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

A novel arctigenin-containing latex glove prevents latex allergy by inhibiting type I/IV allergic reactions

The present study aimed at developing a natural compound with anti-allergic effect and stability under latex glove manufacturing conditions and investigating whether its anti-allergic effect is maintained after its addition into the latex. The effects of nine natural compounds on growth of the RBL-2H3 cells and mouse primary spleen lymphocytes were determined using MTT assay. The compounds included glycyrrhizin, osthole, tetrandrine, tea polyphenol, catechin, arctigenin, oleanolic acid, baicalin and oxymatrine. An ELISA assay was used for the in vitro anti-type I/IV allergy screening; in this process β-hexosaminidase, histamine, and IL-4 released from RBL-2H3 cell lines and IFN-γ and IL-2 released from mouse primary spleen lymphocytes were taken as screening indices. The physical stability of eight natural compounds and the dissolubility of arctigenin, selected based on the in vitro pharnacodynamaic screening and the stability evaluation, were detected by HPLC. The in vivo pharmacodynamic confirmation of arctigenin and final latex product was evaluated with a passive cutaneous anaphylaxis (PCA) model and an allergen-specific skin response model. Nine natural compounds showed minor growth inhibition on RBL-2H3 cells and mouse primary spleen lymphocytes. Baicalin and arctigenin had the best anti-type I and IV allergic effects among the natural compounds based on the in vitro pharmacodynamic screening. Arctigenin and catechin had the best physical stability under different manufacturing conditions. Arctigenin was the selected for further evaluation and proven to have anti-type I and IV allergic effects in vivo in a dose-dependent manner. The final product of the arctigenin-containing latex glove had anti-type I and IV allergic effects in vivo which were mainly attributed to arctigenin as proved from the dissolubility results. Arctigenin showed anti-type I and IV allergic effects in vitro and in vivo, with a good stability under latex glove manufacturing conditions, and a persistent anti-allergic effect after being added into the latex to prevent latex allergy.

Natural rubber latex allergy: implications for the orthodontist

Natural rubber latex (NRL) allergy can have potentially serious consequences, and reports of orthodontic patients reacting to NRL have increased significantly over recent years. It is therefore important for the orthodontist to know how to manage patients with an NRL allergy and how to deal with possible reactions to NRL. Safe and effective practice depends on recognizing patients who are at risk of NRL allergy, and an awareness of materials and equipment that contain NRL and the availability of suitable NRL-free alternatives.

Latex medical gloves: time for a reappraisal

Many hospitals have implemented policies to restrict or ban the use of devices made of natural rubber latex (NRL) in healthcare as precautionary measures against the perceived risk of NRL allergy. Changes in glove technology, progress in measuring the specific allergenic potential of gloves and a dramatic decrease in the prevalence of NRL allergies after interventions and education prompted us to revisit the basis for justifiable glove selection policies. The published Anglophone literature from 1990 to 2010 was reviewed for original articles and reviews dealing with the barrier and performance properties of NRL and synthetic gloves and the role of glove powder. The review shows that NRL medical gloves, when compared with synthetic gloves, tend to be stronger, more flexible and better accepted by clinicians. The introduction of powder-free gloves has been associated with reductions in protein content and associated allergies. Recently, new methods to quantify clinically relevant NRL allergens have enabled the identification of gloves with low allergenic potential. The use of low-protein, low-allergenic, powder-free gloves is associated with a significant decrease in the prevalence of type I allergic reactions to NRL among healthcare workers. Given the excellent barrier properties and operating characteristics, dramatically reduced incidences of allergic reactions, availability of specific tests for selection of low-allergen gloves, competitive costs and low environmental impact, the use of NRL gloves within the hospital environment warrants reappraisal.

Innovative management of severe hand dermatitis

The successful treatment of hand dermatitis (HD) depends less on the selection of the proper topical steroid or a particular systemic agent than on addressing any underlying cause or perpetuating factor. Thus, innovative treatment is based on comprehensively addressing the patient's problem. Aggressive approaches may be required for the most severe forms of HD.

Other Allergic Skin Disorders

In this chapter we discuss allergic skin disorders other than atopic dermatitis (AD): the urticaria-angioedema syndrome, allergic contact dermatitis (ACD), protein contact dermatitis (PCD), phytodermatitis, allergic photodermatitis and allergic vasculitis.

Allergic skin disease: investigation of both immediate- and delayed-type hypersensitivity is essential

BACKGROUND

In our clinic we routinely patch test patients referred from occupational health for the investigation of latex contact urticaria. We also undertake both patch and prick testing (where indicated) in patients referred with persistent dermatitis/eczema. If investigation of allergic skin disease is undertaken by a non-dermatologist, it is unlikely that patch testing will be performed.

OBJECTIVE

To carry out a retrospective analysis of patients who had been prick tested to establish whether an incomplete diagnosis would have been reached if patch testing had been omitted.

METHODS

Details of patients who had attended for patch testing between July 2004 and December 2005 were analysed. Patients who had had prick tests and patch testing were identified. The outcomes of prick tests and patch testing were documented together with the clinical relevance.

RESULTS

Three hundred and thirty out of 1060 patients referred to the clinic were prick tested. 54.2% patients were referred from dermatologists. 26.6% were referred from occupational health, 68 patients had positive reactions on prick testing of whom 36 had positive patch tests (52.9%), which were of current relevance in 27 patients (39.7%). Nine out of 106 health workers referred to exclude latex contact urticaria had positive prick tests to latex. Fifty of these patients demonstrated delayed-type hypersensitivity with nickel, cobalt, rubber and its additives being the most common allergens found. Of the 262 patients who had negative prick tests, 121 had positive patch tests (46.1%) of current relevance to patient history in 92 subjects (35.1%). While none of the six patients referred for investigation of reaction to local anaesthetics had a positive prick test, one was allergic to local anaesthetic on patch testing.

CONCLUSION

Omission of patch testing from the investigation of allergic skin disease, even when contact urticaria may be the sole suspected diagnosis, would result in the frequent missed diagnosis of contact allergy. We recommend that patients with suspected allergic skin disease are investigated in an environment where investigation of both immediate- and delayed-type hypersensitivity can be undertaken. In particular, patients with atopic eczema, suspected latex rubber allergy, hand dermatitis (particularly occupational) and drug reactions should be targeted to receive both investigations.

Erythema multiforme-like eruption due to carbamates and thiuram

Report of a case of erythema multiforme-like eruption due to the use of rubber gloves. After several complementary studies, including epicutaneous and skin prick tests, we concluded that the eruption was secondary to sensitization to carbamates and thiuram. The main differential diagnosis in this case was allergic contact dermatitis to latex in natural rubber gloves. This entity is less frequent than might be expected, because it is usually due to intermediate chemical compounds used in rubber manufacturing, such as vulcanization accelerators; among of these latter compounds are thiurams and carbamates. Erythema multiforme-like eruption is a rare manifestation of contact dermatitis. Several cases have been reported, most of which have been due to contact with plants, metals or topical non-steroidal anti-inflammatory drugs. Its mechanism is still unclear, but it seems to be a type IV hypersensitivity reaction.

Prevention of latex allergy among health care workers and in the general population: latex protein content in devices commonly used in hospitals and general practice

BACKGROUND

In this study the latex protein content in devices commonly used in hospitals and general practice were investigated. The main aim was to acquire information for preventing latex allergy in health care workers and in the general population.

METHODS

About 22 different types of medical devices and 23 devices commonly used in general practice were examined evaluating the total allergenic potency by a modified RAST-inhibition assay and quantitative determination of single allergens (Hev b1, Hev b5 and Hev b6.02) by using commercial ELISA kit.

RESULTS

A high level of inhibition was found in medical devices, such as elastic bandage (81.57%), tourniquet (74.09%), Foley urinary catheter (68.35%), Penrose drainage (67.25%) and taping (39.6%), and in common devices, such as rubber inner-sole (84.20%), toy balloon (78.62%), latex mattress (74.27%), household rubber gloves (49.10%), working gloves (38.25%), inflatable floating mattress (32.10%). Concentrations of latex extractable proteins and Hev b1, Hev b5 and Hev b6.02 antigens were high in some medical and general devices.

CONCLUSIONS

Latex exposure sources were found in hospitals and the home. These findings, though only preliminary and far from conclusive, could enable sensitized persons to avoid risky exposures and prevent allergic reactions. From the point of view of prevention, the time may come when every natural rubber object could be systematically labelled as "containing latex" together with the warning that "this item may cause allergic reactions in sensitized subjects."

Allergic contact dermatitis from natural rubber latex in atopic dermatitis and the risk of later Type I allergy

The aims of the study were to assess whether contact dermatitis in children could be due to a delayed hypersensitivity reaction to natural rubber latex (NRL) and to define risk factors for later occurrence of Type I hypersensitivity to this allergen. Among 1800 children investigated for contact dermatitis, 55 were referred on suspicion of rubber allergy and had patch tests to NRL, as well as prick tests and blood tests for specific immunoglobulin E (IgE). A 2-year follow-up was then carried out. Delayed hypersensitivity to NRL was confirmed in 32 children. Patch testing with NRL proved to be positive, and clinical improvement confirmed the diagnosis and relevance of patch tests. 30 of these 32 patients had associated atopic dermatitis (AD). Prick tests and blood tests for specific IgE to latex were negative at the time of diagnosis. A 2-year follow-up showed that 10 of 27 patients presenting initially with a positive patch test without associated Type I sensitization later developed immediate hypersensitivity. Children with AD are at high risk for allergy to NRL protein. Exclusion of this allergen should be strongly advised in atopics because of the dual risk of dermatitis and later evolution into severe Type I hypersensitivity.

Occupation-related allergies in dentistry

BACKGROUND

Allergies to natural rubber latex (NRL) were unknown in dentistry until 1987. That changed with the publication of a report documenting NRL-based anaphylaxis in a dental worker. This case and others prompted regulatory and manufacturing changes in rubber products and increased awareness throughout the profession. However, other common dental chemicals cause allergic reactions and irritation and often are handled with insufficient precautions. Although recognition of NRL allergy has improved, awareness of other potential allergens and irritants in dentistry still is limited.

OVERVIEW

Recent research indicates that the prevalence of NRL protein allergy may be decreasing. In contrast, occupation-related dermatoses associated with other dental products may be more common. Encounters with bonding agents, disinfectants, rubber, metals and detergents can cause occupation-based irritant contact dermatitis and allergic contact dermatitis. These conditions may be found in more than one-quarter of dental and medical personnel. Therefore, dental-specific information about the recognition and management of allergic and irritant reactions is needed.

CONCLUSIONS AND CLINICAL IMPLICATIONS

The prevalence of occupation-related dermatitis may be increasing in dentistry. Reducing exposure to potential irritants and allergens and educating personnel about proper skin care are essential to reversing this trend.

Occupational allergens in dentistry

PURPOSE OF REVIEW

Dental professionals and their physicians frequently do not recognize, accurately diagnose or appropriately manage occupational allergies. Dental allergen identification, diagnostics and practical avoidance strategies are summarized in this review.

RECENT FINDINGS

Methacrylates, natural rubber latex proteins, rubber glove allergens, and glutaraldehyde are the predominant allergens in dentistry. Reactions range from cell-mediated contact allergy to urticaria and occupational asthma.

SUMMARY

Despite recent advances in allergen characterization and increased awareness of selected allergens, treatment of occupational allergies can be improved. Better information and improved cooperation between dental workers and their clinicians is needed.

Toxicological and immunological aspects of occupational latex allergy

Latex allergy continues to be an important occupational health problem as latex products are used increasingly worldwide, particularly in healthcare. Although there are few epidemiological studies on the incidence of latex allergy, there has been an increase in the number of case reports over the last 10 years and, based on skin-prick tests, estimates of prevalence of latex allergy in healthcare workers range from 2% to 17%. The allergic health effects arise either from the latex proteins, generally causing a type I immediate hypersensitivity reaction, or from the chemicals added to latex during processing, causing a type IV delayed hypersensitivity reaction. Clinical manifestations of latex allergy depend on the route of exposure and occur by direct contact either with skin or mucosa, or by inhalation. The diagnosis of latex allergy is based on the history, skin tests, serological tests and challenge tests. Thirteen latex allergens have been identified and isolated so far from natural rubber latex. They differ in their potential to elicit immunological responses in individuals allergic to latex and thus have been designated as major or minor allergens. In latex gloves, cornstarch powder used as a donning agent carries latex proteins, thereby increasing inhalational and mucosal exposure to latex proteins. There also appears to be a positive correlation between protein content and allergenicity of gloves. The use of powder-free, low-protein gloves is effective in reducing symptoms and markers of sensitisation. Alternatives to latex gloves, such as nitrile or vinyl gloves are available but may be inferior in respect to manual dexterity and biological impermeability.

Latex allergy: diagnosis and management

Latex allergy is an IgE-mediated immediate hypersensitivity response to natural rubber latex (NRL) protein with a variety of clinical signs ranging from contact urticaria, angioedema, asthma, and anaphylaxis. Major allergens include dipped latex products such as gloves and balloons. In highest risk for NRL allergy are patients with spina bifida, but health care workers and others who wear latex gloves are also at risk. NRL allergic patients may also react to fruits/foods, especially banana, kiwi, and avocado. Diagnosis is made by a positive latex RAST and/or skin prick test or challenge test to NRL. Allergen avoidance and substitution and the use of latex-safe devices including synthetic gloves (vinyl, synthetic polyisoprene, neoprene, nitrile, block polymers, or polyurethane) are essential for the affected patient. Accommodation in the workplace may include the use of powder-free, low-allergen NRL gloves or synthetic gloves. These preventive measures have significantly reduced the prevalence of reported reactions to NRL. Hyposensitization is not yet feasible.

Latex allergy and skin

PURPOSE OF REVIEW

In this review we address the prevalence and outcome of latex allergy in health care workers (HCWs). Recent findings in natural rubber latex (NRL) allergens and trials of specific immunotherapy (SIT) are also of interest.

RECENT FINDINGS

A study involving skin prick test (SPT) screening in HCWs in Russia and adjacent countries found a prevalence of latex allergy of 1.9%. Questionnaire studies performed in Wales and in the USA identified prevalence rates of about 0.6%. An intervention undertaken at the Mayo Clinic, in which only gloves with low or undetectable allergen levels were allowed, reduced markedly the incidence of NRL allergy. Two studies, one from Finland and another from Ohio, showed that outcomes in latex-allergic HCWs are generally good. A study involving SPT screening showed that 6% of construction workers had latex allergy. A questionnaire study among allergists practicing in the USA showed that 62% performed latex SPT and 6% reported anaphylaxis, which mostly occurred while using a homemade SPT solution. Hev b 2, Hev b 5, Hev b 6.01 and Hev b 13 produced positive SPT reactions in over 60% of latex-allergic individuals. Topical application of NRL in a murine model of protein contact dermatitis caused a striking increase in prohevein-specific (Hev b 6.01) immunoglobulin E levels, together with a T-helper-2 type dermatitis. A placebo-controlled SIT trial with NRL extract alleviated cutaneous symptoms but caused some systemic reactions in latex-allergic patients.

SUMMARY

Low prevalence rates suggest that the peak of the latex allergy epidemic has already passed in HCWs. Hospital-wide interventions requiring use of low-allergen gloves reduce sensitization and changing gloves to nonlatex ones, or even using low-allergen latex gloves, in the affected individuals appears to confer adequate secondary prevention. In the USA there is an urgent need for standardized latex SPT reagent. Hev b 5 and Hev b 6.01 are major in vivo NRL allergens. Findings in mice suggest that NRL proteins eluting from latex gloves may also cause hand eczema in humans. SIT with NRL extract must still be considered an experimental treatment.

Decreasing incidence of occupational contact urticaria caused by natural rubber latex allergy in German health care workers

BACKGROUND

The development of allergy to natural rubber latex (NRL) is a risk for health care workers. A regulation banning powdered NRL gloves was implemented in Germany in 1998.

OBJECTIVE

This study assesses the effects of this regulation on the development of occupational skin disease caused by NRL in health care personnel working in facilities insured by the German statutory accident insurance company, covering some 1.8 million insured health care workers.

METHODS

We reviewed the annual numbers of reported suspected cases of NRL-induced occupational allergies (mainly contact urticaria) from 1996 through 2002, as well as the number and type of gloves purchased in acute-care hospitals from 1986 through 2002.

RESULTS

The number of purchased nonsterile examination gloves increased by 1387% between 1986 and 2002. The purchase of powder-free NRL examination gloves exceeded that of powdered gloves in 1998. The incidence of suspected cases increased until 1998 and has since decreased by 79.9%. Most suspected cases (67.9%) were identified as occupationally caused.

CONCLUSIONS

Reducing the purchase of powdered NRL gloves is associated with a decrease in suspected and proved cases of occupational contact urticaria caused by NRL. Development of occupationally caused contact urticaria by NRL can be reduced by banning the use of powdered NRL gloves.

[Contact urticaria to natural rubber latex in childhood and associated atopic symptoms: a study of 27 patients aged under 15 years]

BACKGROUND

Although natural rubber latex hypersensitivity is considered as a major problem in adult, it may be still misdiagnosed in childhood.

PATIENTS AND METHOD

We collected 27 observations of natural rubber latex contact urticaria in children under 15 Years of age, 21 of them aged under 8.

RESULTS

All of them where atopic and 19 out of 27 presented with other association paroxystic signs of immediate hypersensitivity, that were lately related to latex allergy (i. e. asthma, rhinitis, conjunctivitis, fainting). Cross-allergy to food allergens was present in 33 p. 100. Average level of specific IgE to natural rubber latex was 21.7 kU/l. One to 4 Years follow up confirmed the benefit of latex eviction on urticaria as well as on associated symptoms. It led to the early detection of ficus allergy in 4 of them.

DISCUSSION

This series confirms that atopy is at high risk for natural rubber latex allergy in children. These data suggest that atopic children are exposed too early to latex devices such as pacifiers, toodles of latex toys. Contact urticaria in children must be considered as a possible marker of other respiratory or general symptoms that may have been misconsidered under other etiologies.

Latex allergy

The prevalence of IgE mediated natural latex rubber allergy is estimated to be < 1% in the general population, < 17% in medical personnel and approximately 0% in children with spina bifida. We review the definition, diagnosis, prevention, and treatment of NLR allergy.

Recent developments in latex allergy

PURPOSE OF REVIEW

Immediate allergic reactions to natural rubber latex continue to be an important medical and occupational health problem. In this review we focus on progress made in understanding the significance of occupational exposure and epidemiology, risk groups, diagnosis and prevention of natural rubber latex allergy. We also discuss methods aimed at quantification of clinically relevant natural rubber latex allergens and studies on B-cell epitopes of major natural rubber latex allergens.

RECENT FINDINGS

Prospective studies have been published focusing on the prevention of natural rubber latex allergy. Efforts to identify and characterize new natural rubber latex allergens were continued in several research groups. The use of purified allergens or proteins produced by recombinant DNA technology was assessed in studies aimed at improving the diagnosis of natural rubber latex allergy as well as in developing quantitative methods for the measurement of specific natural rubber latex allergens. For the first time, conformational immunoglobulin E epitopes were identified in a major natural rubber latex allergen, hevein, using a novel chimera-based allergen epitope mapping strategy.

SUMMARY

Measures taken in health care to reduce exposure to natural rubber latex products seem to be effective in reducing the number of new sensitizations. A few new minor natural rubber latex allergens, probably important in allergen cross reactions, were identified, and some nonmedical natural rubber latex products were found to be potentially dangerous to natural rubber latex-allergic patients. Sensitive and specific immunoassays for quantification of clinically relevant natural rubber latex allergens in manufactured products were developed in some laboratories. These assays may eventually replace the nonspecific total protein measurement, currently advocated by health authorities in the indirect estimation of allergen amounts in natural rubber latex products. Knowledge about conformational immunoglobulin-binding B-cell epitopes of major allergens is expected to be helpful in designing optimal reagents to specific immunotherapy.