Background: Scleroderma-associated digital ulcers (SSc-DUs) are seen in up to 50% of patients with scleroderma (SSc) and may precede complications including osteomyelitis and gangrene. The current literature regarding the risk factors for gangrene in SSc is scarce, as the presentation is becoming increasingly rare. Risk factors for gangrene in unselected patients with SSc include previous digital ulcers (DUs), previous digital gangrene, and the diffuse-cutaneous subtype of SSc (dcSSc)3, which affects the visceral organs and the skin to a higher degree than the limited-cutaneous subtype of SSc (lcSSc). Traditional cardiovascular risk factors for peripheral arterial disease (PAD) (smoking, hypertension, dyslipidemia, diabetes mellitus, previous acute cardiovascular events) have not been consistently associated with gangrene in SSc.

Case Presentation: An 81-year-old female with Raynaud’s phenomenon, sick sinus syndrome status post pacemaker implantation, and well-controlled non-insulin-dependent diabetes mellitus presented to the emergency department complaining of two weeks of left foot pain. She endorsed swelling and redness of the foot and ankle after having sustained minor trauma directly over a distal ulcer on the first digit of the affected foot. She denied prior digital ulcerations as well as a history of smoking, alcohol, and drug use. Laboratory analysis, including a complete blood count and a complete metabolic panel were within normal limits. Notably, the erythrocyte sedimentation rate and C-reactive protein suggested acute on chronic inflammation at 106 (normal range: 0-30 mm/hr) and 7.9 (0.1-0.9 mg/dL), respectively. Serology confirmed lcSSc with a positive anti-centromere antibody. Wound cultures obtained from purulent drainage grew Pseudomonas. Magnetic resonance imaging was contraindicated, given pacemaker incompatibility. Computed tomography and arterial ultrasonography of the extremity demonstrated no significant abnormalities. She was treated with six weeks of intravenous cefepime, given concerns of osteomyelitis. Soon after starting treatment, soft tissue edema subsided, and gangrenous changes were noted across the fifth digit of the left foot. Unfortunately, treatment further included digital amputation of the gangrenous digit.

Discussion: The currently available literature suggests that the development of gangrene would not be expected in the digital ulcers of the presented patient, given the absence of prior ulcerations and classically more aggressive subtype of SSc. The lack of established risk factors for both SSc-DU-associated gangrene and PAD in this patient suggests that SSc itself may have a unique disease course in the setting of trauma. A history of trauma may be a key element in helping clinicians categorize patients to determine which patients are likely to have increased disease burden and, therefore, benefit from more complex management.

Conclusion: Due to the heterogeneity and small sample sizes in the currently available cohort studies on the topic, patients with SSc of all subtypes should be educated on the risk of complications that may follow injuries of ulcerated digits. Close follow-up and treatment after injuries may prevent digital amputation.

Patients should be educated on the risk of complications after injuries of ulcerated digits and be recommended close follow-up if these occur.