Actinic prurigo.
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Biomedical subjects
Publications and source records attributed to Bertha Torres-Alvarez.
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BACKGROUND: Actinic prurigo (AP) is a chronic familial photodermatosis usually seen in Latin-American Mestizo and Indian populations. It frequently begins in childhood and is more prevalent in females. The pathogenesis of AP has not been clearly elucidated, but previous studies have suggested an immune-mediated condition. Many drugs have been employed to treat AP patients with variable success. OBJECTIVE: To assess the clinical efficacy of pentoxifylline (PTX) in the treatment of AP patients by measuring its effects on lesions and pruritus. METHODS: 10 patients with severe AP were included to receive PTX in a 6-month open-label uncontrolled study. RESULTS: Clinical improvement of lesions was evident in all patients. Relief in pruritus was evident after 1 month of treatment and was maintained while receiving PTX. Five patients were followed up for 2 years, 2 obtained complete remission, and 3 had an important reduction in the use of corticosteroids. CONCLUSION: PTX was useful in the treatment of our actinic prurigo patients. It may induce a complete or partial remission of lesions and allow a decrease in the use of topical corticosteroids.
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A small but significant fraction of pemphigus patients do not show an adequate response to steroid therapy. P-glycoprotein (or P-gp) is a cell membrane efflux pump that expels drugs, including glucocorticoids, from the cytosol to the extracellular medium. An increased expression and/or function of P-glycoprotein in lymphoid cells could decrease the intracellular concentration of glucocorticoids, diminishing its therapeutic effects. The aim of this work was to assess the expression and activity of P-glycoprotein in the mononuclear cells (MNC) from pemphigus patients with good and poor response to steroid therapy. We studied 20 patients with pemphigus vulgaris, eight of them classified as poor responders and 12 as good responders to steroid therapy. The expression and activity of P-glycoprotein by MNC were quantified by flow cytometry, and P-glycoprotein mRNA levels were determined by a semi-quantitative RT-PCR technique. We found that the expression of P-glycoprotein at both mRNA and protein levels was similar in pemphigus patients with good and poor response to steroid therapy. Similar results were obtained regarding P-glycoprotein activity. P-glycoprotein does not seem to be involved in the poor response to steroid treatment seen in some pemphigus patients. It is important to investigate additional mechanisms that could account for the glucocorticoid resistance seen in some pemphigus patients.
BACKGROUND: Although it is important that dermatologists and the general population know the irritation potential of products marketed for dry skin used for body cleansing, this information is not usually available. OBJECTIVE: To assess the irritative effect of different soaps and liquid cleansers recommended for sensitive skin. To study the correlation of the irritation effect of each substance with its pH and with the presence or absence of syndet in the product. METHODS: Seventeen products marketed for dry skin and 12 common soaps used by the general population were studied. Fresh soap emulsions (8%) were applied to the volar side of the right forearm of 30 individuals with sensitive skin for 5 consecutive days using aluminum chambers. The appearance of irritation (erythema, scaling and fissures) was recorded, scored, and expressed in an Irritation index (IrIn). The pH of each solution was measured. RESULTS: Products with a low IrIn were White Dove (Dove, Lever Pond's, Toronto, Ontario, Canada), Dove Baby, Cetaphil (bar) (Cetaphil, Gulderma Lab., Forth Worth, TX, USA), Dove liquid cleanser for hands, Dove pink, and Aderma (Adenma, Pierre Fabre, Dermo-Cosmetique, Boulagne, France). Most corresponded to syndet products. Among the most used brand-name soap, Camay Classic (Camay, Procter & Gamble de Mexico, México, U.F.) had the lowest IrIn. Dove Baby was the only product with a neutral pH. A significant correlation between pH and the IrIn of cleansers was found (P < 0.006). CONCLUSIONS: Most products recommended for sensitive skin have a considerable irritation effect, which is related to the pH of the product. Better regulation of advertisement specifications including the pH level and type of cleanser contained is necessary for the majority of soaps and cleansers.
BACKGROUND: In Mexico, information regardiing sunscreen protection is not widely accessible from sources other than manufacturers. OBJECTIVE: To assess the Sun Protection Factor (SPF) of 12, over the counter sunscreens for oily or acne-prone skin available in the Mexican market. SETTING: Dermatology Department. Autonomous University of San Luis Potosí, Mexico. SUBJECTS AND METHODS: Twenty healthy volunteers ofskin type III and IV were tested. Sunscreen SPFs were measured using solar simulated radiation according to FDA final monograph. RESULTS: SPFs ranged between 7.8 and 26.9. Overall SPFs determined by solar simulator showed values between 22% to 74% less than the one advertised in their labels. CONCLUSIONS: We warn about the potenital risk of SPF overestimation as many of'the sunscreens tested did not comply with their offered protection. A proper regulation is needed because sunscreens are considered cosmetic products and do not require clinical tests to verify their efficacy before marketing.
INTRODUCTION: Topical prescription unlike other dosage forms is generally considered an inaccurate procedure. The fingertip unit (FTU) is a proposed measure for dosing a topical drug. FTU is the amount of ointment obtained from a tube with a 5 mm diameter nozzle, applied from the distal skin-crease to the tip of the index finger. OBJECTIVE: Asses FTU as a reference measure for topical prescription among the Mexican population. METHODS: The length of the II hand fingertip was recorded in 324 individuals and the weight of 1 FTU and its covering surface was registered. RESULTS: Average length of index fingertip was 24 mm (IC95 26.7-27.2) in males (n=40), and 24 mm (IC95 24.3-24.8) in females (n=50). One FTU weighed 0.45 g (IC95 0.41-0.48) in males (n=40), and 0.38 g (IC95 0.35-0.41) in females (n=50). One FTU covered 275 cm2 (IC95 255-294) in males (n=15), and 257 cm2 (IC95 200-240) in females (n=15). CONCLUSION: FTU may be a helpful measure for dosing and supervising the administration of topical medications for both patients and dermatologists in Mexico.
BACKGROUND: The effects of solar radiation in human health is dependent upon environment, behavior, and genetic characteristics. OBJECTIVE: Identify phenotypic features, attitudes, knowledge and preventive measures concerning sun exposure among a local population. METHODS: People older than 15 years were interviewed concerning time of sun exposure, photoprotection, and general knowledge about adverse effects of sun irradiation. RESULTS: 964 questionnaires were analyzed. White-skin population represented 7.4%, light-brown 24.8%, dark-brown 67.8%. Exposure time on working days was up to 15 min in 27.8%, and more than 60 min in 38.8%. On weekends, time exposure was similar. 30% did not take any preventive measures 41% wore hats and 11.8% used sunscreens. Among participants, 85.4% were aware that sun exposure caused skin cancer, 64. 1% knew that mortality is increased, 83.4% reported that excessive sun exposure is related to aging of the skin, and 26.5% believed tanning is healthy. CONCLUSIONS: In spite of thefact that a great majority of the population recognized that sun exposure produces aging and skin cancer, their exposure is widespread. This survey may be a valuable tool to design preventive public health campaigns that target high risk groups.