Spatial transcriptome analysis of amelanotic acral melanoma reveals distant molecular determinants compared to pigmented acral melanoma.

BACKGROUND: Amelanotic acral melanoma (AAM) is a rare type of acral melanoma associated with poor prognosis. OBJECTIVES: We aimed to investigate the transcriptomic differences between AAM and pigmented acral melanoma (PAM). METHODS: The differences in spatially resolved transcriptome profiles of 9 AAM patients with 29 regions of interest (ROIs) and 11 PAM patients with 46 ROIs were investigated using S100b and CD3 morphology markers. RESULTS: In S100b-positive tumor cell areas, we detected 11 upregulated differentially expressed genes (DEGs), including chaperone/ubiquitin-associated DEGs, and 82 downregulated DEGs, including human leukocyte antigen, in AAMs compared with PAMs. Protein-protein interaction network and pathway analyses revealed significant enrichment of dysregulated translational and nonsense-mediated decay pathways but significant decreases in antigen processing and presentation, interferon signaling, and melanin biosynthesis pathways in S100b-positive ROIs of AAMs compared with those of PAMs. In tumor-associated immune cell areas, the numbers of CD8 T cells (p = 0.044) and M1 macrophages (p = 0.014) were significantly decreased, whereas those of monocytes (p = 0.045) and endothelial cells (p = 0.04) were increased in AAMs compared with those in PAMs. CONCLUSIONS: In conclusion, these findings could widen our understanding of the biological differences between AAMs and PAMs that might result in a different clinical course.

Baseline Serum neutrophil-to-lymphocyte ratio in acral melanoma compared with nonacral melanoma and its prognostic significance.

BACKGROUND: Acral lentiginous melanoma (ALM), a cutaneous melanoma subtype, exhibits a poorer prognosis than nonacral cutaneous melanoma (NACM). The neutrophil-to-lymphocyte ratio (NLR) is emerging as a prognostic indicator across diverse cancers. OBJECTIVE: We explored the baseline NLR disparities between ALM and NACM, and the NLR's prognostic significance in patients with ALM. METHODS: We reviewed records of patients with ALM and NACM diagnosed between 1997 and 2022, analyzing medical data. RESULTS: Among 327 and 159 patients with ALM and NACM, respectively, baseline NLR varied based on distinct clinicopathologic factors between ALM and NACM. In stage 3 to 4 melanomas, the median NLR for ALM (2.18; IQR, 1.70-3.08) significantly surpassed NACM (1.74; IQR, 1.33-2.53) (P = .029). In patients with ALM, high NLR (hazard ratio, 1.64; 95% CI, 1.02-2.66; P = .043) was independently correlated with poor progression-free survival when adjusting for ulceration, Breslow thickness of ≥2 mm, and nodal invasion. LIMITATIONS: Single-center, retrospective design. CONCLUSION: Advanced-stage ALM exhibited a significantly higher baseline NLR compared with that of NACM. Evaluating baseline NLR could provide valuable prognostic insights for patients with ALM.

A rare case of secondary cutaneous lymphoplasmacytic lymphoma clinically presenting as acquired cutis laxa.

Lymphoplasmacytic lymphoma (LPL) is a rare variant of non-Hodgkin lymphoma, accounting for <1% of cases. Skin involvement in LPL is quite rare-accounting for approximately 5% of extramedullary disease-and includes a variety of clinical morphologies, such as erythematous-to-violaceous plaques, violaceous nodules or tumors, and ulceration at various anatomical sites. Herein, we report the case of a 45-year-old Korean woman who presented with generalized erythematous indurated plaques and pendulous skin growths, which were asymptomatic, with marked diffuse infiltration of lymphocytes and plasma cells in the dermis. Immunohistochemical studies revealed that the lymphoid cells expressed CD3, CD79a, and cytoplasmic IgG, but lacked CD10 and IgM. Moreover, kappa light chain restriction and monoclonal immunoglobulin heavy chain gene rearrangement were observed. Upon further workup, lymphoma involvement was reported in multiple lymph nodes, including those in the cervical and axillary regions. This case shows a unique form of cutaneous LPL clinically presenting as acquired cutis laxa, emphasizing the dermatologists' need to be vigilant for variant forms of this disease.

Morphological characteristics of facial scars: A retrospective analysis according to scar location, onset, age, and cause.

The morphology of facial scars shows a wide variation in terms of texture and colour. To date, there are no reliable predictors of aberrant scarring. We conducted a retrospective analysis to identify factors associated with specific scar features and types. Photographs and medical records of 428 patients with facial scars were retrospectively reviewed. Patients with keloids were excluded. The mean age of the patients was 45.43 ± 23.13 years with a male-to-female ratio of 1:1.36. Atrophic scars were the most common (42.8%), followed by flat scars (38.7%) and hypertrophic scars (18.5%). Scars on the forehead were more likely to be atrophic, whereas scars on the chin/jaw and around the mouth were more likely to be hypertrophic. Hypopigmentation was significantly more common in scars located on the forehead. Redness (erythema) was significantly more common in scars located on the chin/jaw. Old scars were less likely to be erythematous, and hypertrophic. Atrophic scars were more common in younger patients. Scars caused by dermatologic conditions, such as acne, were more likely to be atrophic, whereas surgical scars had the lowest risk of being atrophic or hypertrophic. In conclusion, the location, onset, and cause of facial scars were associated with specific features of scars.

Clinicopathologic Characteristics of Trauma-Related Nail Apparatus Melanoma: A Comparative Study according to the Presence of Trauma prior to Melanoma Development.

BACKGROUND: Nail apparatus melanoma (NAM) is a subtype of cutaneous melanoma occurring at nail units and belongs to the acral lentiginous melanoma subgroup. Due to its unique anatomical structure to protect the acral site, mechanical trauma may have a clinicoprognostic impact on NAM. Therefore, we investigated the clinicoprognostic and histopathological characteristics of NAM according to the presence of trauma history prior to melanoma development. METHODS: Clinicopathological and follow-up data of patients with NAM according to trauma history were obtained. RESULTS: We included 87 patients with NAM, 21.8% of whom had a previous trauma history. Trauma-related NAMs were more likely to involve the toenail (p = 0.040), include a high proportion of amelanotic melanomas (p = 0.038) as well as nail bed tumor (p = 0.013), and have a longer time interval between the onset of nail change and confirmed diagnosis (p = 0.012). Moreover, survival analysis revealed that trauma-related NAMs more frequently showed progression in general (p = 0.034) and nodal metastasis (p = 0.047) and had worse prognosis in terms of progression-free survival (p = 0.004). CONCLUSION: In conclusion, NAMs with previous trauma have unique clinicoprognostic characteristics. The specific clinicopathological features of NAMs according to trauma indicate that trauma may play a role in melanoma development.

Clinicoprognostic Study of Hydroa Vacciniforme-like Lymphoproliferative Diseases: A Systematic Review.

BACKGROUND: Limited clinicopathological and prognostic data are available on hydroa vacciniforme (HV)-like lymphoproliferative diseases (HVLPD). METHODS: This systematic review searched HVLPD reports in Medline via PubMed, Embase, Cochrane, and CINAHL databases in October 2020. RESULTS: A total of 393 patients (65 classic HV, 328 severe HV/HV-like T-cell lymphoma [HVLL]) were analyzed. Among severe HV/HVLL cases, 56.0% were Asians, whereas 3.1% were Caucasians. Facial edema, hypersensitivity to mosquito bites, the onset of skin lesion, and percentage of severe HV/HVLL differed significantly by race. Progression to systemic lymphoma was confirmed in 9.4% of HVLPD patients. Death occurred in 39.7% patients with severe HV/HVLL. Facial edema was the only risk factor associated with progression and overall survival. Mortality risk was higher in Latin Americans than in Asians and Caucasians. CD4/CD8 double-negativity was significantly associated with the worst prognosis and increased mortality. CONCLUSION: HVLPD is a heterogeneous entity with variable clinicopathological features associated with genetic predispositions.

Performance of PRAME immunohistochemistry compared with that of c-Kit, c-Myc, or cyclin D1 for the diagnosis of acral melanocytic tumors.

The diagnostic role of preferentially expressed antigen in melanoma (PRAME) immunohistochemistry has not been thoroughly evaluated for acral melanocytic tumors. The objective of this study was to evaluate the utility of this modality for the diagnosis of acral melanocytic tumors compared with other potential markers. Melanocytic tumors were classified as either acral nevi, challenging melanocytic tumors (superficial atypical melanocytic proliferation of uncertain significance (SAMPUS)-favor benign (SAMPUS-FB), SAMPUS-favor malignant (SAMPUS-FM)) or acral melanomas. A total of 106 acral melanocytic tumors including acral nevi (n = 32), SAMPUS-FB (n = 17), SAMPUS-FM (n = 20), and acral melanomas (n = 37) were included. Diagnostic power, assessed using an area under the receiver operating characteristic curve (AUC) for distinguishing acral melanomas and acral nevi, was highest for PRAME (AUC = 0.997), followed by c-Myc (AUC = 0.755), cyclin D1 (AUC = 0.652), and c-Kit (AUC = 0.573). At a PRAME expression level ≥30% as a positive test for acral melanoma, the sensitivity and specificity of this marker for discriminating acral melanoma from acral nevus were 100% and 96.9%, respectively. PRAME immunohistochemistry also discriminated SAMPUS-FM from SAMPUS-FB with a sensitivity and specificity of 90.0% and 76.5%, respectively. In conclusion, PRAME immunohistochemistry can be used effectively to distinguish between various spectra of acral melanocytic neoplasms.

Anticancer Effect of Cold Atmospheric Plasma in Syngeneic Mouse Models of Melanoma and Colon Cancer.

Cold atmospheric plasma (CAP) may have applications in treating various types of malignant tumors. This study assessed the anticancer effects of CAP using melanoma and colon cancer cell lines. CAP treatment significantly reduced the in vitro viability of melanoma and colon cancer cell lines and had a negligible effect on the viability of normal human melanocytes. Additionally, CAP and epidermal growth factor receptor (EGFR) inhibitor had an additive anticancer effect in a CAP-resistant melanoma cell line. Reactive oxygen and nitrogen species known to be generated by CAP enhanced the anticancer effects of CAP and EGFR inhibitors. The in vivo anticancer activities of CAP were evaluated by testing its effects against syngeneic tumors induced in mice by melanoma and colon cancer cells. CAP treatment reduced tumor volume and weight in both cancer models, with the extent of tumor reduction dependent on the duration and number of CAP treatments. Histologic examination also revealed the tumoricidal effects of CAP in both tumor models. In conclusion, CAP inhibits the growth of mouse melanoma and colon cancer cell lines in vitro and shows tumoricidal effects against mouse models of melanoma and colon cancer in vivo.

Clinicoprognostic implications of head and neck involvement by mycosis fungoides: A retrospective cohort study.

BACKGROUND: The clinicoprognostic implications of head and neck involvement of mycosis fungoides (MF) are poorly understood. OBJECTIVES: To evaluate the association of head and neck involvement on the clinicoprognostic features of MF. METHODS: The clinical features and survival outcomes of patients with MF in a Korean academic medical center database were retrospectively evaluated according to the presence of head and neck involvement at diagnosis. FINDINGS: Cases of MF with (group A, n = 39) and without (group B, n = 85) head and neck involvement at diagnosis were identified. Advanced-stage disease (stages IIB-IVB) was more common in group A (43.6%) than in group B (5.9%) (P < .001). MF progression, extracutaneous dissemination, and large-cell transformation more commonly occurred in group A than in group B. The 10-year overall survival rate was worse in group A (53.4%) compared with group B (81.6%) (P < .001). Head and neck involvement at diagnosis was associated with poor prognosis in early-stage MF (stages IA-IIA) and was independently associated with worse progression-free survival (hazard ratio, 24.4; 95% confidence interval, 2.2-267.6; P = .009). LIMITATIONS: A single center, retrospective design. CONCLUSION: Head and neck involvement of MF was associated with a poor prognosis.

Clinical implications of facial psoriasis in children and adolescents.

BACKGROUND/OBJECTIVES: The clinical implications of facial involvement in pediatric patients with psoriasis have not been adequately studied. The objectives of this study are to evaluate the association between facial involvement and clinical features including disease severity of psoriasis in children and adolescents. METHODS: The clinical features of patients aged below 20 years diagnosed with psoriasis were retrospectively evaluated and grouped based on the presence or absence of facial involvement at presentation. Demographic and clinical data were compared between groups. RESULTS: Of the 175 patients, 110 patients (62.9%) had facial involvement of psoriasis at presentation. The group with facial involvement was significantly younger at disease onset (p = .032) and had a higher body mass index (BMI) (p = .043) and psoriasis area and severity index (PASI) score (p <.001). The severity of pruritus was significantly higher in the facial than in the non-facial group (p = .020). Involvement of the nose was associated with the highest disease severity as assessed by the PASI score and affected body surface area. A significantly higher number of treatment modalities were used in the facial group than in the non-facial group (p = .013). The BMI (odds ratio (OR), 1.39; 95% CI (confidence interval), 1.07-1.80) and PASI score (OR, 1.45; 95% CI, 1.03-2.03) were independent factors associated with facial involvement of psoriasis. CONCLUSIONS: Facial involvement in psoriasis was associated with higher disease severity and more treatment modalities in children and adolescents.

Clinical and histopathological analysis of 141 dermatofibrosarcoma protuberans in Korea: A comparative study according to trauma.

BACKGROUND: Dermatofibrosarcoma protuberans (DFSP) is a rare fibrohistiocytic tumour of unknown pathogenesis with intermediate malignant potential. Although trauma has been hypothesized as a predisposing factor for DFSP development, clinicopathological characteristics of trauma-related DFSP have not been investigated. OBJECTIVE: This study investigated the differences between trauma-associated DFSP and trauma-unrelated DFSP. METHODS: Patients histopathologically diagnosed with DFSP from January 2000 to December 2019 at the Dermatology Department were included. Clinical, histopathological, prognostic features and trauma history were analysed. RESULTS: We recruited 141 patients with DFSP (mean age, 36.1 years; male: female, 1:1.01). Recurrence and systemic metastasis were observed in 15.6% and 2.8% of patients, respectively. Older patients were likely to develop DFSP at the trauma sites more frequently on the face and lower legs. The active-growing lesions were more frequently associated with trauma-related DFSP. Multivariable logistic regression revealed that age at diagnosis (OR: 1.031; 95% CI: 1.004-1.059; p = 0.024) and tumour growth (OR: 3.336; 95% CI: 1.162-9.578, p = 0.025) were significantly associated with trauma-related DFSPs. CONCLUSIONS: The age at diagnosis, lesion location and tumour growth were associated with DFSPs in this study. Analysis of DFSP with trauma history provides a deeper understanding of long-term trauma effects on sarcoma development.

The efficacy and safety of a fractional microneedle radiofrequency device for the treatment of axillary hyperhidrosis: clinical prospective pilot study.

We aimed to evaluate the efficacy and safety of a fractional microneedle radiofrequency device (FMRD) for the treatment of primary axillary hyperhidrosis (PAH). The FMRD adopted insulated microneedles, which could be located at a depth of up to 4.5 mm and deliver a radiofrequency current in a fractional manner. Also, the device could automatically regulate the amount of the delivered energy. Sixteen Korean patients with PAH received two FMRD treatment sessions at a 3-week interval and were followed-up until week 15. The primary outcome was Patient Satisfaction Scale (PSS) score at each visit. Hyperhidrosis Disease Severity Scale (HDSS) and Global Aesthetic Improvement Scale (GAIS) were also assessed. The area and amount of sweat produced were evaluated by specific tests. Mean PSS score significantly improved from 1.6 at week 3 to 2.5 at week 15 by 56%. More than a 50% improvement in sweating assessed by the PSS score was seen in 63% and 50% of patients at weeks 11 and 15, respectively. Mean HDSS score significantly decreased by week 3 and further decreased by week 7. Mean GAIS scores improved from the first follow-up visit at week 3 and improved again at week 7. The mean hyperhidrosis area assessed by starch-iodine test significantly decreased by 36% at week 15 compared with baseline. Mean transepidermal water loss level significantly decreased by 42% at week 15 compared with baseline. No patients experienced any serious adverse events. FMRD can be an effective and safe treatment modality for PAH.

PD-1 and PD-L1 expression in Kaposi sarcoma: A comparative study according to the pathological stage and clinical characteristics.

BACKGROUND: Kaposi sarcoma (KS) is a mesenchymal tumor with distinct histopathological features according to stage of progression. Programmed death-1 (PD-1) and its ligand PD-L1 play major roles in the immune escape strategy of tumors. OBJECTIVES: This study evaluated expression of PD-1 and PD-L1 in various stages of KS and investigated associations between their expression and clinical characteristics. METHODS: Fifty cases with histopathologically diagnosed KS were classified as early or late stage. These specimens were stained with anti-PD-1 and anti-PD-L1 antibodies. The extent of expression in the intratumoral and peritumoral areas was judged by two dermatopathologists. RESULTS: PD-1 and PD-L1 were expressed in 72.2% (13/18) and 11.1% (2/18) of early-stage cases, respectively, compared with 43.8% (14/32) and 28.1% (9/32) of late-stage cases, respectively. At the late stage, PD-1 expression was significantly higher in the peritumoral area than in the intratumoral area (P = 0.001). PD-1 expression in the intratumoral area was significantly higher at the early stage than at the late stage (P = 0.013). PD-L1 expression in the peritumoral area was significantly higher at the late stage than at the early stage (P = 0.038). CONCLUSIONS: The pattern of PD-1 and PD-L1 expression differs according to the stage of KS, but is unaffected by clinical variables.

Systemic Steroid Treatment for Imatinib-Associated Severe Skin Rash in Patients with Gastrointestinal Stromal Tumor: A Phase II Study.

BACKGROUND: To achieve optimal clinical outcomes in patients with gastrointestinal stromal tumor (GIST), it is crucial to maintain sufficient dosing of imatinib. Skin rash is a common imatinib-associated adverse event and may affect compliance. This phase II study was conducted to evaluate whether imatinib-associated severe skin rash can be managed with systemic steroids without dose reduction or interruption of imatinib. This study is registered at ClinicalTrials.gov, number NCT03440515. PATIENTS AND METHODS: Between 2014 and 2016, 29 patients with imatinib-associated severe skin rash were enrolled. Skin rash of grade 2 with grade ≥2 pruritus or of grade 3 was considered severe. Oral prednisolone was administered 30 mg/day for 3 weeks, then tapered off over 12 weeks. The primary endpoint was treatment success rate (TSR). Treatment success was defined as maintaining imatinib for more than 15 weeks after completion of the steroid administration schedule without skin rash that led to additional steroid treatment or dose reduction or interruption of imatinib. RESULTS: Of the 29 patients enrolled, 22 patients with skin rash were treated successfully (TSR, 75.8%), 2 (6.9%) were evaluated as treatment failures, and 5 (17.2%) were not evaluable. The 2-year rash-free and imatinib reduction-free interval rate was 67.2% with median follow-up of 22.0 months (range, 0.4-30.3). Recurrence of severe skin rash occurred in seven patients (24.1%). Systemic steroids were well tolerated except in one patient who experienced pneumocystis pneumonia. CONCLUSION: This study demonstrated that imatinib-associated severe skin rash can be effectively controlled by systemic steroid treatment without interruption or dose reduction of imatinib in patients with GIST. IMPLICATIONS FOR PRACTICE: Imatinib has been the standard treatment of gastrointestinal stromal tumor in both adjuvant and palliative settings. It is crucial to maintain sufficient dosing of imatinib to achieve optimal clinical outcomes. Imatinib commonly causes imatinib-associated skin rash, which may worsen drug compliance. This phase II study demonstrated that systemic steroids could help maintaining the efficacy of imatinib by preventing interruption or dose reduction of imatinib. The present study provides a new administration strategy of systemic steroids and its efficacy and safety data. Thus, this study can be a cornerstone to establish treatment guidelines for imatinib-associated skin rash.

Inflammatory features and rete ridge patterns of facial solar lentigo may guide laser treatment.

Relatively little is known about the clinicopathological characteristics of solar lentigo (SL), rendering the choice of laser treatment a clinical challenge. This study compared the clinicohistopathological characteristics of patients with SL on the face with and without conspicuous inflammation. The medical records were evaluated to determine the clinical and histopathological characteristics. Based on the degree of histopathologically observed inflammation, the patients were divided into two groups, those with inflammatory and noninflammatory SL. The demographic characteristics of patients in the inflammatory (n = 62, 62.6%) and noninflammatory groups (n = 37, 37.4%) did not differ significantly. Lesion duration was shorter, and the proportion of patients whose lesions changed within 6 months was higher in the inflammatory than in the noninflammatory group. The mean longest lesion diameter was greater in the inflammatory than in the noninflammatory group. Histopathologically, epidermis was thicker in the inflammatory than in the noninflammatory group. The grade of basal hyperpigmentation was higher in the noninflammatory group, whereas telangiectasia was more frequent in the inflammatory group. The treatment response rate was lower in the inflammatory (7/21, 33.3%) than in the noninflammatory group (8/10, 80.0%). Optimal laser treatment strategies may differ in these two groups.

A case of cutaneous extranodal natural killer/T-cell lymphoma clinically and histopathologically mimicking interface dermatitis.

Extranodal natural killer/T-cell lymphoma (ENKTL) is a rare but aggressive cancer characterised by angiocentric and angiodestructive infiltration by NK-cells, or cytotoxic T-cell types. Histopathologically, ENKTL shows a multinodular or diffuse infiltration localised to vascular structures, resulting in angiodestruction and necrosis. We present a patient with an initially suspected diagnosis of benign interface dermatitis with a differential diagnosis of mycosis fungoides that was later found to be an aggressive extranodal natural killer/T-cell lymphoma of a nasal type and with a dismal prognosis.

Cutaneous angioimmunoblastic T-cell lymphoma: Epstein-Barr virus positivity and its effects on clinicopathologic features.

BACKGROUND: Epstein-Barr virus (EBV) positivity frequently presents in patients with nodal angioimmunoblastic T-cell lymphoma (AITL). However, the presence of EBV in skin lesions and its clinicopathologic significance have not been evaluated. OBJECTIVE: To analyze the clinical and histopathologic features of cutaneous AITL and evaluate EBV positivity in skin tissue and its effects on clinicopathologic features of AITL. METHODS: Clinicopathologic variables in patients with cutaneous AITL were analyzed and compared depending on EBV in situ hybridization status in skin lesions by using patients' medical records. RESULTS: Of the 86 patients with AITL, 42 had a cutaneous presentation. In situ hybridizations positive for EBV were noted in 19 of 42 patients with cutaneous AITL. EBV positivity was more common in papular and nodular skin lesions than other cutaneous morphologies, such as nonspecific rash or purpuric patches. An EBV-positive in situ hybridization was associated with a pattern of dense, superficial and deep infiltrates of pleomorphic, large-sized, atypical lymphocytes. EBV positivity in skin lesions was an independent negative prognostic factor in patients with AITL. LIMITATIONS: Retrospective study at a single institution. CONCLUSION: EBV-positive cutaneous AITL is associated with distinctive clinicopathologic features.

Expression of lymphocyte-activating gene 3 and T-cell immunoreceptor with immunoglobulin and ITIM domains in cutaneous melanoma and their correlation with programmed cell death 1 expression in tumor-infiltrating lymphocytes.

BACKGROUND: Lymphocyte-activating gene 3 (LAG-3) and T-cell immunoreceptor with immunoglobulin and immunoreceptor tyrosine-based inhibition motif (TIGIT) domains are emerging checkpoint proteins. OBJECTIVE: We evaluated LAG-3 and TIGIT protein expression patterns, correlated these patterns with programmed cell death 1 (PD-1) protein expression, and determined their effects on clinicopathologic characteristics and biologic responses in melanoma. METHODS: Diagnostic tissue from 124 patients with melanoma were evaluated for LAG-3, TIGIT, and PD-1 expression by immunohistochemistry. Clinicopathologic features and survival were analyzed according to the expression of LAG-3, TIGIT, and PD-1. RESULTS: LAG-3 and TIGIT expression on tumor-infiltrating lymphocytes were significantly correlated with that of PD-1 and was also significantly associated with negative prognostic factors: deeper Breslow thickness, lymph node involvement, and advanced stage of disease. However, PD-1 expression was not associated with clinicopathologic variables of prognostic significance. High expression of either LAG-3 or TIGIT was associated with worse survival. Subgroup analysis on the basis of Breslow thickness showed that both LAG-3 and TIGIT have prognostic significance regardless of tumor thickness. High expression of PD-1 was not predictive of survival. LIMITATIONS: Retrospective study in a single institution and possibility of type 1 error. CONCLUSION: Expression of LAG-3 and TIGIT represents an independent unfavorable prognostic factor in cutaneous melanoma.

Anti-aging and hydration efficacy of a cross-linked hyaluronic acid microstructure patch.

This study evaluated the safety and efficacy of biodegradable microstructure patches composed of cross-linked hyaluronic acid (CLHA). A primary skin irritation test showed that the CLHA patches were not an irritant, whereas a clinical study showed that application of single CLHA patches significantly improved skin hydration at the periorbital region for 3 days and at the nasolabial fold for 6 days. Patch application also improved superficial wrinkles at the periorbital region for 3 days and at the nasolabial fold for 1 day. The absence of side effects indicated that application of these CLHA microstructure patches is both safe and convenient for moisturization and anti-wrinkle effects.