Related Experiment Video
Updated: Aug 14, 2026
Subcutaneous Infection of Methicillin Resistant Staphylococcus Aureus (MRSA)
Published on: February 9, 2011
Subcutaneous nodules caused by Pseudomonas aeruginosa without sepsis
C T Aleman1, M L Wallace, W K Blaylock
1Department of Dermatology, Medical College of Virginia, Richmond 23298-0164, USA.
Abstract:
Pseudomonas aeruginosa infection can cause a wide array of skin manifestations. While some infections are mild, as are the cases with hot tub folliculitis and toe web or nail infection, others are a result of sepsis and can be fatal without prompt treatment. The classic skin finding of P. aeruginosa sepsis is Ecthyma gangrenosum, but other signs such as papules, petechiae, and hemorrhagic bullae can also be seen. Suppurative panniculitis can also be caused by P. aeruginosa sepsis and clinically manifests as solitary or multiple subcutaneous nodules. Reports in the literature describe these nodules in the setting of clinical sepsis or with positive blood cultures. We report a case of localized subcutaneous nodules on the leg caused by P. aeruginosa in a patient without sepsis or positive blood cultures. The source of the infection was thought to be from a traumatic inoculation. This raises the possibility that P. aeruginosa can cause subcutaneous nodules from a localized infection, perhaps via lymphangitic spread without the manifestations of sepsis.
Insights
Pseudomonas aeruginosa can cause skin issues, from mild folliculitis to fatal sepsis. This case shows localized nodules from P. aeruginosa without sepsis, suggesting infection spread without systemic illness.
Area of Science:
- Dermatology
- Infectious Diseases
- Microbiology
Background:
- Pseudomonas aeruginosa is a Gram-negative bacterium known to cause various skin infections.
- Severe P. aeruginosa infections can lead to sepsis, presenting with characteristic skin findings like Ecthyma gangrenosum.
- Suppurative panniculitis, manifesting as subcutaneous nodules, is a recognized skin manifestation of P. aeruginosa sepsis.
Observation:
- This report details a unique case of localized subcutaneous nodules on a patient's leg.
- The nodules were caused by Pseudomonas aeruginosa infection.
- Crucially, the patient did not exhibit signs of sepsis or have positive blood cultures.
Findings:
- The study identified P. aeruginosa as the causative agent of localized subcutaneous nodules.
- Unlike typical presentations, the infection occurred without systemic sepsis or bacteremia.
- Traumatic inoculation is suspected as the source of this localized infection.
Implications:
- This case suggests P. aeruginosa can cause subcutaneous nodules through localized infection, potentially via lymphangitic spread.
- It expands the understanding of P. aeruginosa's cutaneous manifestations beyond sepsis-related findings.
- Clinicians should consider localized P. aeruginosa infection in the differential diagnosis of subcutaneous nodules, even in non-septic patients.
