Search PubMed⌕ Search

Biomedical subjects

S K Hann

Publications and source records attributed to S K Hann.

At least 19 recordsLinked to original sources
PubMed2003

Expansion of vitiligo lesions is associated with reduced epidermal CDw60 expression and increased expression of HLA-DR in perilesional skin.

BACKGROUND: Detection of CDw60 in skin is representative of ganglioside D3 expression. This ganglioside is expressed primarily by melanocytes, and is of interest as a membrane antigen targeted by immunotherapy for melanoma patients. Expression of CDw60 by keratinocytes is defined by the presence of T-helper cell (Th)1 vs. Th2 cytokines, and can serve as a sentinel molecule to characterize an ongoing skin immune response. OBJECTIVES: These immunobiological characteristics have provided the incentive to study the expression of CDw60 in the context of progressive vitiligo. METHODS: Frozen sections were obtained from control skin and from vitiligo lesions and immunostained to show CDw60. Cells were cultured, their CDw60 expression studied and ribonuclease protection assays run to detect cytokine mRNA. RESULTS: Resistance to cytokine-mediated regulation of CDw60 expression was demonstrated in vitro by melanocytes, which appeared capable of generating autocrine and paracrine regulatory molecules supporting CDw60 expression. Induction of CDw60 expression was inhibited by antibodies to interleukin (IL)-4, suggesting that this cytokine was responsible, at least in part, for melanocyte-induced CDw60 expression. Marginal skin from patients with progressive generalized vitiligo consistently showed a reduction in epidermal CDw60 expression alongside elevated human leucocyte associated antigen (HLA)-DR expression at the margin. It thus appears that inflammatory infiltrates present in marginal skin generate type 1 rather than type 2 cytokines, supportive of a cell-mediated autoimmune response. CONCLUSIONS: These results support an active role of melanocytes within the skin immune system, and associate their loss in generalized vitiligo with a cell-mediated immune response mediated by type 1 cytokines.

Adult↗
PubMed2001

Livedoid vasculitis responding to PUVA therapy.

BACKGROUND: Livedoid vasculitis is a chronic disorder manifested as recurrent, painful, reticulated, and ulcerative lesions of the legs, which result in ivory atrophic scars with peripheral telangiectasia and hyperpigmentation. Its etiology remains obscure and therapy is difficult. In this study, we evaluated the clinical efficacy of psoralen plus UVA (PUVA) therapy and its side-effects in the treatment of livedoid vasculitis. METHODS: Eight South Korean patients with livedoid vasculitis were treated with UVA and 8-methoxypsoralen (8-MOP). Systemic PUVA was started with 4 J/cm2 of UVA two or three times a week, and then the dose was increased by 0.5 or 1 J/cm2 increments at each subsequent treatment as tolerated. The effects of treatment were evaluated using photographs of before, during, and after the study. RESULTS: All patients experienced rapid cessation of new lesion formation, significant symptom relief, and complete healing of primary lesions. The mean times for each of the above were 3.6, 5.9, and 10 weeks, and the mean cumulative doses of UVA for each of the above were 55.9, 96.8, and 197.9 J/cm2, respectively. The patients tolerated PUVA therapy well without unacceptable side-effects. CONCLUSIONS: We propose that systemic PUVA using 8-MOP should be investigated further as an alternative treatment for patients with livedoid vasculitis.

Adult↗
PubMed2000

Clinical and histopathologic characteristics of trichrome vitiligo.

BACKGROUND: The term trichrome vitiligo describes lesions that have a tan zone of varying width between normal and totally depigmented skin, which exhibits an intermediate hue. However, the pathogenesis and the histopathologic characteristics of trichrome vitiligo are unknown. OBJECTIVE: Our purpose was to investigate the clinical and histopathologic characteristics and the pathogenesis of trichrome vitiligo. METHODS: Four punch biopsy specimens were taken from 21 patients with trichrome vitiligo; they were from vitiliginous skin, light brown skin, perilesional normal skin, and normal skin as far as 5 cm from the nearest vitiligo spot. The sections were stained with hematoxylin-eosin; in selected cases, we performed immunohistochemical staining with S-100 protein and CD1a. RESULTS: Trichrome vitiligo occurred most frequently on the trunk in active vitiligo vulgaris. Focal vacuolar degeneration of the basal cell layer and mild inflammatory cell infiltration of the epidermis and dermis were more prominent in light brown skin and perilesional normal skin than in vitiliginous skin and normal skin. The number of melanocytes was decreased in light brown skin compared with perilesional normal skin (P <.05) and in vitiliginous skin compared with light brown skin (P <.05); a few melanocytes were observed even in skin affected by trichrome vitiligo. The number of Langerhans cells was increased in the epidermis of light brown skin and perilesional normal skin compared with vitiliginous and normal skin (P <.05). PUVA therapy yielded excellent repigmentation. CONCLUSION: Trichrome vitiligo is a variant of active vitiligo. The changes of melanocytes, keratinocytes, and Langerhans cells may be involved in the pathogenesis of depigmentation in trichrome vitiligo.

Adult↗
PubMed2000

A case of linear scleroderma and myasthenia gravis.

We report a case of a 28-year-old woman with myasthenia gravis who developed linear scleroderma seven years later. Myasthenia gravis and scleroderma are rarely found in direct association with each other; there are only five such reported cases, all of which were systemic scleroderma patients. Although localized and systemic scleroderma are distinct entities, autoimmunity is believed to be involved in the pathogenesis of both. Myasthenia gravis and scleroderma may occur coincidentally, but an autoimmune predisposition seems to be the more likely underlying cause, as evidenced by an increased incidence of autoantibodies and autoimmune diseases.

Adult↗
PubMed2000

A clinical analysis of 11 patients with chronic actinic dermatitis in Korea.

Chronic actinic dermatitis is a rare disease worldwide and also in Korea. However there has been no clinicohistologic and photobiological analysis of chronic actinic dermatitis in Korea. We examined 11 patients who were diagnosed as chronic actinic dermatitis and the results of this study were compared with previous reports. Most patients were elderly men who had erythematous papules or lichenified plaques on sun-exposed areas such as the face, neck, and dorsum of the hands with severe itching sensation. All patients had severe sensitivity to UVB and biopsied specimens showed findings of chronic eczema. Five patients had positive photopatch test materials. The patients were treated with systemic and topical steroid, cyclosporine and antihistamine.

Adult↗
PubMed2000

The classification of segmental vitiligo on the face.

Segmental vitiligo usually has an onset early in life and spreads rapidly within the affected area. Among 1,300 patients with vitiligo, 191 patients with segmental vitiligo involving the face were evaluated. In this study, the distribution of segmental vitiligo on the face could be classified into 5 patterns which have distinctive features. This classification of facial segmental vitiligo can provide some indication of the future distribution of early lesions if they have begun to spread.

Female↗
PubMed1999

Livedo reticularis and livedoid vasculitis responding to PUVA therapy.

Livedo reticularis is a mottled blue discoloration of the skin, which occurs in a netlike pattern. Livedoid vasculitis is a chronic disorder clinically manifested by recurrent painful ulcerations of the lower extremities and is characterized by the presence of smooth or depressed ivory-white lesions surrounded by hyperpigmentation and telangiectasia. We describe two patients with livedo reticularis and livedoid vasculitis who responded to PUVA therapy and propose that systemic PUVA with methoxsalen undergo further investigation as an alternative therapy for drug-resistant patients with livedo reticularis and livedoid vasculitis.

Adult↗
PubMed1999

Nevus depigmentosus: clinical features and histopathologic characteristics in 67 patients.

BACKGROUND: Nevus depigmentosus is defined as a congenital nonprogressive hypopigmented macule or patch that is stable in its relative size and distribution throughout life. The pathogenesis and histopathologic characteristics of nevus depigmentosus is not yet fully established. OBJECTIVE: The purpose of this study was to investigate the clinical and histopathologic characteristics of nevus depigmentosus as well as its pathogenesis. METHODS: A clinical survey was done with 67 patients diagnosed as having nevus depigmentosus. Two skin biopsy specimens each were taken from 18 patients: one from the central part of the depigmented lesion and another from the border of the lesion, including perilesional normal skin. The sections were stained with hematoxylin-eosin, Fontana-Masson, and S-100 protein. Ultrastructural evaluation was also done to detect changes of the melanocytes. RESULTS: The lesions were mostly present before 3 years of age (92.5%), but some lesions also appeared later in childhood (7.5%). The back and buttocks were the most commonly affected sites, followed by the chest and the abdomen, the face, the neck, and the arms. Forty patients (59.7%) had the isolated type of nevus depigmentosus and 27 patients (40.3%) had the segmental type. Histopathologic studies showed that the staining ability of Fontana-Masson in nevus depigmentosus lesions decreased compared with perilesional normal skin. However, there were no changes in the numbers of melanocytes identified as S-100-positive cells in the basal layer. Electronmicroscopic studies revealed a great reduction in the number of melanosomes in melanocytes and some membrane-bound aggregated melanosomes were observed in keratinocytes. CONCLUSION: The results of this study support the hypothesis that nevus depigmentosus is caused by the functional defects of melanocytes and the morphologic abnormalities of melanosomes.

Biopsy↗
PubMed1999

The efficacy of low-dose oral corticosteroids in the treatment of vitiligo patients.

BACKGROUND: One of the most probable pathogeneses of vitiligo is autoimmunity. Systemic corticosteroids suppress immunity and may arrest the progression of vitiligo and lead to repigmentation. The clinical efficacy of low-dose oral corticosteroids was assessed to minimize the side-effects in actively spreading vitiligo patients. METHODS: Eighty-one patients with vitiligo were evaluated. The patients took daily doses of oral prednisolone (0.3 mg/kg body weight) initially for 2 months; the dosage was then reduced to half of the initial dose for the third month and was halved again for the fourth and final month. The effects of treatment were evaluated using photographs of before and after the study. Side-effects were assessed at the first, second, third and fourth month of treatment. RESULTS: Arrested progression of vitiligo and repigmentation were noted in 87.7% and 70.4% of patients respectively. Male sex, a patient age of 15 years or under, and a duration of disease of 2 years or less showed increased repigmentation with statistical significance. The side-effects of treatment were minimal and did not affect the course of treatment. CONCLUSIONS: Low-dose oral corticosteroids are effective without serious side-effects in preventing the progression and inducing repigmentation of actively spreading vitiligo, which is difficult to treat with topical corticosteroids or photochemotherapy.

Abdominal Pain↗
PubMed1999

Serum levels of folic acid and vitamin B12 in Korean patients with vitiligo.

The association of vitiligo and pernicious anemia has been previously documented. The low levels of folic acid and vitamin B12 were thought to be related to vitiligo. To date, there have been very few reports about the serum levels of folic acid and vitamin B12 in patients with vitiligo. Using radioimmunoassay, we measured the serum levels of folic acid and vitamin B12 in 100 Korean patients with vitiligo. The mean serum levels of folic acid and vitamin B12 were 6.31 +/- 2.82 ng/ml and 630.25 +/- 230.94 pg/ml, respectively, in patients with vitiligo. These levels showed no significant difference compared to the normal control group, suggesting that folic acid and vitamin B12 do not appear to play a role in the pathogenesis of vitiligo.

Adolescent↗
PubMed1998

Acantholytic dyskeratotic epidermal nevus induced by ultraviolet B radiation.

We report a case of acantholytic dyskeratotic epidermal nevus induced by repeated ultraviolet B radiation in a 16-year-old Korean girl. She had experienced pruritic skin rashes on the right side of the abdomen and flank area in a zosteriform distribution for the past 10 years. They were aggravated during the summer and spontaneously disappeared in the winter. Papules revealed acantholytic dyskeratotic cells that were diagnosed as acantholytic dyskeratotic epidermal nevus. Suberythemal and erythemal doses of UVB were irradiated to the lesional skin (right side of abdomen) and nonlesional skin (left side of abdomen) for 4 consecutive days. UVB-induced pruritic papules were observed on the lesional skin and a biopsy specimen of the papules also showed acantholytic dyskeratotic cells, which were compatible with acantholytic dyskeratotic epidermal nevus.

Acantholysis↗
PubMed1998

The genetics of vitiligo in Korean patients.

BACKGROUND: Vitiligo is a common disorder whose exact cause is unknown, but genetic factors are thought to be involved. We analyzed 120 Korean proband families to clarify which genetic factors are involved in the pathogenesis of vitiligo in Korean patients. METHODS: The genetics of vitiligo were analyzed in 120 Korean proband families out of 1030 vitiligo patients. Each family was analyzed through a proband afflicted with vitiligo. RESULTS: In 51 (42.5%) of 120 proband families, at least one first-degree relative of the proband had vitiligo. The incidence of those affected among 1755 relatives (first-, second-, and third-degree) was found to be 8.0+/-0.6%. There was a statistically significant departure for segregation analysis which was inconsistent with inheritance as an autosomal or X-linked locus model. On the basis of our results, the inheritance pattern of vitiligo is more likely to tend toward the model of multifactorial inheritance. The threshold trait among first-degree relatives (7.2%) appeared to tend more toward the square root of the frequency in the general population (10%) than towards those of dominant (50%) or recessive (25%) models. CONCLUSIONS: These results indicate that there are certain genetic factors involved in the etiology of vitiligo, and that vitiligo seems to have a polygenic nature.

Female↗
PubMed1997

Clinical characteristics of progressive vitiligo.

BACKGROUND: Vitiligo is an acquired hypopigmentary disorder with a progressive clinical course. Various clinical characteristics and their significance in the progression of vitiligo were evaluated. METHODS: A clinical study was carried out on 400 patients who had visited the Vitiligo Special Clinic of Severance Hospital, Yonsei University College of Medicine. Questionnaires were completed regarding progression, sex, family history, clinical type, onset age, duration of disease, Koebner's phenomenon, leukotrichia, and mucosal involvement, and the results were recorded. RESULTS: Progression of vitiligo was seen in 355 patients (88.8%); 45 patients (11.2%) did not show progression. No difference in sex, onset age, or leukotrichia was noted between the two groups; however, patients with positive family histories, nonsegmental clinical type, longer duration, Koebner's phenomenon, and mucous membrane involvement showed more progression of vitiligo. CONCLUSIONS: Clinical characteristics such as family history, clinical type, duration of disease, Koebner's phenomenon, and mucous membrane involvement, may be relevant in predicting the progression or prognosis of vitiligo.

Adolescent↗
PubMed1997

The progression of nonsegmental vitiligo: clinical analysis of 318 patients.

BACKGROUND: Vitiligo is an acquired disorder with destruction of melanocytes and is characterized by cutaneous depigmentation with a progressive clinical course. We attempted to evaluate whether there was a relationship between the initial site and ultimate progression of nonsegmental vitiligo. METHODS: Three hundred and eighteen nonsegmental vitiligo patients were examined. Questionnaires regarding age, sex, duration of disease, family history, distribution of initial lesions, progression, and clinical type were recorded from personal interviews and case notes. RESULTS: Two hundred and eighty nine (90.9%) of the 318 patients showed progression of vitiligo at the time of examination. When the initial sites were the posterior trunk, hands, or feet, there was more progression of vitiligo to other body areas. The progression pattern was usually contiguous to the initial site. When the hands were the initial site, however, vitiligo most commonly progressed to the face. CONCLUSIONS: There may be a possible relationship between the initial site and ultimate progression of nonsegmental vitiligo. The progression pattern is usually contiguous to the initial site.

Back↗
PubMed1997

Lupus panniculitis treated by a combination therapy of hydroxychloroquine and quinacrine.

Lupus erythematosus panniculitis (LEP) is an unusual clinical variant of lupus erythematosus (LE) in which the cutaneous inflammatory reaction occurs primarily in the deeper corium. The common clinical features of LEP includes asymptomatic, firm, sharply defined nodules. The histologic findings are characterized by nonspecific panniculitis composed of lymphoid cells, plasma cells, and histiocytes with varying degrees of necrobiotic changes with fibrinoid deposits. In our case, a 24-year-old male patient visited our clinic with non-tender, hard, plaque-like lesions and overlying erythema on the left zygomatic, nasal, and submandibular area. Histopathologic and direct immunofluorescent findings of the lesion were compatible with LEP. His skin lesions waxed and waned with systemic steroid or hydroxychloroquine therapy. He has responded well to a combination therapy of hydroxychloroquine and quinacrine.

Adult↗