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Chemical peeling involves the topical application of a wounding agent with the goal of effecting an organized regeneration of the skin. The histological and ultrastructural features of actinic- and age-related damage include structural abnormalities that disrupt normal epidermal and dermal architecture. In the present study, five patients with actinically damaged skin underwent an enhanced medium depth peel using 70% glycolic acid and 35% trichloroacetic acid. Biopsy specimens were taken before the peel, and 3 months after the peel for histological and electron microscopic examination. Clinical resolution of actinic damage corresponded with restoration of epidermal polarity. Characteristic histological and ultrastructural features of the skin after peeling include markedly decreased epidermal intracytoplasmic vacuoles, decreased elastic fibres, increased activated fibroblasts and organized parallel arrays of collagen fibrils. We conclude that electron microscopic studies after a medium depth peel of photodamaged skin reveal more profound changes than those seen histologically.

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BACKGROUND: Because patients with atopic dermatitis are less prone to type IV allergies, there has been controversy regarding the role of patch testing in these patients. OBJECTIVE: The present study was conducted to evaluate the role of patch testing in atopic individuals. METHODS: One-hundred patients with hand eczema were patch tested using the standard patch test battery (HERMAL, Kurt Herrmann, Reinbek, West Germany) and the Finn chamber units. The total immunoglobulin class E (IgE) level was determined and correlated to the results of patch testing. RESULTS: Eighty-seven patients had positive patch test reactions. Among the 87 patients, 39 (44.8%) had atopic dermatitis. The most common allergens yielding positive results were nickel sulfate, 2.5%, (58.6%); potassium dichromate, 0.25% (56.3%); carba mix, 3%, (44.82%); formaldehyde, 1% in H2O, (40.22%); neomycin sulfate, 20%, (33.3%); and balsam of Peru 25%, (17.24%) respectively. Patients with atopic dermatitis were more frequently sensitive to neomycin sulfate than nonatopics. CONCLUSION: Patients with atopic dermatitis should be patch tested when indicated because they also develop contact allergic sensitization to a significant degree. Our observations indicate that patch testing with standard allergens often adds valuable information about contact sensitivity in these patients.

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BACKGROUND: Abnormal immune mechanisms are thought to be important in the pathogenesis of lichen planus (LP). This is a study to clarify the changes that occur in T lymphocytes and T lymphocyte subsets, both in situ and in peripheral blood. METHODS: A group of 100 patients with LP were included in this study. T lymphocytes and T lymphocyte subsets were detected in lesional skin by immunoperoxidase cell surface staining using monoclonal antibodies. Peripheral T lymphocytes and T lymphocyte subsets were also detected by indirect immunofluorescence using monoclonal antibodies. A group of 10 normal healthy subjects were used as controls. RESULTS: The study of the lesional T lymphocytes and T lymphocyte subsets demonstrated that helper T cells was the predominant subset in LP lesions in most of the patients. This predominance was evident irrespective of the duration of the disease and was more evident in late than in early lesions. The percentage of both total T lymphocytes and helper T cells in peripheral blood was decreased significantly in patients compared with controls. A significant decrease in helper T cells and the helper/cytotoxic T cell ratio was detected in patients with a longer duration of the disease. CONCLUSION: Activation of helper T lymphocytes that were found to be the predominant subsets in LP lesions may be responsible for epidermotropic cellular infiltrates leading to damage and destruction of epidermal cells.

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Hepatitis C (HCV) virus is recognized as the major cause of what was previously referred to as parenterally acquired (blood-mediated) non-A, non-B hepatitis. A study involving 252 transfused and nontransfused Egyptian children was conducted from November 1990 through February 1991 to determine the prevalence of HCV and the role of blood and blood and blood product transfusions in the spread of the virus. Serum specimens were assayed by a second generation enzyme immunoassay and were considered reactive only after supplemental testing using the second generation recombinant immunoblot assay. Prevalence among 84 young study subjects with hematologic disorders was 55% (46 of 84), while no HCV antibodies were detected among the two nonhematologic pediatric populations studied: 84 hospital admissions and 84 acutely ill but otherwise healthy outpatients (seeking treatment for symptoms associated with a new condition less than three weeks old in the absence of any chronic health problem). Ninety-two percent (77 of 84) of the hematology-related cases had medical histories of multiple transfusions. Positive antibody responses (46) were significantly associated with increased duration of illness (P < 0.001) and the volume and number of transfusions (P < 0.01) when compared with negative ones (38). However, prior hospitalization and/or surgery were not related to HCV antibody status. The high prevalence of HCV antibody among multiply transfused infants and children suggests that blood and blood product supplies should be regularly screened for HCV antibody.

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