Type IV hypersensitivity reactions to natural rubber latex: results of a multicentre study

BACKGROUND: Positive patch test reactions to natural rubber latex (NRL) have been interpreted as allergic or irritant by different groups. Additives to the NRL test solution have also caused positive reactions in previous studies. OBJECTIVES: Five centres of the British Contact Dermatitis Group conducted a prospective study on the prevalence of type IV hypersensitivity to NRL, using ammonia-preserved NRL solution for testing. PATIENTS AND METHODS: A total of 2738 consecutive patients were patch tested. Where clinically indicated, specific IgE was measured or a prick test done. RESULTS: Twenty-seven patients (1%) had a positive patch test reaction to NRL, which was considered to be allergic and of current relevance in 19 (70%) patients. Fourteen of these also had a positive prick test or specific IgE. Thirteen patients (48%) were male, 19 (70%) atopic and 13 (48%) had eczema on their hands. CONCLUSIONS: We conclude that delayed-type hypersensitivity to NRL is a problem for a proportion of patients with eczema, particularly on their hands, and that patch testing with ammonia-preserved NRL can be recommended to identify these patients. Patients with a positive patch test should be investigated for contact urticaria to NRL.     

Prevalence of natural rubber latex allergy (Type I and Type IV) in laboratory workers in The Netherlands

The objective of the study was to study the prevalence of Type IV and Type I allergy to natural rubber latex (NRL) in a population at risk in the Netherlands. Laboratory workers regularly using gloves were invited to complete a questionnaire and to be tested. We performed patch tests with standard contact allergens, rubber additives, glove powder and pieces of 4 gloves; prick tests with inhalant allergens, glove extracts, glove powder and fruit extracts; and RASTs. Glove-related hand dermatitis was reported in 36.9% of the individuals interviewed. A positive patch test result for rubber additives was seen in only 6.6%. Glove-related urticaria, rhinoconjunctivitis and/or asthma were reported in 24.6% of all cases. Confirmation of an IgE-mediated reaction was achieved in 8.3% by prick test with glove extracts and 5.0% by RAST No reaction to glove powder was noticed in patch testing or in prick testing. A high prevalence rate of glove-related symptoms and NRL Type I allergy was found in laboratory workers exposed to rubber gloves. Surprisingly, there was no co-existence of Type I and Type IV allergy in this population.     

Occupational protein contact dermatitis and paronychia from natural rubber latex

Protein contact dermatitis (PCD) is a chronic recurrent dermatitis caused by contact with a proteinaceous material. PCD may also present as paronychia. Here a case of PCD and paronychia from natural rubber latex (NRL) is presented. The correct diagnosis would not have been established if prick testing with NRL had not been performed. This case shows that contact allergy presenting as dermatitis may occur despite negative patch test results. PCD from NRL may be relatively common, although very few cases have been published. This is probably due to the fact that the term contact urticaria is so closely connected to NRL that automatically all cases of type I allergy to NRL are considered contact urticaria, although the clinical picture is a dermatitis, i.e. PCD.     

Condoms as a source of latex allergen and cause of contact urticaria

To examine the occurrence of latex allergen in condoms and to study the symptoms caused by contact with condoms, 46 patients with latex-glove contact urticaria (LGCU) were investigated. 7 (24%) of the 29 patients with a history of condom use had experienced local swelling and/or pruritus during intercourse, confirming that condoms can cause local symptoms in latex allergic subjects. Prick tests performed on 16 different condom brands showed that 4 brands caused positive reactions in 52–67% of patients. The remaining 12 brands were not as allergenic and 1 brand was totally negative on prick testing. 1 highly allergenic condom brand was examined by high-pressure liquid chromatography (HPLC), which showed similar protein profiles to those detectable in latex gloves and natural rubber. These results show that, in addition to rubber gloves and balloons, condoms should also be considered as possible sources of latex, and that patients with LGCU should be advised to avoid condoms.     

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.     

A study of natural rubber latex allergens in gloves used by healthcare workers in Singapore

BACKGROUND: Allergy to natural rubber latex (NRL) proteins is a well-recognized health problem among subjects using protective gloves and products made of NRL. There is currently no information on NRL allergen levels in gloves used in Singapore. OBJECTIVES: This study aims to quantify the amount of specific allergens (Hev b 1, Hev b 3, Hev b 5 and Hev b 6.02) found in rubber gloves used in Singapore. It also aims to determine if these levels are above thresholds that may cause NRL allergy. It also compares the levels of these specific allergens in gloves used for different purposes, namely gloves used for examination purposes or for surgical procedures. METHODS: Forty-nine rubber gloves were obtained from major hospitals and healthcare departments in Singapore and were analysed for their NRL allergen levels. FITkit, based on the enzyme immunometric assay technique, was used to determine the specific allergen levels of Hev b 1, Hev b 3, Hev b 5 and Hev b 6.02 in the gloves. RESULTS: Examination gloves had higher NRL allergen content compared with surgical gloves, and powdered gloves had higher allergen content compared with nonpowdered gloves. Among the various allergens, Hev b 5 and Hev b 6.02 were present in larger quantities than Hev b 1 and Hev b 3. Only two of 19 (11%) surgical gloves had the sum of the four allergens (Hev b 1, Hev b 3, Hev b 5, Hev b 6.02) in excess of 1 microg g(-1), which is believed to be a clinically relevant threshold. Among the examination gloves, 25 of 30 (83%) exceeded this level. CONCLUSIONS: This study shows that NRL allergen levels are present in the majority of examination gloves used by healthcare workers in Singapore at levels high enough to cause NRL allergy among sensitized persons. The information can serve as evidence for a possible requirement for manufacturers to produce gloves with low NRL allergen levels and to state the allergen level in gloves in the product information.     

台州市531例慢性荨麻疹过敏原检测

目的:筛选台州市531例慢性荨麻疹患者过敏原。方法:采用免疫印迹法对531例慢性荨麻疹患者进行过敏原测定。结果:吸入性过敏原阳性率为25.24%(134例),其中尘螨阳性率22.41%(119例);食人性过敏原阳性率为29.0%(154例),其中蟹抗体阳性率13.75%(73例)。结论:本地区常见过敏原为尘螨。