Adverse reactions to latex products: preventive and therapeutic strategies

Evidence-based infection control/exposure control practices are evolutionary in nature. Elements of historical note were first recorded with the suggestions of Lister for guidelines on aseptic procedures. Others, like Semmelweis, promoted the practice of hand washing by medical students and physicians prior to leaving autopsy suites and before entering the labor and delivery areas of hospitals. Halstead is credited with being the first to use surgical gloves in a clinical setting. While the use of latex surgical gloves became routine by the end of World War I, it wasn't until the adoption of universal precautions by the Centers for Disease Control in 1987 that the use of gloves was officially expanded to cover virtually all aspects of patient care. The ubiquitous use of latex gloves and other latex products in healthcare has resulted in a parallel increase in latex-associated adverse reactions. To provide for a safe environment for both oral healthcare providers and patients alike, clinicians must understand the basis for latex-related adverse reactions, recognize associated signs and symptoms, and initiate appropriate preventive and therapeutic strategies. The recommendations for preventing/minimizing latex allergy in the oral healthcare setting are based on current knowledge and a common sense approach to the problem. Evolving manufacturing technology and improvements in measurement methods (for latex proteins) may lead to changes in these recommendations in the future.

Advances in development of hypoallergenic latex immunotherapy

PURPOSE OF REVIEW

The characterization of clinically relevant latex allergens and the production of recombinant allergens is now well advanced, but this knowledge needs to be translated into new strategies for the safe and effective specific treatment of latex allergic diseases including asthma and anaphylaxis.

RECENT FINDINGS

The current status of latex allergy is discussed indicating a changing demographic paradigm. A new wave of latex allergy is emerging outside the healthcare setting with the widespread use of latex products. An increased prevalence in developing countries is also reported. Limited studies on current specific immunotherapy for latex allergy are reviewed, confirming the feasibility but demonstrating an unacceptable risk of adverse events. The characterization of latex allergens and the identification of B and T-cell epitopes point to rational strategies for the generation of hypoallergenic preparations for specific immunotherapy. Results to date for latex allergens are reviewed, including recombinant, chemical modification and synthetic peptide approaches. Candidate hypoallergenic preparations for targeting sensitization to the major allergens Hev b 1, Hev b 3, Hev b 5 and Hev b 6.01 have been identified. Further investigations of optimal regimens for the delivery of specific immunotherapy to induce regulatory T-cell function are warranted.

SUMMARY

The findings point to the selection of suitable hypoallergenic preparations for clinical trials of effective and safe latex allergy immunotherapy.

Latex allergy: a challenge for anaesthetists

First reported in 1979, anaesthetists now encounter more and more patients with latex allergy. Several risk groups prone to develop this allergy have been identified. A thorough preoperative interview is necessary to detect high-risk patients. For them, the perioperative period is very dangerous because of the many possibilities of contact with latex-containing materials. There is no cure for latex allergy. Absolute avoidance of contact with latex is the only safe way to treat those who belong to a risk group or who are already allergic. The diagnosis of latex allergy must be kept in mind in every case of perioperative anaphylaxis, even if the patient does not belong to a risk group. In the future, desensitization will probably be useful in helping patients with latex allergy.

[Preventive measures against health damage due to chemicals in household products]

Chemicals in household products have been paid much attention as main cause of health damage on consumers, such as allergic contact dermatitis. Preventive measures against health damage due to chemicals in fabric, plastic and rubber products for household uses, are reviewed, focusing on (1) regulation and voluntary control by manufacturers, (2) incidence of health damage from household products, (3) causative product-chemical investigation, (4) case studies on skin damage and respiratory tract damage.

[Four cases of pollen-food allergy syndrome suspected the cross reactivity including latex]

BACKGROUND

Generally it is recognized that the occurrence of fruit allergy is attributed not to the sensitization of itself but to the cross reactivity with pollens or latex. But the relationship as to the sensitization between pollen and latex is obscure. So we aimed to investigate the relation of sensitization among pollens, fruits and latex.

METHODS

We tried to examine latex-specific IgE titer and practice skin prick test of latex for the patients of pollen-food allergy syndrome.

RESULTS

It was confirmed that some patients of pollen-food allergy syndrome showed positive reactions against both specific IgE and skin prick test of latex, though they could tolerate latex products in their daily lives. We present here four patients of such clinical courses concretely.

CONCLUSION

The patients of pollen-food allergy syndrome should be practiced examination about latex allergy, even if they can use latex products without any symptoms. And more if positive results are obtained, additional examination such as immunoblot and IgE RAST inhibition test are recommended to practice in order to clarify the unresolved problems, such as 1) which factor is the major allergen to cause cross-reactivity among these three factors? 2) what occurs if patients of same clinical courses with our cases continue to use latex products? Further investigation will be indispensable to resolve these problems in the future.

Identification of Hevamine and Hev b 1 as Major Latex Allergens in Taiwan

BACKGROUND

Proteins from latex gloves have been documented to trigger occupational latex allergy among health care workers. Allergen characterization of latex glove extract has never been studied in Taiwan. This study aimed to identify allergenic proteins from latex gloves.

METHODS

Crude extracts of latex gloves were prepared with phosphate-buffered saline and 20 medical workers with a history of latex allergy were enrolled in this study. The specific IgE antibody was determined by the Pharmacia CAP system and in-house enzyme-linked immunoassay and immunoblotting. The target proteins were excised from two-dimensional PAGE and analyzed by electrospray ionization tandem mass spectrometry.

RESULTS

Immunoblotting of glove extracts revealed three IgE-binding proteins at a molecular mass of 45, 30 and 14 kDa. Peptide mass fingerprinting revealed that the protein at 45 kDa, which was recognized by 10% (2/20) of atopic sera tested, was an allergenic lipolytic esterase from Hevea brasiliensis (Hev b 13). The 30- and 14-kDa proteins, which were recognized by 55% (11/20) and 85% (17/20) of patients' sera, were found to be hevamine and rubber elongation factor (Hev b 1), respectively.

CONCLUSIONS

Our results indicated that hevamine and Hev b 1 are the major allergens from latex gloves in Taiwan, which differs from the reports in Western countries.

Impact of a latex policy on an acute NHS hospital: an audit

BACKGROUND

A latex policy was introduced in 1999 in a large, acute UK hospital.

AIM

To audit the impact of the policy.

METHOD

Semi-structured interview of the managers of 40 wards between April 2001 and July 2002.

RESULTS

A policy was available on only 26 (65%) of the wards. Compliance with the policy was limited to 20 (50%) wards.

CONCLUSIONS

Compliance with the policy was low in the hospital. Staff and patients are being unnecessarily exposed to the hazard of latex.

[Effect of silicon and latex urinary catheters: a comparative study]

OBJECTIVE

To evaluate the effect of silicon and latex urinary catheters on urinary mucosa.

METHODS

A randomized, controlled prospective clinical trial was carried out in 60 patients admitted in the Department of Neurosurgery, who required long-term use of an indwelling urinary catheter. The patients were divided into 2 equal groups with placement of silicon or latex urinary catheter, and routine laboratory urine test was performed on a regular basis and the patients feelings during catheter retention were recorded.

RESULTS

Patients with placement of indwelling silicone catheters reported no obvious discomfort in relation to the catheter placement and had significantly lower incidence of hematuria identified microscopically than those with common latex catheters.

CONCLUSION

Compared with latex catheters, silicone catheters cause less injuries and reduce substantially irritation of the urinary mucosa, and we suggest the use of silicone catheter in patients requiring long-term indwelling urinary catheters.

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.

Investigative methods for natural rubber latex allergy in the UK

Allergy to natural rubber latex (NRL) has become an important health issue in recent years, but little is known about how this condition is investigated by physicians in the UK. This postal questionnaire of British dermatology and allergy specialists shows substantial variation in diagnostic practice, most notably with regard to the utilization and choice of starting dose of commercial latex prick test dilutions, reliance on allergen-specific immunoglobulin E measurement, investigation of associated fruit allergy and provision of resuscitation equipment/method of consent when challenge testing. 17% of responding physicians who investigate for NRL allergy do not perform prick test or glove challenge because of the potential risk of anaphylaxis or lack of resuscitation facilities. 87% of allergy clinic specialists report no reduction in the number of patients presenting as new referrals with suspected NRL allergy. These findings suggest a need for robust guidance to achieve more consistent investigative practice by those dealing with this condition.

It's just "balloon-acy"! The hidden dangers of latex allergy

Individuals most at risk for latex allergy are workers with ongoing latex exposure, such as health care workers who often encounter latex gloves on the job. Latex exposure can occur through skin contact or by inhaling aerosolized latex particles. Similar to latex gloves, latex balloons are packed in powder for shipping and when they are inflated, the latex particles attached to the powder become aerosolized, creating an environmental hazard for individuals with latex allergy. Hospital administrations are following a national trend to prohibit latex balloons from the hospital environment and replace them with Mylar or a non-latex containing balloon.

Vaccination of persons allergic to latex: a review of safety data in the Vaccine Adverse Event Reporting System (VAERS)

Vaccine products currently licensed in the US and other countries are marketed in vials and syringes that may contain natural latex allergens. Little scientific information exists regarding the safety of vaccination of latex-allergic individuals. A review of data within the Vaccine Adverse Event Reporting System (VAERS), a large registry of reported possible vaccine adverse reactions was conducted. A search of the database, which contains >160,000 vaccine adverse event reports, revealed only 28 cases of possible immediate-type hypersensitivity reactions in vaccine recipients with a history of allergy to latex. Given the large number of immunizations administered every year in the US, the reported risk of allergic reactions possibly due to latex contamination of vaccines appears to be very small.

Latex allergen exposure increases exhaled nitric oxide in symptomatic healthcare workers

The objective of this study was to investigate the clinical and diagnostic impact of baseline exhaled nitric oxide (eNO) levels and latex allergen-induced eNO changes in different healthcare worker groups. Healthcare workers, 31 latex-sensitised and 14 nonsensitised, underwent occupational-type challenge tests with powdered allergenic latex gloves. Sensitised as well as nonsensitised healthcare workers developed a significant eNO increase 1 h after challenge. Conversely, only latex-sensitised employees showed a significant eNO increase 22 h after challenge, which showed a significant relationship with bronchial obstruction (specific airway resistance changes). However, there was no difference in either baseline eNO level or eNO increase after 22 h between asthmatic (n = 13) and rhinitic only (n = 20) responders. The specificity and sensitivity of a 50% eNO increase after 22 h in responders were 100 and 56%, respectively. These results support the assumption that the whole respiratory tract is involved in a combined allergic rhinitis and asthma syndrome. Smoking healthcare workers showed reduced baseline exhaled nitric oxide levels, but, as shown for the first time, an allergen-induced exhaled nitric oxide increase comparable to that of nonsmokers. Corticosteroid therapy inhibited the allergen-induced exhaled nitric oxide change but not the clinical response in the challenge test. These findings suggest that cigarette smoke and corticosteroids initiate distinct molecular mechanisms influencing nitric oxide concentrations in the airways.

Indirect latex glove contamination and its inhibitory effect on vinyl polysiloxane polymerization

STATEMENT OF PROBLEM

The inhibitory effect of indirect latex contamination on the polymerization of vinyl polysiloxane (VPS) impression material has been previously reported. However, the transfer of specific elements that cause inhibition has not been confirmed, nor has the removal of such contaminants been reported.

PURPOSE

This study examined the surfaces of materials commonly used in restorative procedures that were contaminated by indirect latex glove contact and then evaluated for inhibition of polymerization of VPS. The effect of selected cleansing procedures was then studied.

MATERIAL AND METHODS

Four experimental groups (n = 8) were prepared: (1) clean vinyl gloves (control), (2) clean gingival retraction cords (control), (3) contaminated vinyl gloves, and (4) contaminated gingival retraction cord. Microscopic evaluation of the appearance and the characterization of surface particulate contamination were performed for each. Three cleansing protocols were then evaluated for efficacy in cleaning vinyl glove surfaces contaminated by latex contact (n = 10): (1) brushing with water, (2) brushing with soap/rinsing with water, (3) cleansing with rubbing alcohol. The subsequent degree of VPS polymerization inhibition was evaluated subjectively. A chi-square test was used for data analysis (alpha=.05).

RESULTS

Particulate sulfur elements and sulfur-chloride compounds were present on the contaminated substrates. None of the 3 cleansing procedures eliminated polymerization inhibition (P =.33). Residual elemental sulfur remained on all tested surfaces.

CONCLUSION

Particulate sulfur and sulfur-chloride compounds were identified as the particulate contamination that resulted in polymerization inhibition of the tested VPS dental impression material. Removal of these contaminants from the tested vinyl gloves and gingival retraction cord was not possible with the 3 cleansing protocols tested in this study.

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.

Work-related asthma among health care workers: surveillance data from California, Massachusetts, Michigan, and New Jersey, 1993-1997

BACKGROUND

Asthma morbidity has increased, posing a public health burden. Work-related asthma (WRA) accounts for a significant proportion of adult asthma that causes serious personal and economic consequences.

METHODS

Cases were identified using physician reports and hospital discharge data, as part of four state-based surveillance systems. We used structured interviews to confirm cases and identify occupations and exposures associated with WRA.

RESULTS

Health care workers (HCWs) accounted for 16% (n = 305) of the 1,879 confirmed WRA cases, but only 8% of the states' workforce. Cases primarily were employed in hospitals and were nurses. The most commonly reported exposures were cleaning products, latex, and poor air quality.

CONCLUSIONS

Health care workers are at risk for work-related asthma. Health care providers need to recognize this risk of WRA, as early diagnosis will decrease the morbidity associated with WRA. Careful product purchasing and facility maintenance by health care institutions will decrease the risk.

Latex-vegetable syndrome due to custard apple and aubergine: new variations of the hevein symphony

An increasing number of vegetables with crossreactions to latex are being described in patients with latex-vegetable syndrome. We present two of these vegetables, custard apple linked in two previous cases with latex sensitisation, and aubergine, that had not been described up to now in patients with latex sensitisation. The diagnosis of both cases was based on the clinical history, positive skin prick test (SPT) and specific IgE to the offending vegetables, as well as to positive SPT and specific IgE levels to latex and the major fruits involved in the latex-fruit syndrome (avocado, banana, and chestnut). Further, crude extracts from latex, custard apple and aubergine, as well as the purified allergens Hev b 6.02 and Prs a 1 were used in in vitro and in vivo assays: IgE immunodetection, histamine release (HRT) and basophil activation (BAT) tests and skin prick tests. In case 1, both purified Hev b 6.02 and Prs a 1 induced positive responses in skin prick tests, high levels of basophil activation and histamine release. Specific IgE immunodetection uncovered a reactive band of 45 kd in the crude custard apple extract, which was also recognized by anti-chitinase monospecific antibodies. The serum from patient 1 also detected Prs a 1 in immunodetection. Hev b 6.02 produced positive skin responses and showed high biological activity in HRT and BAT in the case of patient 2. However, Prs a 1 was reactive neither in SPT nor in IgE immunodetection. In fact, no band was detected using the serum of patient 2 in avocado or aubergine extracts. By contrast, Prs a 1 reached high values of basophil activation and over 10% of histamine release in case 2.

Calotropis procera (ushaar) keratitis

PURPOSE

To report a case of permanent endothelial cell injury after intracorneal penetration of milky latex from Calotropis procera (ushaar).

DESIGN

Interventional case report.

METHODS

A 40-year-old patient developed painless corneal edema despite minimal epithelial injury after exposure to ushaar latex.

RESULTS

Confocal and specular microscopy confirmed permanent endothelial cell loss with morphologic alteration after intracorneal penetration of ushaar latex. Corneal edema resolved completely after 2 weeks, although reduced endothelial cell count and abnormal morphology persisted.

CONCLUSION

Ushaar latex is capable of penetrating the corneal stroma and inducing permanent loss of endothelial cells. Corneal edema resolves if sufficient endothelial cell viability is still present after resolution of ushaar keratitis.

Natural rubber latex allergens: new developments

PURPOSE OF REVIEW

New allergenic latex proteins have been identified, whereas further information on known latex allergens has emerged in recent years. Although prevalence figures for sensitization to the various latex allergens have been published in several studies in the past, the data have not been collated to facilitate cross-comparison.

RECENT FINDINGS

Salient characteristics of the three most recently identified latex allergens, Hev b 11, 12 and 13 are described, whereas new findings on some of the previously recognized allergens are examined. Hev b 2 is viewed from the standpoint of allergenicity and protein glycosylation, Hev b 4 in relation to its biochemical identity and molecular cloning, Hev b 5 with respect to its recombinant form, and Hev b 6 in connection with conformational IgE epitopes. Reports on sensitization or allergic reaction to purified latex allergens from recent and past work are summarized. The use of latex allergens in latex allergy diagnostics is reviewed and discussed.

SUMMARY

Thirteen latex allergens have been recognized by the International Union of Immunological Societies. Based on the results of published studies, native Hev b 2, recombinant Hev b 5, native or recombinant Hev b 6, native Hev b 13, and possibly native Hev b 4 are the major allergens relevant to latex-sensitized adults. Although there is an increasing tendency to identify and characterize latex allergens largely on the basis of their recombinant forms, not all such recombinant proteins have been fully validated against their native counterparts with respect to clinical significance.

Hev b 5 and Hev b 13 as allergen markers to estimate the allergenic potency of latex gloves☆

BACKGROUND

Sensitization to natural rubber latex has been linked to proteins from medical latex gloves. Various assays to estimate the amount of residual allergenic proteins extractable from latex gloves to assess their potential exposure hazard have inherent weaknesses.

OBJECTIVE

This investigation was aimed at developing 2-site immunoenzymetric assays and identifying appropriate protein markers to assess the allergenic potential of latex gloves.

METHODS

The presence of 6 latex allergens--Hev b 1, 2, 3, 5, 6, and 13--was measured in a cross-section of commercial latex medical gloves by using monoclonal and polyclonal antibody-based 2-site immunoenzymetric assays. The overall allergenic potential of these gloves was assessed by IgE-inhibition assay. Stepwise multiple regression analyses were performed to identify marker allergens that best explained the variation in latex glove allergenicity.

RESULTS

All 6 latex allergens were detected in at least some of the glove samples. Hev b 5 and Hev b 13 were identified as the marker allergens that combined best to explain the variation in the glove allergenicity. The significant multiple correlation (R=0.855) between these 2 markers and glove allergenic potency forms the basis of an assay to gauge latex glove allergenicity.

CONCLUSION

The overall allergenic potential of latex gloves can be estimated by using Hev b 5 and Hev b 13 as indicator allergens. The correlation between glove allergenicity and the level of these allergens was maintained for low-protein gloves (<200 microg/g). This estimation of glove allergenicity was superior to that obtained by using total protein readings.