Local Action, Systemic Reach: A Topical Desiccating Agent in Diabetic Foot-Related Necrotizing Fasciitis—A Retrospective Cohort Study

Background: Necrotizing fasciitis complicating diabetic foot infection requires rapid source control and is associated with substantial morbidity. A topical desiccating agent (TDA) may assist debridement by dehydrating necrotic tissue and potentially disrupting biofilm, but comparative clinical evidence is limited. Methods: We conducted a retrospective, single-center cohort study of 87 patients who underwent emergency surgery for diabetic foot-related necrotizing fasciitis between July 2023 and February 2026. Nineteen patients received a single application of TDA at the index operation in addition to standard care, and 68 received standard care without TDA. Treatment allocation was non-random and occurred in routine clinical practice. The primary outcome was the Laboratory Risk Indicator for Necrotizing Fasciitis (LRINEC) score at Day 7. The primary analysis used linear regression adjusted for baseline LRINEC score and baseline septic status, with heteroskedasticity-consistent type 3 (HC3) standard errors. LRINEC was treated as a laboratory-based surrogate rather than as a validated treatment-response measure. C-reactive protein (CRP), white blood cell count, and glucose at Day 0 and Day 7 were summarized descriptively. Secondary clinical outcomes were 30-day major amputation and all-cause mortality. Results: The mean LRINEC score decreased from 8.58 to 2.95 in the TDA group and from 7.51 to 5.51 in the control group. The mean change was −5.63 in the TDA group and −2.00 in the control group, an unadjusted between-group difference of −3.63 points (95% confidence interval [CI], −4.83 to −2.43; p < 0.001). Baseline sepsis was more frequent in the TDA group than in the control group (89.5% vs. 51.5%). After adjustment for baseline LRINEC score and septic status, TDA exposure was associated with a 3.01-point lower Day-7 LRINEC score (95% CI, −4.00 to −2.02; p < 0.001). At Day 7, 18 of 19 TDA-treated patients (94.7%) and 34 of 68 controls (50.0%) had an LRINEC score below 6; this threshold analysis was exploratory. CRP, white blood cell count, and glucose decreased descriptively in both groups, with numerically larger reductions in the TDA group. No major amputations or deaths occurred within 30 days in either group. No TDA-related adverse event was documented in the retrospective clinical records. Conclusions: Adjunctive TDA use was associated with a lower Day-7 LRINEC score and a greater reduction from baseline. Because treatment was not randomized, baseline severity differed between groups, LRINEC is not a validated longitudinal treatment-response measure, and assessment of clinical outcomes was limited, the findings should be interpreted as exploratory associations and confirmed in prospective multicenter studies.