The dental management of patients with natural rubber latex allergy

PURPOSE: The use of highly purified follicle-stimulating hormone (Metrodin-HP) was compared with that of a preparation containing follicle-stimulating hormone and luteinizing hormone (Pergonal) for production of superovulation in an IVF program. METHODS: We used the Oxford Fertility Unit database to identify patients undergoing their first cycle of IVF, using either Metrodin-HP or Pergonal. Patients were treated with a standardized drug protocol and were stratified by age and cause of infertility. Ovarian stimulation with either Metrodin-HP (Serono Laboratories) or human menopausal gonadotropin (hMG; Pergonal; Serono Laboratories) after pituitary desensitization commenced in the midluteal phase of the preceding cycle. Monitoring was performed by ultrasound and serum estradiol measurement prior to transvaginal oocyte recovery, followed by IVF and transfer of no more than three embryos. RESULTS: For Metrodin-HP versus Pergonal, the rates of egg retrieval (98 vs 94%), fertilization (89 vs 92%), clinical pregnancy (32.9 vs 23.4%), miscarriage (4.1 vs 4.5%), live birth (26 vs 18.5%), and ovarian hyperstimulation syndrome (5.5% vs 5.9%) were similar in both groups. The apparent increase in clinical pregnancy and live birth with Metrodin-HP did not reach statistical significance. The dosages of gonadotropins used were comparable. Estradiol levels measured on day 8 of stimulation were significantly lower in the Metrodin-HP group than in the Pergonal group, but the difference did not reach statistical significance on the day of hCG administration. Significantly more follicles (greater than 12 mm) were obtained in the Metrodin-HP group, but the numbers of eggs recovered and fertilized were similar in the two groups. CONCLUSIONS: These findings demonstrate that highly purified FSH (Metrodin-HP) is as effective and successful as hMG (Pergonal) for ovarian stimulation in a standard IVF regimen. Exogenous luteinizing hormone (LH) is not required for satisfactory ovarian stimulation in IVF. Measurement of estradiol may be less helpful in the monitoring of Metrodin-HP cycles, but the level reached on the day of hCG administration can still be used to predict, and hence avoid, ovarian hyperstimulation syndrome.     

Diagnosis of natural rubber latex allergy: multicenter latex skin testing efficacy study. Multicenter Latex Skin Testing Study Task Force

BACKGROUND: No characterized diagnostic natural rubber latex skin testing material is licensed for use in the United States. OBJECTIVE: We have conducted a multicenter clinical skin testing study to document the safety and diagnostic sensitivity and specificity of a candidate Hevea brasiliensis nonammoniated latex (NAL) extract. These data are intended to support the licensing of this reagent for the diagnosis of latex allergy in high-risk populations. METHODS: Three hundred twenty-four subjects (304 adults and 20 children) were classified by their clinical history as having latex allergy (LA group, 124 adults and 10 children) or having no latex allergy (NLA group, 180 adults and 10 children). All subjects provided blood samples and then received sequential puncture skin tests (PSTs) at 1, 100, or 1000 microg/mL protein with a bifurcated needle and NAL (Greer Laboratories) from Malaysian Hevea brasiliensis (clone 600) sap. A 2-stage glove provocation test was used to clarify latex allergy status of individuals with positive history/negative PST result and negative history/positive PST result mismatches. RESULTS: Twenty-four subjects (15%) originally designated as having LA on the basis of their initial clinical history were reclassified to the NLA group on the basis of a negative glove provocation test result. Of the 134 subjects with LA, 54 (40%) were highly sensitive to latex, with a positive PST result at 1 microg/mL NAL. The Greer NAL reagent produced a positive PST rate (sensitivity) of 95% and 99% in subjects with LA at 100 microg/mL and 1 mg/mL, respectively. The negative PST rate (specificity) in 190 subjects with a negative history with the NAL extract at 100 microg/mL and 1 mg/mL, was 100% and 96%, respectively. Immediately after the PST, mild systemic reactions (mainly pruritus) were recorded in 16.1 % of the adults in the LA group and 4.4% of the adults in the NLA group. No reactions required treatment with epinephrine. Only mild delayed reactions were observed in 9.6% (LA group) and 2.8% (NLA group) of subjects 24 to 48 hours after PST. Mean wheal and erythema diameters measured in the 10 children in the LA group with spina bifida at 100 microg/mL and 1 mg/mL were similar to those observed in the adults in the LA group, suggesting that children are not at increased risk for systemic reactions compared with adults. CONCLUSIONS: A suggestive clinical history is necessary but not sufficient for a definitive diagnosis of IgE-dependent latex allergy. These data support the safety and diagnostic efficacy of the Greer NAL, skin test reagent at 100 micro/mL and 1 mg/mL for confirmatory PSTs.     

Cross-reacting allergens in natural rubber latex and avocado

Although phencyclidine (PCP) has several neurochemical effects, the most pharmacologically relevant are thought to be its ability to antagonize the activity of N-methyl-D-aspartate (NMDA)-type glutamate receptors and to increase extracellular dopamine concentrations. In order to elucidate the nature and consequence of PCP actions on glutamatergic and dopaminergic pathways, this study examined the response of extrapyramidal and limbic neurotensin systems to this drug. Multiple, but not single, doses of PCP caused increases in striatal neurotensin-like immunoreactivity content of 150-200% of control. These effects were blocked by the dopamine D1 receptor antagonist, SCH 23390, suggesting they were caused by PCP-mediated enhanced dopamine activity at dopamine D1 receptors. In contrast, MK-801 (dizocilpine), a selective NMDA receptor antagonist that acts at the same site as PCP, had no effect on neurotensin-like immunoreactivity content when given alone. In addition, coadministration of MK-801 with PCP did not alter the effect of PCP on striatal neurotensin-like immunoreactivity content. This lack of effect suggests that the actions of PCP on NMDA receptors was not involved in the neurotensin response. The PCP effect on neurotensin striatal pathways also appeared not to be associated with the dopamine D2 or gamma-aminobutyric acid (GABA) systems: a possible role for the sigma receptor in this effect could not be eliminated. Administration of multiple doses of PCP also affected neurotensin-like immunoreactivity content in the nucleus accumbens (160% compared to control) and frontal cortex (40% compared to control), but not the substantia nigra. The neurotensin effects of PCP are compared to those of another psychotomimetic drug of abuse, methamphetamine.     

Prospective study of risk factors in natural rubber latex hypersensitivity

Five hundred sixty-nine subjects routinely underwent skin prick tests for latent sensitization to latex. The study of risk factors included skin tests to inhalant allergens, to diagnose atopy, and a questionnaire aimed at revealing frequent exposure to latex such as the wearing of gloves, multiple surgical procedures, or urinary catheterization. The subjects were categorized into five groups: group I, subjects with no risk factor (n = 272); group II, nonatopic subjects exposed to latex (n = 73); group III, atopic subjects not exposed (n = 180); group IV, exposed atopic subjects (n = 44); and group V, subjects with a history of intraoperative anaphylactic shock caused by latex (n = 13). Twenty-five subjects had spina bifida and were in either group II (14 subjects) or group IV (11 subjects). The questionnaire identified a probable allergy to latex in 18 subjects: 16 cases were confirmed by skin test, but responses were not informative in 23 patients who were sensitive to latex. Positive prick tests to latex were obtained in 0.37% of group I, 6.85% of group II, 9.44% of group III, and 36.36% of group IV. Of the children with spina bifida, 32% had positive skin test results. As risk factors, atopy and exposure were synergistic. We recommend predictive prick tests not only in children with spina bifida but also in any atopic subject or in any patient with a history of frequent exposure to latex. Latex could be considered a habitual allergen. The use of latex urinary catheters should be avoided in patients who are catheterized on a daily basis.     

Understanding latex allergy

Latex allergy is an increasingly important problem in both health-care workers and patients. Predisposing factors to development of latex allergies include a history of atopy or allergy and frequent exposure to latex products. Identified allergens include latex proteins from the rubber tree that remain in manufactured products, as well as smaller molecules that remain from the latex purification and manufacturing process. Latex proteins absorbed to powder in latex surgical and examination gloves may be aerosolized and inhaled. Powder-absorbed latex proteins are thought to be important in triggering of sensitization in susceptible individuals, as well as in elicitation of symptoms in previously sensitized patients. Allergic reactions to latex can include local dermal reactions or generalized immediate hypersensitivity (anaphylactic) reactions. Pathophysiology, signs and symptoms, and treatment of each type of reaction are discussed. Measures to address latex allergy, however, must include measures to decrease exposure to latex antigens both in latex-allergic subjects, to prevent symptoms, and in naive subjects, to prevent sensitization. These measures may include finding, acceptable substitutes for latex in many products.     

Cross-reactivity between Ficus benjamina (weeping fig) and natural rubber latex

The efficacy of hydroxyzine and buspirone, controlled by placebo, was investigated in a double-blind, parallel group, multicentre study conducted in France and the UK. A total of 244 patients with generalised anxiety disorder in primary care was allocated randomly to treatments with hydroxyzine (12.5 mg morning and mid-day, 25 mg evening), buspirone (5 mg morning and mid-day, 10 mg evening) or placebo (three capsules/day) for 4 weeks, preceded by a 1-week single-blind placebo run-in and followed by 1-week single-blind placebo administration. Rating scales were applied on days -7,0,7,14, 12,28 and 35. Seventy percent of the patients were female, the average age was 41 +/- 11 years, and the mean Hamilton Anxiety Score at day 0 was 26.5 +/- 4.2. Only 31 of the 244 patients dropped out, but equally in the three groups. Intention-to-treat LOCF analyses on the primary variable showed a significant difference only between hydroxyzine and placebo with respect to improvement on the Hamilton Anxiety Scale (10.75 versus 7.23 points, respectively). Secondary variables such as CGI and self-ratings (HAD scale) showed both hydroxyzine and buspirone to be more efficacious than placebo. Thus, hydroxyzine is a useful treatment for GAD.     

Diagnostic criteria for latex allergy

The author has made an observation which seems to illustrate his proposition perfectly. A patient who was the victim of many acute episodes of rhino-conjunctivitis and severe Quincke's oedema has found benefit from two specialised assessments which established a diagnosis of allergy only to latex. The key to this diagnosis rested on unusual reasoning based on a search for a sufficiently "virulent" allergen to be responsible for the severity of the clinical signs. This idea and recent understanding of crossed allergy materials should aid detection of subjects who are allergic to natural latex.     

Update in allergy and immunology

Internal medicine has witnessed astounding developments in our understanding of the immune system's role in the pathophysiology of many diseases. The present challenge is to harness this knowledge to develop more effective therapies for immune-related illness. Guidelines for the care of common illnesses such as asthma may encourage appropriate clinical application of advances in our armamentarium against immune disease.     

Reinforcement of natural rubber latex with silica modified by cerium oxide: preparation and properties

Variable masses of nano cerium oxide(CeO__2) were added into nano silica(SiO__2) to prepare the well-dispersed SiO_2-CeO_2suspension(SiO_2-CeO_2), cetyltrimethyl ammonium bromide(CTAB) was used to adjust the compatibility of SiO_2-CeO_2 with rubber matrix, then SiO_2-CeO_2 modified by CTAB and curing formulas were mixed with fresh natural rubber(NR) latex to prepare NR/SiO_2-CeO_2 nanocomposites that contained 0–10 parts of CeO_2 by a new emulsion compounding method. The morphologies, cure characteristics, mechanical properties and thermal-oxidative stability of NR/SiO_2-CeO_2 nanocomposites were investigated. The results revealed that the presence of CeO_2 in NR/SiO_2-CeO_2 nanocomposites was favorable for enhancing the interaction between NR matrix and fillers, helped to get smaller SiO_2-CeO_2 particles with narrower particle size distribution, further improved the crosslink densities and mechanical properties of NR/SiO_2-CeO_2 nanocomposites vulcanizates. Meanwhile, the addition of CeO_2 increased the active energy at least 4.66%, obviously improved the thermal-oxidative aging-inhibiting properties of NR/SiO_2-CeO_2 nanocomposites. Additionally, nanocomposites containing CeO_2 promoted T g shift to high temperature direction, causing the nanocomposites featured higher tanδ at 0 oC and lower tanδ at 60 oC and exhibited comparable wet grip and lower rolling resistance when NR/SiO_2-CeO_2 nanocomposites were used in tire tread compound.     

Sensitivity to latex and other rubber substances--an important occupational risk for health personnel (case report)

Sensitization to latex and rubber additives has been acknowledged during the last 10 years as a major occupational health problem among health-care workers. In sensitized persons, respiratory and/or skin symptoms may be present. Pathophysiologic mechanisms of senzitisation involve allergic reactions types I and IV (Coombs and Gell). In this case report we described a female health-care worker with sensitization to latex and rubber additives simultaneously present on the skin and in the respiratory system, caused by wearing protective rubber gloves. The complex diagnostic procedure involved in determination of occupational allergic diseases is discussed.     

Rubber latex allergy and the endodontic patient

Increasingly, patients with rubber latex allergy are being seen in dental offices. Health care workers, persons allergic to certain foods and those with certain medical histories are potentially latex-sensitive. This article presents the case of a patient with a history of severe rubber latex allergy and the associated management of an endodontically involved tooth. The possibility of the latex allergic patient being sensitive to gutta-percha obturation material is also raised.     

Severe latex allergy: three first-person accounts

Glaucoma is a group of ocular disorders leading to reduced visual capabilities and sometimes blindness. The biochemical defect is unknown but it is shown that reduced drainage of the aqueous humour from the anterior chamber may lead to increased intraocular pressure and gradual atrophy of the optic neurons. Families with various forms of autosomal dominant (AD) glaucoma have been linked to 1q21-31, 2cen-q13, 4q25-27, and 13q14 and autosomal recessive congenital glaucoma have been localized to chromosome 1p36 and 2p21. Recently, a locus for AD iridogoniodysgenesis anomaly (IGDA) was mapped to chromosome 6p25. This study refines the localization of IGDA to an approximately 6-cM interval between D6S1600 and D6S1617/D6S1713 at 6p25-tel, based on recombinations in affected individuals with AD juvenile-onset glaucoma and concomitant iridogoniodysgenesis.     

Practitioner and student latex exposure and allergy

Greater application of universal precautions has increased practitioner exposure to chemicals present in personal protective equipment. Of prime concern is the latex present in examination and surgical gloves. A survey concerning latex exposure, allergies, and handwashing was administered to three advanced classes of dental students and was sent to 300 private practitioners in Central Indiana. Results indicate that adverse skin reactions to latex start while in dental school. Problems due to latex gloves were reported by 18.6 percent of the students. Student handwashing materials and methods were adequate, except for inadequate washing time. Adverse skin reactions were reported by 24.1 percent of practitioners wearing latex gloves. Two handwashing problems were noted--inadequate washing time and the common use of water instead of an antimicrobial soap after glove removal. Both students and practitioners reported relatively high levels of personal and family histories of allergy to a variety of sources.