Catheter ablation of outflow tract ventricular arrhythmia with intracardiac echocardiography assistance

As the indications for catheter-based electrophysiologic procedures become more diverse and complex, accurate assessment of the anatomy of intracardiac structure has become essential for the optimal clinical outcome. Since intracardiac echocardiography (ICE) was first introduced in 1980, it has become an integral part of various electro‑ physiologic procedures enabling accurate visualization of cardiac structures and continuous monitoring of catheter position, with integration of real-time images and electroanatomic mapping. Catheter ablation for outflow tract ventricular arrhythmias (OTVAs) has been actively performed in symptomatic patients. However, the anatomic com‑ plexity of OT serves as the biggest obstacle to obtain the optimal results. In OTVAs, ICE has played an invaluable role in precisely defining the anatomic shell of OT beyond fluoroscopy and in guiding catheter manipulation in relation to critical structures like the conduction system and coronary arteries. This review article provides detailed information on comprehensive application of ICE for catheter ablation of OTVAs.

Retrospective Observational Dose-Titration Study of Subjects with Type 2 Diabetes Mellitus with Inadequate Glycemic Control on 15 mg of Pioglitazone / 임상당뇨병

BACKGROUND: The 30 mg pioglitazone tablet was recently introduced in Korea; no study has yet compared its glucose-lowering or weight gain effects to the 15 mg tablet in Korean patients with type 2 diabetes mellitus (T2DM). METHODS: The electronic medical records of 45 patients with T2DM with glycated hemoglobin (HbA1c) levels > 7.0%, despite taking 15 mg/day pioglitazone and a stable dose of other diabetes drugs for 3 months, were retrospectively reviewed. RESULTS: After dose up-titration, HbA1c levels decreased at 3- and 6-month follow-ups compared with baseline (8.5% at baseline vs. 8.2% at 3 months vs. 7.9% at 6 months; baseline vs. 3 months, P = 0.106; baseline vs. 6 months, P = 0.005; 3 months vs. 6 months, P = 0.096). In the subgroup analysis of 36 patients taking pioglitazone, sulfonylurea, and metformin, HbA1c levels also decreased at 3- and 6-month follow-ups compared with baseline (8.5 % vs. 8.2 % vs. 7.9%; baseline vs. 3 months, P = 0.289; baseline vs. 6 months, P = 0.014; 3 months vs. 6 months, P = 0.232). There was no significant body weight change (70.8 kg vs. 70.7 kg vs. 71.0 kg). CONCLUSION: Up-titrating from 15 mg to 30 mg of pioglitazone in patients with inadequate glycemic control (HbA1c > 9%) who were also taking sulfonylurea and metformin showed additive glucose-lowering effects without significant weight gain in Korean patients with T2DM.

Comparison between audio-only and audiovisual biofeedback for regulating patients' respiration during four-dimensional radiotherapy

PURPOSE: To compare audio-only biofeedback to conventional audiovisual biofeedback for regulating patients' respiration during four-dimensional radiotherapy, limiting damage to healthy surrounding tissues caused by organ movement. MATERIALS AND METHODS: Six healthy volunteers were assisted by audiovisual or audio-only biofeedback systems to regulate their respirations. Volunteers breathed through a mask developed for this study by following computer-generated guiding curves displayed on a screen, combined with instructional sounds. They then performed breathing following instructional sounds only. The guiding signals and the volunteers' respiratory signals were logged at 20 samples per second. RESULTS: The standard deviations between the guiding and respiratory curves for the audiovisual and audio-only biofeedback systems were 21.55% and 23.19%, respectively; the average correlation coefficients were 0.9778 and 0.9756, respectively. The regularities between audiovisual and audio-only biofeedback for six volunteers' respirations were same statistically from the paired t-test. CONCLUSION: The difference between the audiovisual and audio-only biofeedback methods was not significant. Audio-only biofeedback has many advantages, as patients do not require a mask and can quickly adapt to this method in the clinic.

Combined Primary Tumor and Extracranial Metastasis Status as Constituent Factor of Prognostic Indices for Predicting the Overall Survival in Patients with Brain Metastases

We retrospectively analyzed the prognostic factors on overall survival (OS) in patients with brain metastasis (BM) and evaluated the role of combined primary tumor and extracranial metastasis (ECM) status as a constituent factor for prognostic index. This study involved 897 patients with BMs who underwent radiotherapy between April 2003 and December 2009. Among the clinical parameters, multivariate analysis showed that age, Karnofsky performance status (KPS), combined primary tumor and ECM status, number of BMs, and treatment group were significant prognostic factors for OS (P < 0.05). To compare the discriminatory ability of 5 prognostic indices, i.e., recursive partitioning analysis (RPA), basic score for BMs (BSBM), score index for radiosurgery (SIR), graded prognostic assessment (GPA), and modified GPA including the combined primary tumor and ECM status (mGPA), the Akaike information criteria (AIC) were calculated. The mGPA showed the lowest AIC value, followed by RPA, GPA, SIR, and BSBM, in that order. It is implicated that modified score of pre-existing factors (i.e., age and KPS) and addition of the combined primary tumor and ECM status to the prognostic index can improve its discriminatory ability and the combined primary tumor and ECM status may be useful as one of constituent factors for prognostic index.

The impact of beam angle configuration of intensity-modulated radiotherapy in the hepatocellular carcinoma

PURPOSE: This treatment planning study was undertaken to evaluate the impact of beam angle configuration of intensity-modulated radiotherapy (IMRT) on the dose of the normal liver in hepatocellular carcinoma (HCC). MATERIALS AND METHODS: The computed tomography datasets of 25 patients treated with IMRT for HCC were selected. Two IMRT plans using five beams were made in each patient; beams with equidistance of 72degrees (Plan I), and beams with a 30degrees angle of separation entering the body near the tumor (Plan II). Both plans were generated using the same constraints in each patient. Conformity index (CI), homogeneity index (HI), gamma index, mean dose of the normal liver (Dmean_NL), Dmean_NL difference between the two plans, and percentage normal liver volumes receiving at least 10, 20, and 30 Gy (V10, V20, and V30) were evaluated and compared. RESULTS: Dmean_NL, V10, and V20 were significantly better for Plan II. The Dmean_NL was significantly lower for peripheral (p = 0.001) and central tumors (p = 0.034). Dmean_NL differences between the two plans increased in proportion to gross tumor volume to normal liver volume ratios (p = 0.002). CI, HI, and gamma indices were not significantly different for the two plans. CONCLUSION: The IMRT plan based on beams with narrow separations reduced the irradiated dose of the normal liver, which would allow radiation dose escalation for HCC.

A Case of Cystic Eccrine Spiradenoma on the Left Leg / 대한피부과학회지

Eccrine spiradenoma is a benign tumor that is differentiated into the direction of an eccrine gland. It is usually presents as a solitary, slowly-growing, intradermal or deeply subcutaneous nodule on the head and trunk. We report on a case of 32-year-old woman with a solitary, solid mass on the left leg that she'd had for 6 months. The mass was a 2.5x2x0.5 cm sized, round shaped, well demarcated solitary skin-colored nodule. The mass in our case was a relatively large and painful eccrine spiradenoma, and the mass showed cystic formation. The cyst was surrounded by cords of tumor cells. Hyaline materials were seen focally. There were two types of cells. Large pale nuclei existed adjacent to the cyst. Small dark nuclei existed at the periphery. To clarify the histogenesis of this tumor, immunohistochemical staining using various antibodies was also performed. We herein report on an unusual case of a large cystic eccrine spiradenoma.

The Association of Brachial-Ankle Pulse Wave Velocity with 30-Minute Post-Challenge Plasma Glucose Levels in Korean Adults with No History of Type 2 Diabetes / 당뇨병

BACKGROUND: Acute postprandial hyperglycemia is an important affector for atherosclerosis in subjects with glucose intolerance. We analyzed the relationship of brachial-ankle pulse wave velocity (baPWV) with fasting and post-challenge plasma glucose levels according to different time points during oral glucose tolerance test (OGTT). METHODS: In 663 subjects with fasting hyperglycemia, 75 g OGTT were performed to confirm the glucose tolerant status, and fasting, post-challenge 30-minute and 120-minute glucose levels were measured. Anthropometric measurements were done, and fasting lipid profiles were measured. baPWV were measured in all subjects and the relationship between fasting, 30- and 120-minute post-challenge glucose levels and baPWV were analyzed. RESULTS: Among the participants, 62.9% were prediabetes and 31.7% were diabetes. Mean baPWV value was significantly higher in subjects with diabetes compared with prediabetes group. In bivariate correlation analyses, age, blood pressure, total cholesterol, low density lipoprotein cholesterol, 30-minute and 120-minute post-challenge glucose levels showed significant positive correlation with baPWV value. In multiple regression analysis, 30-minute post-challenge glucose level was a weak but significant determinant for mean baPWV value even after adjustment for other confounding variables. CONCLUSIONS: Postprandial hyperglycemia, especially 30-minute glucose levels showed significant correlation with baPWV in subjects with fasting hyperglycemia. These results can imply the deleterious effect of acute hyperglycemic excursion on arterial stiffness in subjects with glucose intolerance.

The Results of Intraoperative Radiotherapy for Stomach Cancer / 대한방사선종양학회지

PURPOSE: We retrospectively analyzed the long-term results of radical surgery and intraoperative radiation therapy (IORT) in patients with stomach cancer. MATERIALS AND METHODS: From 1988 to 1994, 51 patients were treated with curative surgery and IORT. Postoperative external beam radiotherapy (EBRT) was administered to 30 patients, while adjuvant chemotherapy was administered to 35 patients. A dose of 15 Gy was irradiated with a 9 MeV electron beam as the IORT and a median dose of EBRT was 43.2 Gy (range, 7.2 to 45 Gy). The follow-up period ranged from 1~254 months, with a median follow-up period of 64 months. RESULTS: The median age of all the patients was 58 years (range, 30 to 71 years). The distribution of pathologic stage (American Joint Committee on Cancer [AJCC] 2002 tumor-note-metastasis [TNM]) was as follows: 13 stage I (25.5%), 10 stage II (19.6%), 25 stage III (49.0%), and 3 stage IV (5.9%). Distant metastases occurred in 11 patients (10 in the peritoneum and 1 in bone), including one patient with concurrent local recurrence (anastomosis site). The 5-year locoregional control, disease free survival and overall survival rates were 94.7%, 66.5%, and 51.7%, respectively. For the multivariate analysis, age, TNM stage, and EBRT were significant prognostic factors for overall survival, and only TNM stage for disease free survival. CONCLUSION: We could have achieved a high loco-regional control rate in patients with locally advanced stomach cancer by adding IORT to radical surgery. However, the benefit of IORT on survival remains to be elucidated.

Dose Distribution of Intensity Modulated Radiation Therapy in Prostate Cancer / 의학물리

The aim of this study was to compare the dose distribution of intensity modulated radiation therapy (IMRT) with 3 dimensional conformal radiation therapy (3DCRT) in prostate cancer. The IMRT plan and the 3DCRT plan used the 9 fields technique, respectively. In IMRT, tumor dose was a total dose of 66 Gy at 2.0 Gy per day, 5 days a week for 5 weeks. All cases were following the dose volume histogram (DVH) constraints. The maximum and minimum tumor dose constraints were 6,700 cGy and 6,500 cGy, respectively. The rectum dose constraints were <35% over 50 Gy. The bladder dose constraints were <35% over 40 Gy. The femur head dose constraints were <15% over 20 Gy. Tumor dose in the 3DCRT were 66 Gy. In IMRT, the maximum dose of PTV was 104.4% and minimum dose was 89.5% for given dose. In 3DCRT, the maximum dose of PTV was 105.3% and minimum dose was 85.5% for given dose. The rectum dose was 34.0% over 50 Gy in IMRT compared with 63.3% in 3DCRT. The bladder dose was 30.1% over 40 Gy in IMRT compared with 30.6% in 3DCRT. The right femur head dose was 9.5% over 20 Gy in IMRT compared with 17.5% in 3DCRT. The left femur head dose was 10.6% over 20 Gy in IMRT compared with 18.3% in 3 DCRT. The dose of critical organs (rectum, bladder, and femur head) in IMRT showed to reduce than dose of 3DCRT. The rectum dose over 50 Gy in IMRT was reduced 29.3% than 3DCRT. The bladder dose over 40 Gy in IMRT was similar to 3DCRT. The femur head dose over 20 Gy in IMRT was reduced about 7~8% than 3DCRT.

The Relationship of Adiponectin/Leptin Ratio with Homeostasis Model Assessment Insulin Resistance Index and Metabolic Syndrome in Apparently Healthy Korean Male Adults / 당뇨병

BACKGROUND: We investigated the relationships of adiponectin/leptin (A/L) ratio with cardiovascular risk factors, insulin resistance index, and metabolic syndrome (MS) in apparently healthy Korean male adults. METHODS: Sixty-eight male subjects were enrolled among the participants of an annual health check-up program (mean age, 55.1 years). Percent body fat (%) was measured using a bioelectric impedance analyzer. Serum leptin level was measured via radioimmunoassay, and adiponectin level was measured using an enzyme-linked immunosorbent assay. Homeostasis model assessment (HOMA)-insulin resistance (IR) index was calculated, and the presence of metabolic syndrome was assessed. RESULTS: Adiponectin, leptin, and A/L ratio showed significant correlations with percent body fat, lipid profile, and HOMA-IR. Mean leptin and HOMA-IR levels were significantly higher, while A/L ratio was significantly lower in subjects with MS. With increasing number of MS components, the mean values of leptin and HOMA-IR increased and the A/L ratio decreased. In multiple regression analysis, HOMA-IR was significantly correlated with triglyceride, fasting glucose, and A/L ratio, while A/L ratio was significantly correlated with body mass index and HOMA-IR. HOMA-IR and A/L ratio were significant predictors for each other after adjustment for other factors. CONCLUSION: A/L ratio correlated well with lipid profile, HOMA-IR, and the presence and number of MS components in Korean male subjects.

A case of atypical Werner syndrome without WRN gene mutations / 대한내과학회지

Werner syndrome is a rare autosomal recessive, hereditary disease that demonstrates progeroid features and has characteristic WRN gene mutations. Atypical Werner syndrome refers to a small subset of individuals who produce the normal WRN protein, but show some signs and symptoms that sufficiently overlap with Werner syndrome. Recently, we experienced a case of atypical Werner syndrome. A 43-year-old woman was admitted to our hospital due to being severely underweight. She had an operative history of cataracts in both eyes and had suffered from multiple skin ulcers, deafness, and vision loss. Physical examination revealed short stature, low body weight, flat feet, and a scleroderma-like skin change. Laboratory and clinical tests showed that the patient had diabetes mellitus, osteoporosis, and premature atherosclerotic features. Her clinical presentation and laboratory findings were consistent with Werner syndrome. We performed a WRN, LMNA gene sequence analysis, but no mutations were detected. The patient was diagnosed with atypical Werner syndrome.

A Case of Congenital Leukemia Cutis

Congenital leukemia is a rare disease that develops from birth to 6 weeks of life. Leukemia cutis involves cutaneous infiltration by leukemic cells and is an unusual manifestation of leukemia, and has been documented in 25~30% of patients with congenital leukemia. The authors report a case of congenital leukemia cutis. A newborn male presented with widespread firm dusky red papules and nodules on almost his entire body surface. Skin biopsy specimens confirmed the presence of leukemic infiltrations, and bone marrow cytology was consistent with acute myeloid leukemia of the FAB M5 type.

A Case of Wheat-Dependent Exercise-Induced Anaphylaxis

Foods are recognized as a common cause of urticaria; however, the role of food is considered to be more important in acute not chronic urticaria. Wheat is a basic ingredient found in many common foods. Food allergy to wheat is primarily described in children in the form of atopic dermatitis. It is rare in adults; where it is mainly reported in exercise-induced anaphylaxis. We report a case of wheat dependent exercise-induced anaphylaxis that occurred in a 54-year-old Korean woman.

Atopy Patch Tests for Atopic Dermatitis Patients according to the Concentration and Vehicle for the Cockroach Antigen / 대한피부과학회지

BACKGROUND:Recent studies have attempted to document the correlation of an atopy patch test (APT) and a skin prick test. The results have suggested a possible role of delayed allergic reaction in the development of eczematous skin lesions in patients with atopic dermatitis (AD) OBJECTIVE: The aim of this study was to evaluate the relationship of APT with skin prick test and specific IgE for cockroach antigen. And we attempted to find the optimal vehicle and concentration of APT for cockroach allergy in AD patient. METHODS: We performed APTs in 50 patients with AD with using German cockroach allergens (the extract with different concentrations and vehicles). The reactions were evaluated after 48 hours, and these were compared with the results of the skin prick test and the total and specific IgE levels. RESULTS: The AD patients who had cockroach allergy, according to a skin prick test or the specific IgE level, showed higher positive APT reactionsthan the non-allergic patients to cockroach. The APT reactions showed a significant relationship with the skin prick test and the specific IgE level (85.7%). With regard to the form of cockroach antigen, a positive APT was more frequent with using the powder form that with using the extract. Regarding the vehicle, petrolatum induced higher positive APT reactions than did distilled water. There was a close relationship between the antigen concentration in petrolatum base and a positive APT reaction. Ten and fifty percent cockroach antigen elicited positive APT reactions than did 1% cockroach antigen with using a petrolatum base. CONCLUSION: Petrolatum is an optimal vehicle for an APT for cockroach because an APT with a petrolatum base revealed the highest correlation with cockroach allergy. The dose-response relationship between antigen concentration and the frequencies of positive APT reactions demonstrated that 10% and 50% cockroach antigen is superior to 1% cockroach antigen.

Wheat-dependent, Exercise-induced Anaphylaxis: A Successful Case of Prevention with Ketotifen

Food-dependent, exercise-induced anaphylaxis (FDEIA) is the triggering of anaphylaxis after ingestion of certain foods when followed by physical exercise. Symptoms vary from the typical generalized urticaria to severe allergic reactions. We report the case of a 20-year-old woman who had a 7-year history of recurrent wheals and dyspnea after ingesting several kinds of food (wheat, pork, and beef) along with physical exercise. Based on a provocation test, she was diagnosed with wheat-dependent, exercise-induced anaphylaxis. She was instructed to take 2 mg of ketotifen 2 hours before ingestion of wheat to prevent the symptoms, and subsequently the provocation test did not elicit wheals. We therefore prescribed ketotifen (1 mg twice a day). She has not had recurrent wheals or dyspnea for 6 months. We herein report an interesting case of wheat-dependent, exercise-induced anaphylaxis with successful prevention by ketotifen.

A Case of Churg-Strauss Syndrome

Churg-Strauss syndrome (CSS) or allergic granulomatosis angiitis is a rare primary vasculitic disease. CSS can be diagnosed by the presence of any four or more of the six criteria, which include asthma, eosinophilia greater than 10%, paranasal sinusitis, pulmonary infiltration, histological proof of vasculitis and mono- or poly-neuropathy. We report here on a 45-year-old male who developed erythematous macules, papules and hemorrhagic vesicles on both right extremities along with a tingling sensation and sacral pain. He has been suffering from recurrent allergic rhinitis and bronchial asthma for 6 months. The laboratory findings showed severe eosinophilia (22.3%), hyper-IgE and positivity for p-ANCA. On the histological examination of the hemorrhagic vesicle on the right lower leg, leukocytoclsatic vasulitis and many neutrophils and eosinophils around the cutaneous vessels were observed in the dermis.

Comparison between tension-free vaginal tape (TVT) and transobturator tape (TOT) with concomitant surgery for pelvic organ prolapse / 대한산부인과학회지

OBJECTIVE: To compare tension-free vaginal tape (TVT) and transobturator tape (TOT) for surgical treatment of stress urinary incontinence (SUI) associated with pelvic organ prolapse (POP). METHODS: Two hundred seventy eight consecutive patients affected by SUI associated with POP more than stage II were included in this retrospective study. Cure rate and postoperative complications such as hemoglobin difference between preoperative and postoperative period, vaginal hematoma, bladder and bowel injury, vaginal mesh erosion, urinary retention, de novo urgency, urinary tract infection were compared. Student's t-test and chi square test were used for statistical analysis. A P-value below 0.05 was considered statistically significant. RESULTS: The number of patients underwent TVT was 145 and TOT was 133. All patients were followed up for more than 12 months. The general characteristics of patients showed no significant difference between the two groups. There was no difference between two groups in cure rate. However, hemoglobin difference (TVT, 2.91+/-0.93 g/dL; TOT, 1.53+/-0.77 g/dL; P=0.04) was higher in TVT group than TOT group and urinary retention within 1 month (TVT, 35.17%; TOT, 21.05; P=0.02), and urinary tract infection (TVT, 11.72%; TOT, 3.75%; P=0.02) more frequently appeared in TVT group than TOT group. Other postoperative complications such as vaginal hematoma (TVT, 6.89%; TOT, 6.76%; P=0.86), bowel injury (TVT, 0%; TOT, 1.5%; P=0.64), vaginal mesh erosion (TVT, 7.58%; TOT, 4.51%; P=0.47), urinary retention after 1 month (TVT, 2.76%; TOT, 3.00%; P=0.35), de novo urgency (TVT 7.58%, TOT: 6.01%, P=0.48) were not different between two groups. CONCLUSION: Both procedures appear to be equally effective in the surgical treatment of SUI associated with POP. However, TOT seems to be a more safe procedure in postoperative complications.

A Study of an Autologous Serum Skin Test and Helicobacter pylori Infection in Patients with Chronic Idiopathic Urticaria / 대한피부과학회지

BACKGROUND: Although the pathogenesis of chronic idiopathic urticaria (CIU) has not yet been fully elucidated, previous studies have identified functional histamine-releasing autoantibodies against the alphasubunit of the high affinity IgE receptor (Fcepsilon I) and Helicobacter pylori (H. pylori) infection. OBJECTIVE: To investigate a possible association of autoimmunity and H. pylori infection with chronic idiopathic urticaria. METHODS: We prospectively performed autologous serum skin tests (ASST) and urea-breath tests (UBT) on patients with CIU. We also checked clinical features. Amoxicillin and clarithromycin combined with a proton pump inhibitor was administrated as therapy for 1 week to patients that were UBT positive. We rechecked the UBT test 4 weeks later and rechecked the clinical features 6 weeks after eradication of the infection. RESULTS: A positive result to the ASST was experienced by 56 patients (39.2%) with CIU; UBT was found in 48 patients (62.5%) with CIU. There were no significant differences in clinical features between patients with positive tests and those with negative tests. After eradication, 26 of 30 (86.7%) patients that were UBT positive showed significant clinical remission of the urticaria. CONCLUSION: According to our results, ASST is not helpful for predicting the severity or clinical course of CIU, but eradication of H. pylori in patients with chronic urticaria induces clinical remission of the urticaria.

A Study of an Autologous Serum Skin Test and Helicobacter pylori Infection in Patients with Chronic Idiopathic Urticaria / 대한피부과학회지

BACKGROUND: Although the pathogenesis of chronic idiopathic urticaria (CIU) has not yet been fully elucidated, previous studies have identified functional histamine-releasing autoantibodies against the alphasubunit of the high affinity IgE receptor (Fcepsilon I) and Helicobacter pylori (H. pylori) infection. OBJECTIVE: To investigate a possible association of autoimmunity and H. pylori infection with chronic idiopathic urticaria. METHODS: We prospectively performed autologous serum skin tests (ASST) and urea-breath tests (UBT) on patients with CIU. We also checked clinical features. Amoxicillin and clarithromycin combined with a proton pump inhibitor was administrated as therapy for 1 week to patients that were UBT positive. We rechecked the UBT test 4 weeks later and rechecked the clinical features 6 weeks after eradication of the infection. RESULTS: A positive result to the ASST was experienced by 56 patients (39.2%) with CIU; UBT was found in 48 patients (62.5%) with CIU. There were no significant differences in clinical features between patients with positive tests and those with negative tests. After eradication, 26 of 30 (86.7%) patients that were UBT positive showed significant clinical remission of the urticaria. CONCLUSION: According to our results, ASST is not helpful for predicting the severity or clinical course of CIU, but eradication of H. pylori in patients with chronic urticaria induces clinical remission of the urticaria.

A Study on the Induction of Hardening Phenomenon by Repeated Application of Sodium Lauryl Sulfate / 대한피부과학회지

BACKGROUND: Chronic irritant contact dermatitis, the common occupational dermatitis of the skin, could be caused by repetitive exposure of the skin to irritants. Adaptation of the skin to repeated influence of exogenous irritants is called the hardening. The defining characteristic of hardening phenomenon has been progressively decreasing inflammatory response with prolonged exposure to an irritant. OBJECTIVE: The purpose of this study was to evaluate the induction of hardening phenomenon by the repeated application of various concentrated sodium lauryl sulfate (SLS) solutions. METHODS: Once a day a 0.1%, 0.5%, 2% solution of SLS and distilled water were applied to the volar forearm skin in 15 healthy volunteers for 10 minutes over 3 weeks. After 3 weeks interval of rest, patch tests with 1% solution of SLS were conducted on previously irritated sites for 24 hours. We measured transepidermal water loss (TEWL) and erythema index (E-index) before irritation, during 3 weeks of repeated application. 4 days after the patches test, we measured TEWL and E-index once a day. RESULTS: During 3 weeks of irritation with repeated application of 0.1%, 0.5%, 2% SLS solution, increase of TEWL was accelerated according to concentrations of SLS. In the study of 24-h patch test with 1% SLS solution on previously irritated sites after 3 weeks interval of rest, TEWL on distilled water application site was significantly higher than other sites irritated with SLS solution on D44 and D45. The TEWL values on the site irritated with higher concentration of SLS solution were lower than those with lower concentration of SLS solution. In contrast, there were no significant differences in E-index value during 3 weeks of irritation and after 24-h patch test with 1% SLS solution. CONCLUSION: Hardening could be induced by repeated irritation with SLS solution for 3 weeks. We suggest that hardening could be induced more efficiently with the higher concentration of SLS solution than the lower concentration.