Successful Wound Closure in a Rare Manifestation of Radiation Recall Dermatitis FollowingIntralesional Chemotherapy Utilizing Fish Skin Xenografts

Introduction: Radiation recall dermatitis (RRD) is a rare inflammatory skin reaction at previously irradiatedsites, often triggered by chemotherapy drugs. The precise mechanism remains unknown, andmost cases occur within 39 days of completing radiation with the use of systemic chemotherapy.We highlight a complex case of RRD occurring 14 months post-radiation, following anintralesional 5-FU injection, emphasizing the successful utilization of fish skin xenografts inirradiated, inflamed soft tissue. To our knowledge, this is the first report of intralesional 5-FUinduced RDD.Methods:A 67-year-old female with history of multiple squamous cell carcinomas (SCC) and Hashimoto’sthyroiditis arrived at the Los Robles Wound Care Center (LRWCC) in September 2023 with alarge ulcer with surrounding erythema and induration on her left distal pretibial leg at the site ofprevious radiation therapy.Initially diagnosed with SCC on her left leg in March 2022, she underwent radiation therapyafter declining surgery. In August 2023, she received a 5-FU injection for a new SCC on her leftupper extremity, subsequently developing a large ulcer and erythema at the previously irradiatedsite within 72 hours. This was consistent with radiation recall dermatitis.Results:The ulcer was recalcitrant to initial treatment with topical and systemic antimicrobials by herradiation oncologist. Ulcer biopsy indicated acute inflammation with tissue damage, but nomalignancy. Patient underwent excisional debridement with placement of fish skin xenograftsfollowed by negative pressure wound therapy in October 2023. After multiple applications of thefish xenograft at biweekly intervals the wound robustly granulated and healed via secondaryintention by April 2024.Discussion: This case illustrates the challenges of managing wounds with previous radiation exposurecomplicated by the inflammatory RRD reaction. Effective management requires a dynamic,multi-disciplinary approach to address both immediate symptoms and long-term wound careneeds. Omega-3 fish skin xenografts are FDA approved for treating chronic and acute wounds.The product is an acellular dermal matrix harvested from Icelandic cod with a porousmicrostructure like human skin. Characteristics of the xenograft include bacterial resistance,angiogenesis, and inflammatory cytokine mitigation. This case sheds light onto a rare subtype ofradiation-induced soft-tissue injury and the application of fish skin xenografts in successfulwound closure.References: