Alberico Motolese

Patch and prick test study of 593 healthy subjects

593 recruits selected by the Military Health Service as being healthy and without a history of present or previous dermatitis, or ocular refraction defects, were patch tested with the GIRDCA (Italian Research Group on Contact and Environmental Dermatitis) standard series, of these, 336 were also patch tested with substances used in the processing and dyeing of textiles and prick tested with 8 major allergens. 74 (12.5%) reacted to 1 or more substances. The most frequent sensitizes were: thimerosal (28 cases]. ammoniated mercury (7 cases), phenol‐formaldehyde resin (6 cases], parabens, nicked and Disperse Red 17 (4 cases Each). 113 recruits reacted to 1 or more prick test allergens. We have demonstrated the importance of establishing such reference values in healthy groups for the correct evaluation of data collected from selected groups.

Contact dermatitis and contact sensitization among enamellers and decorators in the ceramics industry

126 enamellers and 64 decorators from 5 factories underwent dermatological and allergological examination using occupational test series in order to evaluate the prevalence of dermatitis and contact sensitization and to identify the most important sensitized substances 48 workers (corresponding to 25.26”, of the study population) were sensitized with a total of 55 positive patch tests. Dermatitis was present in 22 workers, whereas 44 subjects claimed to have had skin lesions in the past. We found 17 positivities to specific substances: 7 to red iron oxide: 2 in antimony trioxide. manganese dioxide and maleic anhydride; and I lo red copper oxide, cadmium chloride, vanadium pentoxide and sodium tripolyphosphate.

Sensitization to reactive textile dyes in patients with contact dermatitis

Reactive dyes are used especially for colouring natural fibres (cotton, silk and wool) that arc widely used in Western countries, particularly Italy, in the production of clothes. The aim of our study was to investigate sensitization to the most commonly used reactive textile dyes in patients undergoing patch tests, and to assess the clinical relevance of contact sensitization of these dyes. 1813 consecutive patients underwent patch tests with the GIRDCA standard series and an additional textile series of 12 reactive dyes. 18 of these patients were sensitized to reactive dyes (0.99) (4 only to reactive dyes). The dyes most frequently responsible for positive patch tests were Red Cibacron CR and Violet Remazol 5R (respectively, 8 and 5 positivities). In 5 cases only was a history of intolerance to particular garments given; of 4 patch tests performed with pieces of garment, 2 were positive. In 1 occupationally‐exposed patient, airborne contact dermatitis was suspected. Owing to the lack of up‐to‐date patch test series, some cases of allergic contact dermatitis from textile dyes are probably misdiagnosed: new colouring agents are continuously introduced to the market, so that a close relationship with textile industry is necessary to improve our diagnostic tools.

Patch test reading: a comparison between 2 application methods

Delayed hypersensitivity to organic mercurial compounds has repeatedly been described principally to thimerosal (3) and less frequently to mercurochrome (4--6). References to immediate hypersensitivity reactions, however, are rare (1, 2, 7, 8). Association of both types of reaction in the same patient seems to be exceptional: we have found only 1 previous case report (1). Our patient presented with anaphylaxis after topical application of mercurochrome. Prick test and PK test results support a specific, lgE, mediated mechanism. We were unable to determine the clinical significance of his additional delayed hypersensitivity to mercurochrome, as has often before been the case with thimerosal (9-12). As has previously been described ( 1, 4, 5), patch tests demonstrated cross-reactivity between mercurochrome and other mercurial compounds, though the lack of cross-reaction with thimerosal, although described (4, 12), was surprising (13, 14).

Pre-treatment of nickel test areas with sodium lauryl sulfate detects nickel sensitivity in subjects reacting negatively to routinely performed patch tests.

A fair % of patients with a clinical history of nickel allergy show negative patch test results. To improve the response rate to NiSO4 5% pet, patch tests, a testing procedure utilizing pre‐treatment of I he lest area by a 24‐h application of sodium lauryl sulfate (SLS) was introduced 46 women with a clinical history of nickel sensitivity who exhibited negative reactions to nickel sulfate 5% pet, patch tests. were studied, Patients underwent d patch tests on adjacent sites on the volar surface of the forcarms. 4 patch tests were performed with a 72‐h application of 40 mg nickel sulfate 5% pet. While I of these patch tests served as control. 3 test areas underwent 24‐h pretreatment with 40 μl SLS. 1 with 0.1% and 2 with 0.5% solution. To evaluate differences in the reactivity to SLS plus nickel sulfate related to the site on the forearm, 0.5% SLS pre‐treatment was performed both on a proximal and on a distal lest site. At the 72‐h evaluation. 19 subjects out of 46 showed positive reaction to nickel sulfate 5%. At skin sites pre‐t railed with SLS. Whereas 23 patients reacted positively at 0.5% SLS pre‐treated ureas. Echographic values of skin thickness and of hypo‐echogeme dermal areas al positive pre‐treated nickel lest. Next higher than al control Jest areas, confirming the clinical evidence of an increased response to NiSO4 after SLS pre‐treatment. The inflammatory reaction, is evaluated clinically and echographically, was much higher al distal skin areas (0.l% SLS and distal (0.5%.) SLS than at proximal 0.5% SLS ones.

Contact allergy to Dermatophagoides in atopic dermatitis patients and healthy subjects

To compare different house‐dust‐mite‐derived allergenic materials and to correlate the presence of IgE LO Dermatophagoides with patch test results, 313 atopic dermatitis (AD) patients and 100 healthy volunteers (HV) underwent patch tests with: Dermatophagoides Pteronyssimus (DPT) lyophilized purified alpha fraction in buffered saline/glycerol 50% and or in petrolatum (Bayropharm); 540% DPT and 50%Dermatophagoides farinae (DF) whole bodies in petrolatum and petrolatum oil (Allergopharma‐Bracco); DPT and DF whole bodies in petrolatum and petrolatum oil (Lofarma). We found 39% positive reactions among AD subjects and 13% in HV The presence of serum‐specific IgE did not influence the patch test results. with of AD patch‐lest‐positive patients and 5 of 13 HV respectively, showed a positive prick less and or RAST lo Dermatophagoides. Similar sensitization rates were observed with the allergenic material from Bayropharm (54% positivities) and Allergopharma‐Bracco (51% positivities), whereas the preparations from Lofarma gave a 20% response rate.

Contact sensitization to preservatives in children

Case Report A 51-year-old man presented with a !-year history of eczema of the web spaces of both hands and flexural aspects of the wrists. He had worked as a chimney sweep for more than 20 years and was not aware of any changes in the materials that he handled. Patch testing to the European standard series was positive ( + +) to fragrance mix. He was also positive ( + +) to soot at 2 and 3 days, and to coal tar 5% pet. ( +) at 3 days. The patient observed that soot from smokeless fuel had a worse effect on his skin. He was patch tested to soot from both smokeless fuel and other fuel, and no differences were detected in the allergic reactions to both soots. 20 controls were tested to the soot samples with negative· results. He has been able to continue in his occupation with the help of cotton and rubber gloves.

Contact sensttization in infants: report of 3 cases

response to a piece of latex vibrator, and a piece of one brand of latex gloves (fransaflex). Scratch tests with pieces of 4 other brands of latex and vinyl gloves, and com starch, were negative. A prick test with a co=ercial extract of natural latex (Hevea brasiliensis) at 0.1% acet. (HAL) was positive. 3 control subjects were negative to the latter skin test. Specific IgE to latex (Hevea brasiliensis) (latex-k 82, Phannacia Diagnostics) was detected in serum (0.89 kU/1, CAP-RAST-FEIA class 2).

Statistical evaluation of the persistence of acquired hypersensitivity by standardized patch tests

Numerous studies have focused attention on the influence of various biological and environmental factors on contact hypersensitivity. In order to evaluate the persistence and/or modification of allergic contact sensitivity 10 a number of common contact sensitizers, the same standardized patch tests were repeated on 174 subjects with contact sensitivity after a lime lapse of 5 years (1987–1992). In 18.4% of the cases, 1 or more sensitivities were lost: 28.7% of the patients had a higher number of positive patch tests after 5 years, while the remaining 52.9% of the patients showed no change in the number of positive patch tests. In 88%, the positive allergens were unchanged, whereas in the remaining 12% of the subjects, they showed 1 or more variations. The association between the allergens most often positive was calculated for both the 1st and the 2nd patch lest results. Moreover, to evaluate the frequency of an allergens positivity. We studied the disappearance of old sensitivities and the appearance of new sensitivities by the McNemar test. Cobalt chloride was the only allergen with a significant frequency of new positivities over the period of observation (p < 0.01). Logistic regression analysis was performed to evaluate the possible influence of positive tests to other allergens, and of some clinical findings associated with contact dermatitis, on the sensitivity to cobalt chloride in 1987 and in 1992.

Contact sensitivity to ‘advanced’ wound dressings in 116 patients with leg ulcers

The aim of our study was to investigate contact allergy in a group of 116 patients with leg ulcers (venous, arterial, and diabetic). Patients were patch tested to the SIDAPA (Italian Society of Allergological Professional and Environmental Dermatology) baseline series (8-mm Finn Chambers on Scanpor tape, readings at D2, D3, and D7 according to International Contact Dermatitis Research Group guidelines) and an extensive leg ulcer series consisting of 40 substances (Euromedical Diagnostics, Italy) most of which were patch tested ‘as is’. Positive reactions were seen in 71 (61%) patients with a total number of 204 allergic reactions. There were 191 reactions to allergens in the baseline series and 13 on the leg ulcer series, including 5 to modern wound dressings. Three patients were positive to hydrogel, caused by sensitization to propylene glycol in two cases. In one patient, the allergen was not identified. No hydrogel was labelled as containing propylene glycol, but based on our and published data, the most likely allergen in this type of product is propylene glycol as 60% of patients allergic to hydrogel were also allergic to propylene glycol (4). Two patients were allergic to butyl methacrylate and methyl methacrylate used in the adhesive border of a multilayered polyurethane dressing.