Luis Conde-Salazar

Thoughts on sensitizers in a standard patch test series

Patch testing is the predominant method of establishing contact allergy. The present patch test technique is the result of a continuous process of development and improvement since its first application in the late 19th century. The perfect patch test should give no false‐positive and no false‐negative reactions. The ideal patch test should also cause as few adverse reactions as possible, particularly no patch test sensitization. Even though the history and examination of a patient with suspected allergic contact dermatitis will give clues to possible sensitizers, it is not suffcient t to patch test only with initially suspected sensitizers; unsuspected sensitizers used for patch testing frequently turn out to be the real cause of the dermatitis. Fortunately, a small number of substances are considered to account for the majority of delayed hypersensitivity reactions. Therefore, generally 20–25 test preparations consisting of chemically dened compounds, mixes of allergens, and natural and synthetic compounds, are grouped into a standard test series. The requirements to be fullled by a sensitizer in a standard patch test series are discussed in this article. A procedure of investigations is proposed before a sensitizer is included in a standard series.

Type IV allergy to rubber additives: A 10-year study of 686 cases

BACKGROUND Rubber additives, mainly vulcanizers and antioxidants, are increasingly a cause of contact dermatitis. OBJECTIVE The aim of the present study was to determine the frequency of type IV allergy to rubber additives. METHODS Seven thousand patients seen during a 10-year period were evaluated. Of them, 4680 were patch tested with the standard series recommended by the Spanish Group for Research of Contact Dermatitis (GEIDC) and a series of individual rubber additives. RESULTS A total of 686 patients (14.7% of those patch tested) had one or more positive reactions to rubber additives. Of these, 582 (84.8%) were men and 104 (15.2%) were women. The incidence of rubber sensitization was especially high among construction workers (47.0%). CONCLUSION Rubber additives are a common cause of occupational contact dermatitis, particularly in construction workers. We postulate that rubber gloves and boots (utilized to avoid contact with sensitizing substances) themselves may be a common cause of contact dermatitis. The high incidence of allergy to some rubber additives, such as thiurams and carbas, indicates that their replacement by other less sensitizing vulcanizers is advisable.

Contact dermatitis in hairdressers, 10 years later: patch-test results in 300 hairdressers (1994 to 2003) and comparison with previous study.

Background: In the last 20 years, the hairdressing profession has undergone important modifications, mainly because of a change in the substances and techniques used and improved occupational education. Objective: To evaluate the modifications in the hairdressing profession and its actual risk of occupational allergic contact dermatitis (OACD). Methods: We studied all 300 hairdressers seen in our department from 1994 to 2003 and compared the results with those of a previous study of 379 hairdressers who attended our department from 1980 to 1993. All were patch‐tested with the European Standard series and specific hairdressing products. As previously, most of the workers were women (93%), with a mean age (23.7 years) slightly higher than that of the workers in our previous study. Results: We found a significant increase in the frequency of positive patch‐test responses (78.3% vs 58.8%) and OACD (58% vs 48.8%) with respect to our previous study. We also observed a significant increase in sensitization to most allergens, including p‐phenylenediamine base (54% vs 45.9%), 4‐aminobenzene (40.7% vs 31.9%), ammonium thioglycolate (2.7% to 12.3%), ammonium persulfate (7.9% to 14.3%), p‐toluenediamine sulfate (6.8% to 15.3%), p‐aminodiphenylamine (2.9% to 7.7%), o‐nitro‐4‐phenylenediamine (2.1% to 7.3%), and aminophenols (0% to 9%), whereas a decrease was found in sensitization to Disperse Orange (17% vs 32.7%) and thioglycolic acid (15.3% to 3%). Conclusion: The high frequency and increase of sensitizations among hairdressers require urgent measures to improve protective measures and their application.

Occupational allergic contact dermatitis in construction workers

We report the patch test results of 449 con in met ion workers who came as patients to tine Occupational Dermatology Service of the Instituto National de Medicina y Seguridad del Trabajo in Madrid between 1989 and 1993. 90.8%. of them were patch tested, because they had cutaneous lesions or a clinical history suggestive of occupational dermatitis. 65.5% (268) of those patch tested showed one or more reactions connected with their work. Chromate at 411 was the main allergen. followed by cobalt, 20.5% nickel. 10%, and epoxy resin. 7.5%. 25.9% (106) of patients showed sensitization to rubber components, the majority at 20.7%, to thiuram mix, with TETD being the main allergen.

Allergic contact urticaria from natural rubber latex in healthcare and non-healthcare workers

To compare the prevalence of natural rubber latex (NRL) sensitization and allergic contact urticaria from NRL in healthcare and non‐healthcare workers, we studied all 1171 patients who attended our clinic during 2001 and 2002. Prick testing for NRL and patch testing with European standard series were performed in all patients and an additional rubber series in those who had contact with rubber. Specific immunoglobulin E (IgE) levels against NRL and tropical fruits were measured when prick testing was positive. Sensitization to NRL (positive prick test and specific IgE levels) was much more common in healthcare workers than that in non‐healthcare workers, 16.7 versus 2.3%. Among the non‐healthcare workers, sensitization to NRL was more common in food handlers (17.1%), construction workers (6.6%), painters (6.2%), hairdressers (5.1%) and cleaners (3.8%). The difference in the prevalence of specific IgE to tropical fruits was not significant. Allergic contact urticaria from NRL was also much more frequent in healthcare workers, 71.4 versus 28.6%. In conclusion, sensitization to NRL and allergic contact urticaria from NRL are more common in healthcare workers, but this is a growing problem in non‐healthcare workers and should be investigated in all workers with a history of NRL intolerance or who have contact with NRL.

Contact urticaria caused by heat-sensitive raw fish allergens

Patients allergic to fish usually present with skin reactions after handling raw fish. Less frequently, these reactions are seen without symptoms after oral intake, often in chefs and food handlers. We have attempted to explain the skin selectivity of such reactions in a 36‐year‐old woman with contact urticaria after handling raw fish. We obtained aqueous extracts of raw and cooked fish (sole and hake) for in vivo (prick test) and in vitro (SDS‐PAGE, IgE Immunoblot) tests. Prick‐by‐prick test, 20‐min closed patch test, rub test with fresh and cooked fish (sole, hake and cod) and specific IgE (CAP‐system) to sole, cod and hake were performed. The strength of positive reaction to raw fish was greater than to cooked fish on both prick and prick‐by‐prick testing. Rub tests showed positive responses only to raw fish. Specific IgEs to sole (45 KU/l), hake (66.9 KU/l) and cod (18.7 KU/l) were obtained. IgE immunoblot recognized 3 antigens of 25, 48, 56 kDa in raw sole and 1 of 42 kDa in raw hake extracts. No IgE binding was observed with the cooked extracts or control sera. Our findings strongly suggest a Type‐I hypersensitivity to fish. Immunoblot analyses demonstrated a loss of specific IgE binding to cooked extracts. We have reported a case of contact urticaria caused by heat‐sensitive raw‐fish allergens in a patient who probably became sensitized via the cutaneous route.

Type I and Type IV sensitization to Anisakis simplex in 2 patients with hand eczema

A 34-year-old cook had had eczematous lesions on his face, hands and feet for a year before presentation. He also reported an episode of angioedema after eating a kiwi fruit. He was patch tested with the TRUE Test standard series and the Chemotechnique cosmetics and metals series. At D4 there were positive reactions to potassium dichromate, cobalt chloride, PPD and colophonium. These sensitivities were not related to his occupation. Total IgE was 750 and specific IgE for Anisakis simplex was 90.1kU/ mL. Specific IgE for mussel and fresh anchovy was less than 0.35kU/mL. Prick tests to Anisakis simplex and kiwi fruit were positive. Histamine release was positive to Anisakis simplex and negative to avocado, kiwi fruit and natural rubber latex. Table1. Results of patch tests with Anisakis simplex larvae

Occupational airborne contact dermatitis from omeprazole

Omeprazole is a drug introduced in the market since 1979. It belongs to the benzimidazole group and acts as an inhibitor of the proton pump. It is administered orally and has a wide use in the treatment of the peptic acid disease and Zollinger Ellison syndrome and as a protector of the gastric mucosae in patients with surgical stress and with background of taking multiple medications. Allergic contact dermatitis due to omeprazole has not been frequently reported. Meding (1) in 1986 reported for the first time 2 occupational cases in pharmaceutical workers. Lesions were localized to the eyelids, and patch testing showed positive reactions to omeprazole. The concentrations of omeprazole used in 1 patient were 0.25%, 0.5%, and 1% in pet. Control test with omeprazole 0.5% in pet. in 10 persons were negative. The second patient was tested with omeprazole 0.1%, 0.5%, and 1% in alcohol. Control test with omeprazole 0.5% in alcohol in 12 individuals were negative. After this report, we have no knowledge of any other cases of occupational dermatitis from omeprazole.

Latex allergy among construction workers

To assess the incidence of latex allergy in construction workers, we studied all the 230 construction workers who attended our clinic between 1996 and 2000. In the 54 (23.5%) patients who reported any kind of intolerance to rubber gloves or boots, we performed both patch testing with the TRUE TestTM standard series and a rubber series and prick testing for latex. Latex‐specific IgE levels were measured when prick testing was positive. 16 patients (7.0%) had a positive prick test to latex, of whom 14 had allergic contact urticaria from latex (ACUL). All of these 14 patients (6.1%) showed 1 or more positive reactions to the True Test series, which included 1 or more rubber chemicals in 9 of them. The level of specific Ig E to latex was greater than 0.35 kU/L in 15 of the 16 patients. In conclusion, our data suggest that the incidence of latex allergic contact urticaria among construction workers may be as high as that among health care workers. Most of these construction workers with Type I latex hypersensitivity had a concurrent Type IV hypersensitivity to chromate or rubber chemicals, presenting as occupational allergic contact dermatitis, which could have facilitated sensitization to latex.

Occupational allergic contact dermatitis from cyanoacrylate

Cyanoacrylates are widely used in adhesive techniques. Cyanoacrylate adhesives differ physically for the different needs of application, and chemically in function of the size of ester molecules. A 40-year-old man employed at the National Mint and Stamp factory presented with hyperkeratotic lesions on the fingers of the right hand. His job consisted of fixing microchips to plastic phone cards with Loctite Series 414. Patch testing confirmed sensitivity to cyanoacrylates. After the diagnosis of allergic contact dermatitis was established, the patient, to be cured of the dermatitis, changed his workplace 2 months later.