A. M. Vermeulen

Occupational allergy caused by flowers

We describe 14 consecutive patients with complaints due to the handling of flowers. The symptoms varied from allergic rhinoconjunctivitis and asthma to urticaria. Most patients had professions in the flower industry. Skin prick tests (SPT) were performed with home‐made pollen extracts from 17 different flowers known to be the most commonly grown and sold in The Netherlands. RAST against mugwort, chrysanthemum, and solidago was performed. The diagnosis of atopy against flowers was based on work‐related symptoms due to the handling of flowers, positive SPT with flower extracts, and positive RAST The concordance between SPT and case history was 74%, and that between SPT and RAST was 77% Extensive crosssensitization was seen to pollen of several members of the Compositae family (e.g., Matricaria. chrysanthemum, solidago) and to pollen of the Amaryllidaceae family (Alstroemeria and Narcissus). Homemade flower extracts can be used to confirm IgE‐mediated flower allergy. Mugwort can be used as a screening test for possible flower allergy. For most patients, the allergy led to a change of profession.

Prevalence of occupational allergy to bell pepper pollen in greenhouses in the Netherlands

Background An increasing number of allergic complaints appear to have occurred among bell pepper greenhouse employees.

Prevalence of sensitization to the predatory mite Amblyseius cucumeris as a new occupational allergen in horticulture

Background: Protection against thrips, a common pest in bell pepper horticulture is effectively possible without pesticides by using the commercially available predatory mite Amblyzeius cucumeris (Ac). The prevalence of sensitization to Ac among exposed greenhouse employees and its clinical relevance was studied.

Allergen-induced matrix metalloproteinase-9 in nasal lavage fluid

reactions to food allergens derived from banana, kiwi, and chestnut. Absolute values of IgE to latex showed no signi®cant alterations except at the end of the study, when an increase of approximately 4±6 URAST/ml was seen. However, IgE speci®c for chestnut clearly decreased during treatment from 0.72 to 0.30 kU/l). The behavior of IgG class speci®c for latex was similar to that of speci®c IgE. We did not detect latex-speci®c IgG4 during the study; however, this immunoglobulin apparently began to appear at the end of the study. Clinical symptoms improved steadily, with an evident reduction in nasal obstruction and eye manifestations. This was corroborated by the patient, who reported improvement even in areas of the hospital that produced signi®cant exposure to latex gloves, which she had previously been unable to tolerate. Acquisition of tolerance to the environment in her workplace was gradual during SIT, but was more pronounced once the maintenance period was started upon her discharge from the hospital and return to work. Because of the occupational nature of the allergy, the best provocation test for the allergen was constant exposure to latex in the workplace. However, we also used speci®c, controlled provocation tests. The patient entered a 1-m airtight cabin and handled four pairs of latex gloves for 15 min; her clinical symptoms were then evaluated during the 6 h following this exposure to the allergen. Clinical examination after the provocation test showed that she had no cutaneous, eye, nasal, or bronchial symptoms during the following 6 h. In terms of local reactions, tolerance of SIT was excellent, with no delayed local reactions and only one episode of immediate local reaction during the maintenance phase (erythema with papules measuring 60 mm in mean diameter). This reaction did not require treatment or a change in the desensitization schedule. We believe that the allergenic extract is safe, at least at concentrations up to 0.4 mg latex protein. Tolerance was excellent, and, like other authors who used accelerated schedules (6), we established the MD on the basis of the appearance of a systemic reaction. We felt this to be the most prudent approach, in contrast to other studies in which the appearance of a systemic reaction led only to a change in the dose schedule (7, 8). Use of a conventional schedule would probably have allowed us to reach a higher MD, a possibility that deserves further study. We consider SIT with latex to be highly effective, and found the allergenic extract used to be safe and well tolerated.

Prevalence of natural rubber latex allergy (Type I and Type IV) in laboratory workers in The Netherlands

The objective of the study was to study the prevalence of Type IV and Type I allergy to natural rubber latex (NRL) in a population at risk in the Netherlands. Laboratory workers regularly using gloves were invited to complete a questionnaire and to be tested. We performed patch tests with standard contact allergens, rubber additives, glove powder and pieces of 4 gloves; prick tests with inhalant allergens, glove extracts, glove powder and fruit extracts; and RASTs. Glove‐related hand dermatitis was reported in 36.9% of the individuals interviewed. A positive patch test result for rubber additives was seen in only 6.6%. Glove‐related urticaria, rhinoconjunctivitis and/or asthma were reported in 24.6% of all cases. Confirmation of an IgE‐mediated reaction was achieved in 8.3% by prick test with glove extracts and 5.0% by RAST No reaction to glove powder was noticed in patch testing or in prick testing. A high prevalence rate of glove‐related symptoms and NRL Type I allergy was found in laboratory workers exposed to rubber gloves. Surprisingly, there was no co‐existence of Type I and Type IV allergy in this population.

Immunoblot Analysis of IgE-Binding Antigens in Paprika and Tomato Pollen

Background: The high incidence of occupational allergy in horticulture has only recently been recognized. We determined IgE against pollen and fruit from paprika and tomato plants in sera from 3 greenhouse workers and in 3 sera from food-allergic patients. Methods: Proteins in extracts of paprika and tomato pollen were incubated with patients’ sera after covalent coupling of these proteins to agarose beads, or in immunoblots. Results: IgE against paprika pollen, but no IgE against tomato pollen, was found in serum from 2 greenhouse workers who worked with paprika plants only. IgE binding of these 2 sera to agarose-bound paprika pollen extract could be inhibited by paprika pollen but not by tomato pollen extract. A greenhouse worker, who cultivated tomato plants, had IgE against both tomato and paprika pollen. IgE binding of this serum to agarose-bound paprika pollen extract could be inhibited by both paprika pollen and tomato pollen extract. Three food-allergic patients also had IgE against tomato and paprika pollen. IgE from 2 food-allergic patients recognized IgE-binding structures in paprika or tomato pollen that were also present in fruit from the corresponding plant. In contrast, no substantial cross-reactivity was observed between paprika pollen and fruit towards IgE from 3 greenhouse workers. In 4 of 5 sera that were positive in the paprika pollen immunoblot major IgE binding to allergens of about 30 and 64 kD occurred. Conclusion: The presence of IgE against paprika or tomato pollen is not restricted to workers in horticulture; IgE against these pollen can also be present in food-allergic patients who have serum IgE against paprika and/or tomato fruit.

Allergy to bumblebee venom. III. Immunotherapy follow‐up study (safety and efficacy) in patients with occupational bumblebee‐venom anaphylaxis

Background: The objective was to investigate whether venom immunotherapy with bumblebee venom (BBV) is safe and effective.

Primary sensitization to sweet bell pepper pollen in greenhouse workers with occupational allergy

Background In a previous investigation, a high prevalence of allergy to sweet bell pepper pollen was found among exposed horticulture workers. Allergy to plant‐derived food is often the consequence of primary sensitization to common pollen allergens.

Histamine release from human peripheral blood leukocytes analyzed by histamine radioimmunoassay.

Histamine release from human peripheral blood leukocytes, afterin vitro challenge with allergen extracts, is usually measured by fluorometry. In the present study we compared the results of the automated fluorometric histamine assay (Siraganian) with those of the Immunotech histamine radioimmunoassay. Histamine release dose — response curves obtained after histamine measurement by both methods were superimposable.

Occupational asthma to amaryllis

N GREENHOUSE workers, various decorative I flowers may cause occupational airway disease through an IgE-dependent mechanism. Immediatetype allergy has been documented to freesia, chrysanthemum, weeping fig, statis, and Lathyrus odoratus ( 1-6). We describe a greenhouse worker who developed an IgE-mediated allergy to hippeastrum (genus Hippeastrum, family Amaryllidaceae). Hybrid cultivars are mostly known as amaryllis. One year after beginning to work in a greenhouse where amaryllis plants were cultivated, a 50-yearold man developed