Objective:To observe the long-term effect of superficial temporal fascia flap combined with severed auricle reimplantation in emergency repair of partial auricle of complete separation.Methods:The data of patients with partial auricle of complete separation admitted to Emergency Clinic of Burn and Plastic Surgery of General Hospital of Northern Theater Command from June 2014 to August 2023 were retrospectively analyzed. All of them were repaired with a superficial temporal fascia flap combined with amputating auricle reimplantation. During the operation, the superficial temporal fascia flap was harvested, and the pedicle was preserved. Then the detached auricular cartilage was removed and used as a replantation scaffold. Then the remaining skin was thinned to create a full-thickness skin graft after cartilage detachment. Referring to the position and angle of the contralateral auricle, the cartilage scaffold was sutured and fixed at the stump of the ear cartilage. The wound was covered with a superficial temporal fascia flap and a full-thickness skin graft, and then packed and sutured. The postoperative observation indicators mainly confirm whether the surgery was successful, the healing condition of the replanted ear, and whether there were problems such as skin flap necrosis, infection, hematoma, etc. The shape, color, texture and tactile recovery of the reconstructed auricle were evaluated by long-term follow-up for more than 1 year. The Vancouver scar scale (VSS) was used to assess scarring in both donor and recipient sites (total score of 0-15 points, higher scores indicated more severe scarring). The Likert 5-level scoring method was used to evaluate the patients’ satisfaction with the surgical results (total score of 30 points, ≥27 points were very satisfied, 24-26 points were somewhat satisfied, 18-23 points were indifferent, 15-17 points were somewhat dissatisfied, ≤14 points were very dissatisfied).Results:A total of 8 patients were enrolled, including 5 males and 3 females. Their ages ranged from 26 to 65 years, with an average of 41 years. All patients had unilateral ear defects, with 3 cases in the left ear and 5 cases in the right ear. The defect areas ranged from 1.5 cm × 2.5 cm to 5.0 cm × 4.0 cm. During the surgery, the harvested superficial temporoparietal fascia flaps ranged from 4.5 cm × 6.5 cm to 15.0 cm × 10.0 cm. After surgery, both the flaps and full-thickness skin graft healed satisfactorily, with primary healing observed in both the donor and recipient sites. There were no complications such as necrosis, infection, or hematoma were observed. The follow-up period ranged from 3 to 9 years, with an average of approximately 6.3 years. Except for one case that required a defatted surgery at the second stage, the reconstructed auricles of the remaining patients were basically consistent with the healthy side, with smooth contour lines, skin color and texture close to the surrounding tissues, and improved tactile sensitivity. In the final follow-up, the VSS scores for both the donor and recipient sites were ≤3 for all patients. All patients rated the surgical outcome as very satisfied.Conclusion:For the partial auricle of complete separation that has no chance of replantation, the use of superficial temporal fascia flap and detached ear composite graft to repair is a reliable and effective surgical method. Patients have good postoperative long-term effects and high levels of satisfaction.

Objective:To observe the long-term effect of superficial temporal fascia flap combined with severed auricle reimplantation in emergency repair of partial auricle of complete separation.Methods:The data of patients with partial auricle of complete separation admitted to Emergency Clinic of Burn and Plastic Surgery of General Hospital of Northern Theater Command from June 2014 to August 2023 were retrospectively analyzed. All of them were repaired with a superficial temporal fascia flap combined with amputating auricle reimplantation. During the operation, the superficial temporal fascia flap was harvested, and the pedicle was preserved. Then the detached auricular cartilage was removed and used as a replantation scaffold. Then the remaining skin was thinned to create a full-thickness skin graft after cartilage detachment. Referring to the position and angle of the contralateral auricle, the cartilage scaffold was sutured and fixed at the stump of the ear cartilage. The wound was covered with a superficial temporal fascia flap and a full-thickness skin graft, and then packed and sutured. The postoperative observation indicators mainly confirm whether the surgery was successful, the healing condition of the replanted ear, and whether there were problems such as skin flap necrosis, infection, hematoma, etc. The shape, color, texture and tactile recovery of the reconstructed auricle were evaluated by long-term follow-up for more than 1 year. The Vancouver scar scale (VSS) was used to assess scarring in both donor and recipient sites (total score of 0-15 points, higher scores indicated more severe scarring). The Likert 5-level scoring method was used to evaluate the patients’ satisfaction with the surgical results (total score of 30 points, ≥27 points were very satisfied, 24-26 points were somewhat satisfied, 18-23 points were indifferent, 15-17 points were somewhat dissatisfied, ≤14 points were very dissatisfied).Results:A total of 8 patients were enrolled, including 5 males and 3 females. Their ages ranged from 26 to 65 years, with an average of 41 years. All patients had unilateral ear defects, with 3 cases in the left ear and 5 cases in the right ear. The defect areas ranged from 1.5 cm × 2.5 cm to 5.0 cm × 4.0 cm. During the surgery, the harvested superficial temporoparietal fascia flaps ranged from 4.5 cm × 6.5 cm to 15.0 cm × 10.0 cm. After surgery, both the flaps and full-thickness skin graft healed satisfactorily, with primary healing observed in both the donor and recipient sites. There were no complications such as necrosis, infection, or hematoma were observed. The follow-up period ranged from 3 to 9 years, with an average of approximately 6.3 years. Except for one case that required a defatted surgery at the second stage, the reconstructed auricles of the remaining patients were basically consistent with the healthy side, with smooth contour lines, skin color and texture close to the surrounding tissues, and improved tactile sensitivity. In the final follow-up, the VSS scores for both the donor and recipient sites were ≤3 for all patients. All patients rated the surgical outcome as very satisfied.Conclusion:For the partial auricle of complete separation that has no chance of replantation, the use of superficial temporal fascia flap and detached ear composite graft to repair is a reliable and effective surgical method. Patients have good postoperative long-term effects and high levels of satisfaction.

Objective:To investigate the surgical method and clinical effects of the modified proper digital artery island flap in repairing complex fingertip defects.Methods:A retrospective observational study was conducted. From January 2017 to December 2021, 15 patients (15 fingers) with complex fingertip defects, involving the pulp, nail bed, and lateral wall of the nail, who met the inclusion criteria were admitted into General Hospital of Northern Theater Command, including 11 males and 4 females, aged from 18 to 55 years. The area of the post debridement wound was from 2.5 cm×2.0 cm to 3.5 cm×3.5 cm, and all the wounds were repaired by using modified proper digital artery island flap (including 3 parts: main flap, tongue-shaped flap, and triangular flap), of which the main flap was used to cover the finger pulp defect, the tongue-shaped flap was used to cover the nail bed and the nail lateral wall defect, and the triangular flap was inserted into the edge of the finger pulp wound to cover the vessel pedicle. The range of the flap ranged from 3.0 cm×2.0 cm to 4.5 cm×3.0 cm. The wound at the donor site was repaired with full-thickness skin graft of the groin, and the donor site of the skin graft was sutured directly. After operation, the survival of the flap and skin graft as well as and the appearance of the affected finger were observed. During the follow-up, the fingertip morphology of the affected finger was observed, two-point discrimination distance of the affected finger pulp was measured, and the patients' satisfaction with the efficacy (including very satisfied, satisfied, and dissatisfied) was asked, and the affected finger function was evaluated by the total active movement (TAM) system evaluation standard recommended by American Academy for Surgery of Hand.Results:After operation, the main flaps and skin grafts in 15 patients all survived; but the incision at the edge of tongue-shaped flap in one patient healed poorly, and one patient developed venous stasis at the distal end of the tongue-shaped flap; the triangular flap at the pedicle was slightly bloated in the early postoperative period and became smooth after 2 to 3 months. Overall, two patients developed subcutaneous hematoma in their flaps. All the complications were healed by appropriate dressing change, suture removal, or compression bandaging. After operation, the appearance of the flap was full and formed a prominent fingertip shape. During the follow-up of 6 months to 5 years, the fingertips of the affected fingers were prominent and full; the two-point discrimination distance of the affected finger pulp was (8.6±1.4) mm; 8 patients were very satisfied with the efficacy, 6 patients were satisfied, and one patient was dissatisfied; the functional assessment of the affected fingers were all excellent.Conclusions:The modified proper digital artery island flap can repair complex fingertip defects involving the pulp, nail bed, and lateral wall of the nail. The operation is simple, and the shape and function of the fingertip are good after surgery.

Objective:To observe the efficacy the application of endoscope assisted temporoparietal fascia flap harvest for the second-stage operation in auricular reconstruction of Nagata’s technique for microtia.Method:In this retrospective study, the clinical data were collected from the patients who received microtia reconstruction with autologous rib cartilage at the Department of Burns and Plastic Surgery, General Hospital of Northern Theater Command from January 2015 to January 2022. According to the surgical procedure, patients were divided into endoscopic group and open surgery group. In endoscopic group, endoscope-assisted temporoparietal fascia harvest were performed for the second-stage operation in auricular reconstruction of Nagata’s technique. In open surgery group, temporoparietal fascia flaps were harvested in open surgery for the second-stage operation in auricular reconstruction of Nagata’s technique. Regular follow-up was conducted to observe the survival of the fascia flaps, complications, patient satisfaction, and surgical scars. The patient satisfaction questionnaire for auricular reconstruction was used to assess patient satisfaction, and the patient and observer scar assessment scale (POSAS) was used to evaluate scar formation in the surgical area. Data analysis was performed using SPSS 26.0 statistical software. The measurement data were expressed by Mean ± SD, and the counting data were expressed as cases (%). The T-test was used to compare the age difference, length of hospital stay, intraoperative blood loss, scar length, patient satisfaction, and POSAS scores between the two groups. Chi-square test was used to compare the gender composition and incidence of complications between the two groups. P<0.05 was considered statistically significant. Results:A total of 51 patients were included, with 26 in the endoscopic group (14 men and 12 women) and 25 in the open surgery group (12 men and 13 women). The age of the patients in the endoscopic group was (9.8±2.9) years (ranging from 7 to 17 years), while in the open surgery group was (10.3±3.8) years (ranging from 7 to 17 years). The postoperative follow-up period was (15.4±3.4) months (1 to 2 years), and all fascia flaps survived without any severe complications. There were no statistically significant differences between the two groups in terms of age difference, length of hospital stay, intraoperative blood loss, postoperative satisfaction, sex composition ratio, and postoperative complications ( P>0.05). The scar quality in the endoscopy group was superior to that in the open surgery group, and POSAS scores of endoscopic group were lower than those in the open surgery group, and the difference was statistically significant ( P<0.05). Conclusion:Endoscope assisted temporoparietal fascia flap harvest for the second-stage operation in auricular reconstruction of Nagata’s technique for microtia can minimize scarring, improve the postoperative appearance and is not statistically associated with the appearance of reconstructed auricles or complications.

Objective:To observe the efficacy the application of endoscope assisted temporoparietal fascia flap harvest for the second-stage operation in auricular reconstruction of Nagata’s technique for microtia.Method:In this retrospective study, the clinical data were collected from the patients who received microtia reconstruction with autologous rib cartilage at the Department of Burns and Plastic Surgery, General Hospital of Northern Theater Command from January 2015 to January 2022. According to the surgical procedure, patients were divided into endoscopic group and open surgery group. In endoscopic group, endoscope-assisted temporoparietal fascia harvest were performed for the second-stage operation in auricular reconstruction of Nagata’s technique. In open surgery group, temporoparietal fascia flaps were harvested in open surgery for the second-stage operation in auricular reconstruction of Nagata’s technique. Regular follow-up was conducted to observe the survival of the fascia flaps, complications, patient satisfaction, and surgical scars. The patient satisfaction questionnaire for auricular reconstruction was used to assess patient satisfaction, and the patient and observer scar assessment scale (POSAS) was used to evaluate scar formation in the surgical area. Data analysis was performed using SPSS 26.0 statistical software. The measurement data were expressed by Mean ± SD, and the counting data were expressed as cases (%). The T-test was used to compare the age difference, length of hospital stay, intraoperative blood loss, scar length, patient satisfaction, and POSAS scores between the two groups. Chi-square test was used to compare the gender composition and incidence of complications between the two groups. P<0.05 was considered statistically significant. Results:A total of 51 patients were included, with 26 in the endoscopic group (14 men and 12 women) and 25 in the open surgery group (12 men and 13 women). The age of the patients in the endoscopic group was (9.8±2.9) years (ranging from 7 to 17 years), while in the open surgery group was (10.3±3.8) years (ranging from 7 to 17 years). The postoperative follow-up period was (15.4±3.4) months (1 to 2 years), and all fascia flaps survived without any severe complications. There were no statistically significant differences between the two groups in terms of age difference, length of hospital stay, intraoperative blood loss, postoperative satisfaction, sex composition ratio, and postoperative complications ( P>0.05). The scar quality in the endoscopy group was superior to that in the open surgery group, and POSAS scores of endoscopic group were lower than those in the open surgery group, and the difference was statistically significant ( P<0.05). Conclusion:Endoscope assisted temporoparietal fascia flap harvest for the second-stage operation in auricular reconstruction of Nagata’s technique for microtia can minimize scarring, improve the postoperative appearance and is not statistically associated with the appearance of reconstructed auricles or complications.

Objective:To explore the clinical efficacy of microsurgical technique combined with cosmetic suture technique in situ replantation of total scalp avulsion.Methods:The clinical data of patients with total scalp avulsion admitted to the Department of Burn and Plastic Surgery of General Hospital of Northern Theatre Command from January 2015 to December 2020 were collected. All patients were treated by microsurgical technique combined with cosmetic suture technique. Thorough debridement was performed during the operation. Active anti-shock treatment was given to the patient with hemorrhagic shock. The vascular was explored and labeled. The vascular anastomosis was conducted by microsurgical technique. The venous anastomosis was performed in the first place. The arterial anastomosis was performed according to the patient's condition. Symptomatic treatment, such as routine anti-coagulation, was given to patients after the operation. An infection prevention strategy was performed in patients. The recovery of patients was observed.Results:A total of six patients were involved in this study. All patients were females, aged from 36 to 55 years old. Various degrees of wound contamination can be seen, and one patient with hemorrhagic shock. The superficial temporal vein, supraorbital vein and sentinel vein were anastomosed in two patients, and the superficial temporal vein and sentinel vein were anastomosed in four patients. The superficial temporal artery and supratrochlear artery were anastomosed in two patients, and the superficial temporal artery was anastomosed in four patients. All patients were followed up for 3 months to 2 years, averaging 13.71 months. More than 90% of the scalp survived in three patients, 80% in two patients, and 50% in one patient. The necrotic area survived after replantation of a split-thickness skin graft. The sensory function of surviving scalp after replantation was slightly regressed. The hair growth was normal. Only superficial linear scar left. All patients were satisfied with the efficacy.Conclusions:The application of the microsurgical technique for vascular anastomosis combined with cosmetic suture technique for repair can achieve good clinical efficacy in situ replantation of total scalp avulsion.

Objective:To explore the clinical efficacy of microsurgical technique combined with cosmetic suture technique in situ replantation of total scalp avulsion.Methods:The clinical data of patients with total scalp avulsion admitted to the Department of Burn and Plastic Surgery of General Hospital of Northern Theatre Command from January 2015 to December 2020 were collected. All patients were treated by microsurgical technique combined with cosmetic suture technique. Thorough debridement was performed during the operation. Active anti-shock treatment was given to the patient with hemorrhagic shock. The vascular was explored and labeled. The vascular anastomosis was conducted by microsurgical technique. The venous anastomosis was performed in the first place. The arterial anastomosis was performed according to the patient's condition. Symptomatic treatment, such as routine anti-coagulation, was given to patients after the operation. An infection prevention strategy was performed in patients. The recovery of patients was observed.Results:A total of six patients were involved in this study. All patients were females, aged from 36 to 55 years old. Various degrees of wound contamination can be seen, and one patient with hemorrhagic shock. The superficial temporal vein, supraorbital vein and sentinel vein were anastomosed in two patients, and the superficial temporal vein and sentinel vein were anastomosed in four patients. The superficial temporal artery and supratrochlear artery were anastomosed in two patients, and the superficial temporal artery was anastomosed in four patients. All patients were followed up for 3 months to 2 years, averaging 13.71 months. More than 90% of the scalp survived in three patients, 80% in two patients, and 50% in one patient. The necrotic area survived after replantation of a split-thickness skin graft. The sensory function of surviving scalp after replantation was slightly regressed. The hair growth was normal. Only superficial linear scar left. All patients were satisfied with the efficacy.Conclusions:The application of the microsurgical technique for vascular anastomosis combined with cosmetic suture technique for repair can achieve good clinical efficacy in situ replantation of total scalp avulsion.

Objective:To investigate the effects of oleanolic acid on the growth and migration of keloid fibroblasts.Methods:Keloid tissue samples from 9 patients in the Department of Plastic Surgery of General Hospital of Northern Theater were collected and fibroblasts were cultured in vitro. Fibroblasts were treated with different concentrations of oleanolic acid and divided into three groups: control group added 0.9% NaCl; 5 μmol/L oleanolic acid group added 5 μmol/L oleanolic acid; 10 μmol/L oleanolic acid group added 10 μmol/L oleanolic acid. MTT assay was used to detect cell proliferation; flow cytometry was used to detect cell cycle. Annexin V propidium iodide (AV-PI) staining was used to detect cell apoptosis. Transwell assay was used to detect the migration of oleanolic acid. Western blotting and real-time PCR were used to detect the expression of related proteins and mRNA activity. Each group was made in triplicate. Analysis of variance was used to compare the data among the three groups. LSD- t test was used for pairwise comparison, and P<0.05 was considered to be statistically significant. Results:MTT result showed that oleanolic acid could inhibit the proliferation of cells. After 24 hours, the proliferation of cells in 5 μmol/L oleanolic acid group and 10 μmol/L oleanolic acid group were 0.660±0.020 and 0.460±0.020, respectively, compared with 0.780±0.001 in the control group, F=114.4, P<0.001. Compared with the control group, the difference was statistically significant ( t=5.94, P<0.001, t=15.60, P<0.001); flow cytometry showed that the cell cycle G1/S phase transduction was blocked, 5 μmol/L oleanolic acid group and 10 μmol/L oleanolic acid group were significantly inhibited. The percentage of G1 phase cells in the 5 μmol/L oleanolic acid group was significantly higher than that in the control group ( t=3.14, P=0.030, t=6.38, P< 0.001). AⅤ-PI staining showed that the number of apoptotic cells in the 5 μmol/L oleanolic acid group (0.9%) and 10 μmol/L oleanolic acid group (3.4%) was significantly higher than that in the control group (0.4%), and the difference among the three groups was F=119.6, P<0.001. Transwell assay showed that the migration number of cells in 5 μmol/L oleanolic acid group (57.13 ± 2.65) and 10 μmol/L oleanolic acid group (42.15 ± 2.55) was significantly lower than that in control group (72.27± 3.32), F=101.3, P<0.001. Compared with the control group, the difference was statistically significant ( t=6.50, P<0.001, t=14.41, P<0.001). Western blotting showed that oleanolic acid could inhibit the expression of Cyclin D1, Bcl-2, Bax and MMP2. Compared with the control group, 5 μmol/L oleanolic acid t=8.70, P<0.001, t=5.00, P=0.040, t=12.41, P<0.001, t=10.46, P<0.001; compared with the control group, 10 μmol/L oleanolic acid t=31.61, P<0.001, t=23.17, P<0.001, t=12.11, P<0.001, t=44.52, P<0.001. Real-time PCR reaction showed that the mRNA activity levels of Cyclin D1, Bcl-2, Bax, MMP2 were also inhibited. Compared with the control group, 5 μmol/L oleanolic acid t=5.42, P< 0.001, t=3.11, P=0.040, t=16.11, P<0.001, t=11.71, P<0.001; compared with the control group, 10 μmol/L oleanolic acid t=51.78, P<0.001, t=30.89, P<0.001, t=10.64, P<0.001, t=17.10, P< 0.001. Conclusions:Oleanolic acid (5 μmol/L and 10 μmol/L) can inhibit the proliferation and migration of keloid fibroblasts and induce apoptosis of keloid fibroblasts after treating keloid fibroblasts for 24 hours, which can inhibit the growth of keloid and be used for the prevention and treatment of keloid.

Objective:To investigate the effects of oleanolic acid on the growth and migration of keloid fibroblasts.Methods:Keloid tissue samples from 9 patients in the Department of Plastic Surgery of General Hospital of Northern Theater were collected and fibroblasts were cultured in vitro. Fibroblasts were treated with different concentrations of oleanolic acid and divided into three groups: control group added 0.9% NaCl; 5 μmol/L oleanolic acid group added 5 μmol/L oleanolic acid; 10 μmol/L oleanolic acid group added 10 μmol/L oleanolic acid. MTT assay was used to detect cell proliferation; flow cytometry was used to detect cell cycle. Annexin V propidium iodide (AV-PI) staining was used to detect cell apoptosis. Transwell assay was used to detect the migration of oleanolic acid. Western blotting and real-time PCR were used to detect the expression of related proteins and mRNA activity. Each group was made in triplicate. Analysis of variance was used to compare the data among the three groups. LSD- t test was used for pairwise comparison, and P<0.05 was considered to be statistically significant. Results:MTT result showed that oleanolic acid could inhibit the proliferation of cells. After 24 hours, the proliferation of cells in 5 μmol/L oleanolic acid group and 10 μmol/L oleanolic acid group were 0.660±0.020 and 0.460±0.020, respectively, compared with 0.780±0.001 in the control group, F=114.4, P<0.001. Compared with the control group, the difference was statistically significant ( t=5.94, P<0.001, t=15.60, P<0.001); flow cytometry showed that the cell cycle G1/S phase transduction was blocked, 5 μmol/L oleanolic acid group and 10 μmol/L oleanolic acid group were significantly inhibited. The percentage of G1 phase cells in the 5 μmol/L oleanolic acid group was significantly higher than that in the control group ( t=3.14, P=0.030, t=6.38, P< 0.001). AⅤ-PI staining showed that the number of apoptotic cells in the 5 μmol/L oleanolic acid group (0.9%) and 10 μmol/L oleanolic acid group (3.4%) was significantly higher than that in the control group (0.4%), and the difference among the three groups was F=119.6, P<0.001. Transwell assay showed that the migration number of cells in 5 μmol/L oleanolic acid group (57.13 ± 2.65) and 10 μmol/L oleanolic acid group (42.15 ± 2.55) was significantly lower than that in control group (72.27± 3.32), F=101.3, P<0.001. Compared with the control group, the difference was statistically significant ( t=6.50, P<0.001, t=14.41, P<0.001). Western blotting showed that oleanolic acid could inhibit the expression of Cyclin D1, Bcl-2, Bax and MMP2. Compared with the control group, 5 μmol/L oleanolic acid t=8.70, P<0.001, t=5.00, P=0.040, t=12.41, P<0.001, t=10.46, P<0.001; compared with the control group, 10 μmol/L oleanolic acid t=31.61, P<0.001, t=23.17, P<0.001, t=12.11, P<0.001, t=44.52, P<0.001. Real-time PCR reaction showed that the mRNA activity levels of Cyclin D1, Bcl-2, Bax, MMP2 were also inhibited. Compared with the control group, 5 μmol/L oleanolic acid t=5.42, P< 0.001, t=3.11, P=0.040, t=16.11, P<0.001, t=11.71, P<0.001; compared with the control group, 10 μmol/L oleanolic acid t=51.78, P<0.001, t=30.89, P<0.001, t=10.64, P<0.001, t=17.10, P< 0.001. Conclusions:Oleanolic acid (5 μmol/L and 10 μmol/L) can inhibit the proliferation and migration of keloid fibroblasts and induce apoptosis of keloid fibroblasts after treating keloid fibroblasts for 24 hours, which can inhibit the growth of keloid and be used for the prevention and treatment of keloid.

Background: Nickel-induced allergic contact dermatitis (Ni-ACD) is a global health problem. More detailed knowledge on the skin uptake of haptens is required. This study aimed to investigate the penetration process and distribution of nickel in skin tissues with late phase and early phase of Ni-ACD to understand the mechanisms of metal allergy. Methods: Forty Hartley guinea pigs were divided into four groups according to the NiSO₄ sensitizing concentration and the NiSO₄ challenged concentration: the 5% NiSO₄-group, 5% to 10% (sensitization-challenge; late phase group); 10% NiSO₄-group, 10% to 10% (sensitization-challenge; early-phase group); and the positive and negative controls. Pathological biopsies were performed on each group. The depth profile of nickel element concentration in the skin of guinea pigs was detected by synchrotron radiation micro X-ray fluorescence spectroscopy (SR-μ-XRF) and micro X-ray absorption near-edge spectroscopy (μ-XANES). Results: In each section, the nickel element concentration in both the 5% NiSO₄-group and 10% NiSO₄-group was significantly higher than that in the negative control group. In the upper 300-μm section of skin for the early phase group, the nickel element concentration was significantly higher than that in the lower section of skin. In deeper sections (<200 μm) of skin, the concentration of nickel in the early phase group was approximately equal to that in the late phase group. The curve of the late phase group was flat, which means that the nickel element concentration was distributed uniformly by SR-μ-XRF. According to the XANES data for the 10% NiSO₄ metal salt solution, structural changes occurred in the skin model sample, indicating that nickel was not present in the Ni²⁺ aqueous ionic state but in the nickel-binding protein. Conclusions This study showed that the distribution of the nickel element concentration in ACD skin tissue was different between the early phase and late phase groups. The nickel element was not present in the Ni²⁺ aqueous ionic state but bound with certain proteins to form a complex in the stratum corneum in ACD model tissue.