs are the most common sites of initial involvement. Severe forms may progress to denuded skin and profuse, serous, or purulent material.

  • Pseudomonal folliculitis presents with a few to more than 50 urticarial plaques that measure 0.5-3 cm in diameter, with a central papule or pustule on all skin surfaces other than the head. The rash can be a polymorphous eruption or a mixture of follicular, maculopapular, vesicular, or pustular lesions. These lesions often are pruritic; most clear in 7-10 days, leaving round spots of red-brown postinflammatory hyperpigmentation. However, some patients may have recurrent crops of lesions over an extended period of 3 months (see the image below).

    Erythematous papulopustules of pseudomonas follicu Erythematous papulopustules of pseudomonas folliculitis. Courtesy of Mark Welch, MD.
  • Pseudomonal cellulitis presents with a dusky red–to–bluish green skin discoloration and purulent discharge. The typical fruity or mouselike odor has been linked to pseudomonal infection. Vesicles and pustules may occur as satellite lesions. The eruption may spread to cover wide areas and cause systemic manifestations.

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