Starch and natural rubber allergen interaction in the production of latex gloves: a hand-held aerosol

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.

Different latex aeroallergen size distributions between powdered surgical and examination gloves: significance for environmental avoidance

BACKGROUND

Proactive medical institutions implement latex allergen avoidance to protect workers and patients with latex allergy and to prevent latex sensitization in these groups by creating latex-safe environments that include replacement of natural rubber latex examination and surgical gloves, especially those that are powdered, with synthetic alternatives. We have hypothesized that an apparent decreasing trend in new latex allergy cases in hospitals using only synthetic examination gloves but the occasional powdered latex surgical glove might result from constitutive differences in allergen content (particle size distribution and quantity) between powdered surgical gloves and examination gloves.

OBJECTIVE

Because aerodynamic particle size determines where inhaled airborne allergen deposits in the airway, the aim of this study was to investigate the differential particle size distribution of latex allergen released from powdered latex examination and surgical gloves.

METHODS

Powdered and nonpowdered latex examination and surgical gloves were processed to create an aerosol in a glove box equipped with air sampling equipment capable of total particle number and mass measurements. Air particulate generated in the glove box was collected on impactors with less than 2.5-microm, 2.5- to 10-microm, and greater than 10-microm particle size limits (4 L/min for 4 hours). All filters were extracted, and latex allergen was quantified by using a latex-CAP inhibition assay with a human IgE anti-latex serum pool.

RESULTS

Latex aeroallergen on powdered sterile surgical gloves resided primarily on particles greater than 10 microm in size (P <.006). In contrast, powdered examination gloves released the highest total latex aeroallergen content, with 68% of the particles sized in the respirable 2.5- to 10-microm range and carrying 56% of the airborne latex allergen.

CONCLUSIONS

Significantly lower quantities and larger sizes of latex allergen-containing particles released from surgical gloves provides one potential explanation as to why an apparent decrease in new cases of latex allergy can occur in hospitals that successfully replace latex examination gloves with synthetic gloves but continue occasional use of powdered surgical gloves.

Latex allergy

Allergy to natural rubber latex affects people routinely exposed to rubber products. Groups thought to be at highest risk include atopics, health care workers, rubber industry workers, and individuals who have undergone multiple surgical procedures, especially those with spina bifida. Allergy to latex is a type I, immediate, IgE-mediated reaction that can lead to anaphylaxis and death. The prevalence, risk factors, clinical manifestations, diagnosis, and management of latex allergy are summarized in this review.

Quantified environmental challenge with absorbable dusting powder aerosol from natural rubber latex gloves

BACKGROUND

There are few data that link quantified natural rubber latex (NRL) absorbable dusting powder aerosol to biologic responses in NRL-sensitized subjects.

METHODS

We conducted a study on 30 health care workers with possible occupational asthma. All the subjects but 2 had a positive skin prick test result with NRL extract. Quantified environmental challenge (QEC) with powdered NRL gloves was performed in a 7-m(3) chamber. The patients would don and discard a pair of gloves every 3 minutes up to a maximum of 60 minutes. The concentrations of NRL aeroallergen were measured by a competitive IgE immunoassay. Ocular and respiratory symptoms and pulmonary function were monitored.

RESULTS

Twenty-six patients (87%) had rhinoconjunctivitis, 19 (63%) had an asthmatic response (responders), and 1 patient developed eosinophilic bronchitis on QEC. The asthmatic responses were of the early type in 15 patients, dual in 3, and isolated late in 1 patient. The duration of exposures sufficient to elicit asthmatic responses varied from 3 to 114 cumulative minutes. Time-weighted average NRL aeroallergen concentrations during QEC with responders ranged between 199 and 1107 ng/m(3). NRL concentrations measured at various time points during exposure were reproducible. Measured concentrations of NRL aeroallergen between responders (677 +/- 281 ng/m(3)) and nonresponders (611 +/- 351 ng/m(3)) were not statistically different. The cumulative inhaled NRL aeroallergen dose required for an asthmatic response ranged between 25 to 515 ng.

CONCLUSION

The total dose of latex aeroallergen eliciting an asthmatic response during QEC was mostly affected by the duration of exposure and varied widely from person to person.

Cotton fluffs as latex allergen carriers in a glove factory

BACKGROUND

Latex allergens released from gloves and bound to airborne cornstarch powder have been shown to cause respiratory allergy in health care workers.

OBJECTIVE

Cornstarch from powdered latex gloves is a well-known carrier of airborne allergens. It should be investigated whether cotton fluffs used to lubricate household and industrial gloves also function as airborne carriers for latex allergens.

METHODS

Latex gloves, cotton fluffs with or without latex glove contact, dipping water from the glove cooling tank, a dust sample from the floor, and 10 samples from area dust samplers were analyzed for their allergen content by using a CAP inhibition method. Furthermore, 84% (119/142) of the working group participated in a cross-sectional study involving a questionnaire and measurement of latex-specific IgE by means of CAP inhibition.

RESULTS

Latex gloves, area dust samples from latex glove production sites, and the floor dust sample contained high concentrations of latex allergens. Cotton fluffs were free of allergens before being in contact with gloves but showed considerable allergen concentrations after their removal from gloves. The dipping water of the cooling tank also contained latex allergens. Of the examined employees, 12.6% had IgE-mediated sensitization, and a third of the sensitized subjects (ie, 4% of the total group) reported work-related hypersensitivity reactions.

CONCLUSIONS

Cotton fluffs bind latex allergens and behave like cornstarch as airborne allergen carriers causing conjunctivitis and allergic respiratory disorders.