Evaluation of out-in skin transparency using a colorimeter and food dye in patients with atopic dermatitis.

BACKGROUND: Atopic dermatitis is a disease of skin barrier dysfunction and outside stimuli can cross the skin barrier. OBJECTIVES: To examine a new method for evaluating the outside to inside skin transparency with a colorimeter and yellow dyes. METHODS: In study 1, a total of 28 volunteer subjects (24 normal and four with atopic dermatitis) participated. After provocation with yellow dye, the skin colour of all the subjects was measured using a colorimeter. The skin transparency index was calculated by the changes of the skin colour to yellow. Other variables of skin function, including transepidermal water loss (TEWL) and stratum corneum hydration, were also measured. In study 2, the skin transparency index was evaluated for a cohort of 38 patients with atopic dermatitis, 27 subjects with dry skin and 29 healthy controls. RESULTS: In study 1, the measurement of skin colour (b*) using tartrazine showed good results. There was a significant relationship between the skin transparency index with tartrazine and the atopic dermatitis score (P = 0.014). No other measurements of skin function, including the TEWL, were correlated. In study 2, the skin transparency index score obtained with tartrazine in the patients with atopic dermatitis was significantly higher than that of the controls and those with dry skin (P < 0.001 and P = 0.022, respectively). However, the TEWL in patients with atopic dermatitis was not significantly higher than that of patients with dry skin and the TEWL in subjects with dry skin was not higher than that of the controls. CONCLUSIONS: This method, which used a colorimeter and food dye, is noninvasive, safe and reliable for the evaluation of out-in skin transparency and can demonstrate the characteristic dysfunction in the skin barrier in patients with atopic dermatitis.

Allergy to tartrazine in psychotropic drugs.

BACKGROUND: High psychiatric morbidity has been reported among those who complain of food intolerance or allergy. Many cases of food allergy or intolerance to drugs are not due to allergy to the food or drugs themselves, but to the additives used for coloring, flavoring, preserving, thickening, emulsifying, or stabilizing the product. Of various coloring dyes used, tartrazine (FD & C yellow no. 5) is the color most frequently incriminated in producing allergic reactions. The exact epidemiology and pattern of allergic reactions to tartrazine in psychotropic drugs have not been frequently studied and reported. METHOD: The present study included consecutive outpatients (May 1996 to April 1998) who developed allergic reactions or intolerance to tartrazine in psychotropic drugs. Total patients exposed to tartrazine-containing drugs were also recorded. The subjects showing allergic reactions to tartrazine were then exposed to non-tartrazine-containing brands. RESULTS: Of 2210 patients exposed to tartrazine-containing drugs, 83 (3.8%) developed allergic reactions. The symptoms subsided within 24 to 48 hours of stopping the drug. None of the patients showed allergy to non-tartrazine-containing brands. History of allergy to tartrazine was present in 13.2%, and 15.7% of patients had a history of aspirin sensitivity. CONCLUSION: Tartrazine allergy should be considered in patients developing drug allergy, because it would require changing the brand rather than stopping treatment with that drug.

Asthma improved by nonsteroidal anti-inflammatory drugs.

A patient who claimed benefit from aspirin for her reversible bronchospasm was challenged orally in a placebo-controlled study with aspirin and other aspirin-like drugs. Specific airways conductance and spirometry were monitored for up to 150 minutes after oral challenge. Aspirin, mefenamic acid, and ibuprofen administration resulted in marked (45% to 80%) improvement in forced expiratory volume in 1 second (FEV1) compared to lactose placebo. Indomethacin, sodium salicylate, and tartrazine resulted in modest (15% to 25%) FEV1 improvement, while phenylbutazone produced a 25% decrease. These results are discussed here in terms of the ability of these drugs to inhibit the prostaglandin synthetase enzyme system. This case suggests that aspirin and other nonsteroidal anti-inflammatory drugs may be beneficial rather than harmful in some asthmatic patients.