Biomedical subjects
Publications and source records attributed to R M Halder.
Vitiligo is a common skin disease; however, it still remains a difficult disease to treat. Not all patients respond to current forms of treatment. There are several new treatments, surgical and nonsurgical, and immunologic, that appear to either have higher success rates than past therapies or have potential as future developments for therapy of vitiligo.
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Explore the source record for details and available documents.
Explore the source record for details and available documents.
Skin cancer is the most common type of malignancy in the United States. Incidence within the African American population remains relatively low, but data is limited for this racial group, making accurate determination of incidence and mortality difficult. Factors implicated as causative in the pathogenesis of cutaneous malignancy in African Americans include, but are by no means limited to, sunlight, albinism, burn scars, X-rays, preexisting pigmented lesions, chronic inflammation, and chronic discoid lupus erythematosus. Anatomic distribution of lesions may be similar to that seen in whites for basal cell carcinoma but not for other skin cancers. For squamous cell carcinoma, melanoma, and cutaneous T-cell lymphoma, African Americans do not as well in terms of mortality as do whites. This difference probably is due either to the fact that African Americans have more advanced stages of disease at diagnosis than do whites or, in some cases, because the course of the disease is more aggressive in African Americans for reasons yet unknown. There is a need for heightened awareness of skin cancer in African Americans by patients and physicians. Emphasis should be on education and early diagnosis with the primary goal in mind being the reduction of incidence of and mortality due to skin cancer in African Americans. In addition, because of environmental factors, African Americans will be exposed to more solar ultraviolet radiation in the future. Strategies should be developed for public education to keep this exposure to low levels in this racial group.
BACKGROUND: Vitiligo is a common disease of unknown cause. Previous studies have shown abnormalities in natural killer (NK) cell cytotoxicity in patients when NK-sensitive erythroleukemic cell lines were used as target cells. OBJECTIVE: The purpose of this study was to use melanocytes directly as target cells to determine NK and lymphokine-activated killer (LAK) cell cytotoxicity in patients with vitiligo and to determine whether NK or LAK cells can be implicated in any destructive mechanism for melanocyte cytotoxicity in vitro in this disease. METHODS: Twenty-one patients with vitiligo were compared with a control group by studying NK cell activity (NKCA) and LAK cell activity (LAKCA) on several target cells. These included K562 cells, neonatal melanocytes, and malignant melanoma cells for NKCA and neonatal melanocytes and malignant melanoma cells for LAKCA. Cytotoxicity was measured with the standard chromium 51-release assay. RESULTS: No significant differences were found between vitiligo patients and control subjects in NKCA against K562 cells or in NKCA and LAKCA against melanocytes. CONCLUSION: NK cells and LAK cells are probably not responsible for melanocyte destruction in vitiligo.
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Vitiligo is a disease of unknown origin that causes destruction of melanocytes in the skin, mucous membranes, the eyes, and occasionally in hairbulbs and in the ears. The loss of melanocytes alters both structure and function of these organs. The goals of therapy are multifold. The primary goal is to restore melanocytes to the skin so that the epidermis has a normal morphology. Such repigmented skin regains its normal immune/inflammatory functions.
Vitiligo, a pigmentary disorder of the skin, causes the appearance of white patches which are profoundly devastating to the person afflicted with this disease. This article outlines the safe use of topical PUVA therapy in the office for treating those patients with less than 20% skin surface involvement. This treatment has a response rate of approximately 50%.
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We have determined the HLA-DR and HLA-DQ phenotypes of 24 black patients with vitiligo and compared these with phenotypes of 143 local black controls. HLA-DR4 was significantly increased in patients, 38% vs 11% for controls. HLA-DQw3 was also increased in patients, 58% vs 32% for controls and may be explained in part by linkage disequilibrium with HLA-DR4. When patients were subgrouped according to family history of autoimmune disease and compared with controls, the increase in HLA-DR4 and HLA-DQw3 segregated with a positive family history. HLA-DRw6 in patients with a negative family history of autoimmune disease (64%) was significantly greater than the 10% in patients with a positive family history. When patients were subgrouped according to age at onset of disease, HLA-DR4 was increased in those with early onset of disease (younger than 20 years) while HLA-DRw6 was greater in patients who were older at onset of disease. These findings support the hypothesis of an immunogenetic influence on the expression of vitiligo in black patients with vitiligo.
The use of 8-methoxypsoralen water soaks plus ultraviolet A was evaluated retrospectively in 11 patients with moderate to severe palmoplantar psoriasis that had been resistant to previous topical therapies. Patients received twice- or thrice-weekly 30-minute hand and/or foot soaks in 8-methoxypsoralen, 2.5 mg/L, followed by UVA irradiation. The condition of one patient cleared completely, and seven showed good improvement. The range of treatments required for maximal improvement was 14 to 43 with a mean of 28. The range of maximum UVA dosage per treatment was 3.5 to 17.5 joules/cm2, and the range of cumulative UVA required for maximal improvement was 45 to 388 joules/cm2 with a mean of 165 joules/cm2. The mean serum level of 8-methoxypsoralen 60 minutes after completion of hand and foot soaks was 2.5 +/- 0.5 ng/ml compared with 95.75 +/- 10.43 ng/ml after oral 8-methoxypsoralen, 0.5 mg/kg. In our experience this treatment has been a safe and relatively effective form of therapy for resistant palmoplantar psoriasis.
A technique of permanent dermal micropigmentation using a nonallergenic iron oxide pigment to cover recalcitrant areas of vitiligo is described. The areas included in this study were the distal digits, the lips, hands, wrists, axillae, elbows, hairline, perioral area, and lower legs. The immediate postmicropigmentation results invariably showed dramatic aesthetic improvements. There was a moderate degree of fading in the majority of cases, most of which occurred within the first six weeks. The pigment that remained usually persisted with minimal to no further fading. Short- and long-term complications, which were few, mild, and resolved fully, are discussed. No allergic reactions to the pigment or koebnerization of the vitiligo have been noted.
Skin cancer is rare in blacks compared with whites in the United States. The most common form is squamous-cell carcinoma, not basal-cell carcinoma, as it is in whites. Sunlight does not appear to be an important etiologic factor in skin cancer in blacks, as most lesions occur on covered areas. Malignant melanoma is low in frequency but commonly affects acral areas and has a poor prognosis. Mycosis fungoides and dermatofibrosarcoma protuberans appear to have a high frequency among skin cancers. Squamous-cell carcinoma, malignant melanoma, and mycosis fungoides have a relatively high mortality rate in blacks. Bowen's disease and Kaposi's sarcoma occur in blacks but are rare. As there is a high frequency of squamous-cell carcinoma of the skin in blacks, prevention and early detection should benefit the patient. Considering the difficulties encountered in applying epidemiologic methods to skin cancer on a national scale, etiologic studies should be conducted in carefully selected areas. Future investigations of skin cancer in blacks should include an examination of risk factors such as burns, trauma, and diet and familial and immunologic aspects as well.
Pseudofolliculitis barbae, although not a serious medical problem, is certainly a distressing one for the affected patient. Its pathogenesis lies in an ingrown hair arising from the curved hair and follicle common in black men and women. Improper shaving techniques cause ingrown hairs through both transfollicular and extrafollicular mechanisms. Various treatment modalities exist, but there is no cure. Treatment must be individualized, as not all regimens will work for each patient. With diligence, pseudofolliculitis barbae can in many instances be controlled. Dermatitis papillaris capillitii is related to pseudofolliculitis barbae because its pathogenesis also lies in a curved hair and follicle. The treatment differs, however. Mild to moderately severe cases can be kept under good control with intralesional injections of steroid and a topical chloramphenicol and steroid cream mixture. Scarred or keloidal lesions may require surgery.
Eighty-two children (ages 6 months to 12 years) with clinical and/or histopathologic diagnoses of vitiligo were evaluated; 35 were male and 47, female. Fifty-six were black, 25 white, and 3 classified as "other." Children were compared with control groups of children with other skin diseases and with adults with vitiligo. Children had an increased incidence of segmental vitiligo (p less than 0.01). Children had an increased incidence of autoimmune and/or endocrine disease and also of premature graying in their immediate and extended family members (p less than 0.001). Six of 33 children with vitiligo tested had positive organ-specific serum autoantibodies, which was a higher incidence than in the control group of children (p less than 0.05). Eighteen percent of children treated with topical psoralens and long-wave ultraviolet light (PUVA) therapy had an acceptable response, which was less than an adult group similarly treated. We have found childhood vitiligo to be a distinct subset of vitiligo, showing increased segmental presentation; strong autoimmune and/or endocrine disease background and high incidence of premature graying in the families of affected children; the presence of organ-specific serum autoantibodies and a poor response to topical PUVA therapy.
Primary cancer of the skin is rare in blacks. The records of 126 black patients with skin cancer were reviewed. Histopathologic findings included squamous cell carcinomas (43) basal cell carcinomas (39) malignant melanomas (8) dermatofibrosarcomas (16) Bowen's disease (6) mycosis fungoides (14) and sebaceous cell carcinoma (1).There is a higher percentage of skin cancer involving covered areas in blacks than among whites. Squamous cell carcinoma was the most common skin cancer in blacks. The distribution of basal cell carcinoma in blacks was 30 percent in this series, as compared with 80 percent in whites in the 1977 to 1978 survey. The majority of patients with squamous cell carcinoma had associated predisposing conditions and lesions on non-sun-exposed skin. Sunlight and occupational chemical exposure did not appear to be associated with skin cancer in blacks in this series.
Twenty-five patients with vitiligo and twenty-five healthy control subjects were evaluated with the use of flow cytometry to compare percentages of peripheral T lymphocytes and natural killer cells. The percentages of total T lymphocytes, helper T cells, suppressor T cells, and natural killer cells were evaluated with the use of OKT3, OKT4, OKT8, and Leu-7 monoclonal antibodies, respectively. Mean total T lymphocytes and helper T cells were markedly depressed; mean natural killer cells were markedly elevated and mean suppressor T cells were moderately elevated in patients with vitiligo in comparison with control subjects. These results indicate that cell-mediated immunity is subject to some defect in regulation in patients with vitiligo. It remains to be determined whether these abnormalities are a direct cause or a result of vitiligo. Antibody-dependent cytotoxicity, utilizing killer cells with recently reported antimelanocyte antibodies found in patients, may be responsible for pigment cell destruction in vitiligo. Helper T cells may be reduced because of low levels or faulty production of T lymphocyte-stimulating factors in patients or because of a serum factor in patients that is toxic to helper T cells. The presence or absence of autoimmune and/or endocrine disease in patients with vitiligo had no effect on lymphocyte populations. There seemed to be a trend toward lower levels of helper T cells in patients having vitiligo for the shortest amount of time. In summary, the data indicate immunologic abnormalities in patients with vitiligo.