Hymenoptera venom allergy in outdoor workers: Occupational exposure, clinical features and effects of allergen immunotherapy.

OBJECTIVES: To describe (i) the clinical characteristics of workers, exposed to hymenoptera stings, with an ascertained diagnosis of Hymenoptera Venom Allergy (HVA), (ii) the specific role of occupational exposure, (iii) the effect of Venom Immunotherapy (VIT) in reducing the severity of allergic episodes in workers exposed to repeated stings of hymenoptera, and (iv) the management of the occupational consequences caused by allergic reactions due to hymenoptera stings. METHODS: Between 2000 and 2013 an observational study, including patients referred to the regional reference hospital of Liguria, Italy, with an ascertained diagnosis of HVA and treated with VIT, was performed. A structured questionnaire was administered to all patients to investigate the occupational features of allergic reactions. These were graded according to standard systems in patients at the first episode, and after re-stings, during VIT. RESULTS: One-hundred and 8four out of the 202 patients referred had a complete data set. In 32 (17.4%) patients, the allergic reaction occurred during work activities performed outdoor. Of these, 31.2% previously stung by hymenoptera at work, and receiving VIT, were re-stung during occupational activity. The grades of reaction developed under VIT treatment resulted clinically less severe than of those occurred at the first sting (p-value = 0.031). CONCLUSION: Our findings confirmed the clinical relevance of HVA, and described its occupational features in outdoor workers with sensitization, stressing the importance of an early identification and proper management of the professional categories recognized at high risk of hymenoptera stings. The Occupational Physician should be supported by other specialists to recommend appropriate diagnostic procedures and the prescription of VIT, which resulted an effective treatment for the prevention of episodes of severe reactions in workers with a proven HVA.

Birch allergy and oral allergy syndrome: The practical relevance of serum immunoglobulin E to Bet v 1.

BACKGROUND: Birch allergy (BA) may frequently be associated with fruit-vegetables oral allergy syndrome (OAS). Bet v 1 is the major birch allergen. Previously, it was reported that serum-specific immunoglobulin E (IgE) level could differentiate allergy from sensitization. Thus, this study aimed to investigate the practical role of Bet v 1 IgE. METHODS: A total of 245 subjects (128 women, 117 men; mean age, 41 years) with suspected allergic rhinitis and sensitization to Bet v 1 were evaluated. Serum IgE to Bet v 1 was assessed by using immuno-enzymatic. BA and OAS were diagnosed according to validated criteria. Symptom severity perception was measured by the visual analog scale. RESULTS: A total of 158 patients (64.5%) had BA. Patients with BA had higher serum Bet v 1 IgE levels than subjects who were sensitized (p < 0.0001). A cutoff value of 8.94 kUA/L predicted BA (area under the curve, 0.76; odds ratio, 6.18). Fifty-three patients with BA (33.5%) had OAS. Patients positive for OAS had higher Bet v 1 levels (p < 0.0001) and more-severe symptoms (p < 0.0001) than patients with BA and negative for OAS. A cutoff value of 17.4 kUA/L predicted OAS (area under the curve, 0.59; odds ratio, 3.19). CONCLUSIONS: The present study demonstrated that serum IgE levels to Bet v 1 could be a useful marker for differentiating between different birch pollen sensitization phenotypes.

Can serum white birch (Betula verrucosa) pollen antigen (Bet v 1) immunoglobulin E measurement distinguish between sensitization and allergy?

BACKGROUND: In clinical practice, it is fundamental to distinguish between sensitization and allergy, mainly with respect to polysensitized patients. The aim of this study was to evaluate whether serum immunoglobulin E (IgE) to white birch (Betula verrucosa) pollen antigen (Bet v 1) assessment might be able to differentiate simple sensitization from true allergy. METHODS: In total, 197 subjects (100 females; mean age 44.9 years) with serum Bet v 1 IgE positivity and history of nasal symptoms were evaluated. Subjects were subdivided in 2 groups: allergic and sensitized. RESULTS: Allergic patients were 58.4% of the total; they had higher serum Bet v 1 IgE levels than sensitized subjects (p < 0.001). A serum IgE to Bet v 1 value >8.94 kilo units of allergen per liter (kUA/L) was able to differentiate between sensitization and allergy (area under the receiver operating characteristic curve [AUC] = 0.76; diagnostic odds ratio, ie, degree of agreement between health status and dichotomized IgE levels [DOR] = 6.5). Gender and season when the blood was drawn influenced IgE levels. CONCLUSION: Serum Bet v 1 IgE measurement may be able to differentiate sensitization from allergy in subjects with sensitization to Betulaceae pollen allergens. Thus, Bet v 1 IgE measurement should be considered a useful step in the management of patients with allergic rhinitis due to Betulaceae pollen allergens.

Effectiveness of high dose sublingual immunotherapy to induce a stepdown of seasonal asthma: a pilot study.

BACKGROUND: There is ample evidence to support the efficacy of sublingual immunotherapy (SLIT) on allergic rhinitis, while there is less solid data regarding asthma. We evaluated the effects of a high dose birch SLIT on birch-induced rhinitis and asthma in a controlled study. METHODS: This double-blind, placebo-controlled, randomised, single centre trial on SLIT with birch pollen allergen extract (Stallergenes, Antony, France) included 24 patients presenting severe rhinitis and slight to moderate asthma, 14 actively and 10 placebo treated. SLIT was performed by a pre-coseasonal protocol, and was repeated for 2 years. The study plan included a selection visit, a visit at the start of the first and the second treatment cycle, a follow-up visit after 1-3 months from the start of each cycle, and a final visit at the end of each yearly cycle. RESULTS: A significant decrease (p < 0.05) in rhinorrhoea and nasal obstruction occurred in actively treated patients. The median number of days with asthma at visit 3 was 10 (0-27) in the active (SLIT) group and 13 (0-29) in the placebo group. The median number of days with asthma at visit 6 was 2 (0-6) in the SLIT group and 7 (0-15) in the placebo group (p < 0.05 between groups). A stepdown of asthma occurred in 77% of actively treated vs. none of placebo treated patients (p = 0.05). No severe adverse events were observed. CONCLUSIONS: This pilot study suggests that SLIT with high dose birch extract may be able to step down seasonal pollen-induced asthma after prolonged treatment.