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Featured researches published by Kyu-Won Choi.


Journal of The European Academy of Dermatology and Venereology | 2013

Endothelin-1 enhances the proliferation of normal human melanocytes in a paradoxical manner from the TNF-α-inhibited condition, but tacrolimus promotes exclusively the cellular migration without proliferation: a proposed action mechanism for combination therapy of phototherapy and topical tacrolimus in vitiligo treatment

Ki-Yeol Lee; Su-Young Jeon; Jong-Chul Hong; Kyu-Won Choi; Chae-Young Lee; Sung-Jin Choi; J. Kim; Ki-Hoon Song; Ki-Ho Kim

Background  Vitiligo is an acquired pigmentary disorder caused by the destruction of melanocytes. Two of the major theories regarding the pathogenesis of vitiligo are the autoimmune theory and autocytotoxicity theory, but, the precise pathogenetic mechanism is still not clarified.


Photodermatology, Photoimmunology and Photomedicine | 2009

A Korean experience with chronic actinic dermatitis during an 18‐year period: meteorological and photoimmunological aspects

Kyu-Won Choi; Chae-Young Lee; Yeong-Kyu Lee; Young-Hun Kim; Ki-Ho Kim

BACKGROUND AND PURPOSE The authors noted that chronic actinic dermatitis (CAD) increased in connection with increased sun exposure and believed that there may be a correlation between the two. The purpose of this study was to determine the relationship between increased sun exposure and CAD. We also applied a clinical severity scoring system to determine the correlation with various laboratory parameters. MATERIALS AND METHODS We investigated trends in sun exposure in Pusan during an 18-year period. We conducted photopatch/patch testing in 51 CAD patients. We also determined the total IgE, percentage of eosinophils, and chemokine receptor profiles in the peripheral blood and analyzed correlations between laboratory data and the clinical severity of CAD. RESULTS A close correlation was demonstrated between the number of CAD patients and increased sun exposure. Positive patch test reactions and positive photopatch reactions were observed in 35 and 41 of the 51 tested patients, respectively. The total IgE levels were higher in the severe group than in the others. CCR4 expression increased in parallel with clinical severity. CONCLUSION Korean patients may have increased susceptibility to CAD with increased sun exposure. We believe that the majority of the CAD patients tested had photoallergy and contact allergy. The clinical severity seemed to correlate well with the total IgE level and CCR4 expression.


Annals of Dermatology | 2009

Comparative Study of the Gross Interpretation of Phototesting and Objective Measurement with Using a Spectrophotometer for Patients with Psoriasis and Vitiligo Treated with Narrow-band UVB

Kyu-Won Choi; Ki-Ho Kim; Young-Hun Kim

BACKGROUND Determination of the minimal erythema dose (MED) is important for developing a phototherapy protocol and to diagnosis photosensitivity disorders. But obtaining a precise and reproducible MED is quite difficult because a phototest for erythema is based on subjective assessment. OBJECTIVE The objective of our study was to compare the gross interpretation of a phototest and the objective measurement using a spectrophotometer for determining the parameters of cutaneous narrow-band UVB (NBUVB) therapy. METHODS A total of 14 psoriasis and 10 vitiligo patients who receiving NBUVB phototherapy with skin types III and IV were selected for this study. To perform phototesting, ten sites on the skin of the back were vertically exposed to a series of 10 NBUVB doses among 14 doses between 340 and 1,400 mJ/cm(2). We interpreted the gross findings of erythema and measured the L*a*b* values with using a spectrophotometer at each phototest spot and at the control skin. Also, we evaluate the relationship between the gross presentation and the spectrophotometric analysis by delta E for the assessment of the minimal perceptible erythema (MPE) and MED. RESULTS For all the subjects, the MEDs were measured in the 490~1,000 mJ/cm(2) range. The average of the colorimetric values for the control skin were L*: 64.8, a*: 7.9 and b*: 19.8. Among them, the L* value and MED value were shown to be inversely correlated, and as the L* value was decreased, the MED was increased. For the MPE, the delta E, which was the color difference of the normal skin and the phototest area, was within the range of 1.5~3.0 in 17 of the 21 patients, and 4 patients were within the range of 1.0~1.5. For the MED, among the 21 patients, the delta E of 17 patients was within the range of 3.0~6.0, and 4 patients were within the range of 6.0~12.0. CONCLUSION A spectrophotometer enables UV erythema to be assessed objectively and quantitatively, and this can compensate for the disadvantages of subjective gross interpretation when determining the MED. Delta E is a good novel and objective indicator for determining the MPE and MED. So, a spectrophotometer is a very useful instrument for developing a phototherapy protocol for psoriasis and other dermatoses and for making the diagnosis of photosensitivity disorders.


Annals of Dermatology | 2008

A Case of Trichilemmal Carcinoma Treated with Mohs Micrographic Surgery

Young-Hun Kim; Yeong-Kyu Lee; Kyu-Won Choi; Chae-Young Lee; Ki-Ho Kim

Trichilemmal carcinoma is a cutaneous adnexal tumor originating from the outer root sheath of hair follicle, and it was first described by Headington in 1976. Clinically, it usually occurs as an asymptomatic solitary papule, nodule or mass on the face or scalp. This neoplasm is a malignant counterpart of trichilemmoma, and it has been reported in the literature as trichilemmal carcinoma, tricholemmal carcinoma, malignant trichilemmoma, and tricholemmocarcinoma. Although histologically, trichilemmal carcinoma frequently has maliganant features, it has a relatively benign clinical behavior. We think Mohs micrographic surgery is a useful treatment modality in trichilemmal carcinoma because the final skin defect is smaller than a wide excision. We report a case of primary trichilemmal carcinoma which had developed on the face, treated with Mohs micrographic surgery.


Annals of Dermatology | 2009

The Photosensitivity Localized in a Vitiliginous Lesion Was Associated with the Intramuscular Injections of Synthetic Progesterone during an In Vitro Fertilization-embryo Transfer

Kyu-Won Choi; Chae-Young Lee; Yeong-Kyu Lee; Young-Hun Kim; Ki-Ho Kim

The cutaneous diseases associated with progesterone are autoimmune progesterone dermatitis, erythema multiforme-like eruption, drug-induced progesterone dermatitis and solar urticaria. Estrogen and progesterone are widely used in oral contraceptives and hormone replacement therapies, and they are rarely known to cause a photosensitive reaction. The mechanism of contraceptive-induced photosensitivity is uncertain. Estrogen, rather than progesterone, in the combined oral contraceptive pill has been most frequently implicated in the induction of photosensitivity. A 32-year-old woman presented with an erythematous patch with an itching sensation on the centrofacial area of a residual vitiligious lesion. She had a history of being previously treated with narrow band UVB for 1 year. Her skin lesions had mostly subsided, but some lesions continued. She underwent an in vitro fertilization-embryo transfer 3 months previously, and she then took synthetic progesterone for 3 weeks starting at the 4th week of pregnancy. She was in good health with neither a family history of photosensitivity nor a personal history of any other drug ingestion or topical agent such as sunscreen in association with the beginning of her lesions. Phototesting revealed her to be markedly photosensitive in the UVB and UVA ranges. The intradermal skin reactions to progesterone combined with irradiation with UVA or UVB were positive. We report here on an unusual case of photosensitivity that was localized in a vitiliginous lesion, and this was associated with the intramuscular injections of synthetic progesterone that she had received during an in vitro fertilization-embryo transfer.


Annals of Dermatology | 2010

CD4-/CD56+/CD123+ Hematodermic Neoplasm Showing Early Liver Metastasis

Kyu-Won Choi; Ki-Yeol Lee; Yeong-Kyu Lee; Bon-Seok Ku; Hong-Seok Kim; Young-Hun Kim; Ki-Ho Kim


Journal of Clinical Dermatology | 2008

Two Cases of Acneiform Eruption Caused by Epidermal Growth Factor Receptor Inhibitors

Kyu-Won Choi; Chae-Young Lee; Yeong-Kyu Lee; Hong-Seok Kim; Ki-Ho Kim; Young-Hun Kim


Journal of Clinical Dermatology | 2008

A Case of Churg-Strauss Syndrome Associated with Small Bowel Perforation following High Dose Systemic Steroid Intravenous Injection

Yeong-Kyu Lee; Kyu-Won Choi; Chae-Young Lee; Hong-Seok Kim; Ki-Ho Kim; Young-Hun Kim


Journal of Clinical Dermatology | 2007

Treatment Outcome and Satisfaction after Micrographic Surgery Using Margin Strip Method

Young-Hun Kim; Bon-Seok Ku; Yeong-Kyu Lee; Kyu-Won Choi; Ki-Hoon Song; Ki-Ho Kim; Chae-Wook Lee


Journal of Clinical Dermatology | 2008

Primary Sjogren's Syndrome Manifested as Annular Erythema and Fever of an Unknown Origin

Kyu-Won Choi; Chae-Young Lee; Young-Hun Kim; Ki-Ho Kim

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Chae-Wook Lee

Seoul National University Hospital

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