This Month's Feature Review:

Plant Allergies

There are thousands of plant species that can produce skin reactions. Plants can produce several types of skin reaction including:
" Irritant contact dermatitis
" Allergic contact dermatitis
" Photodermatitis
" Contact Urticaria

Allergic Contact Dermatitis (ACD) due to plants

This is the phytodermatitis causing the most trouble.
In the case of a florist, gardener, or forester thinking of the possibility of plant ACD is quite easy, but for the housewife reacting to indoor plants like primula (primrose) this diagnosis is often overlooked. Factors making plant dermatitis likely include:
" Exposed skin affected
" Spring/summer flare
" Hand or facial dermatitis

Occupational or hobby-related exposure to plants...
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Ethanol as a cause of hypersensitivity reactions to alcoholic beverages

Ehlers, U.-C. Hipler et al Dept. Derm. and Allergy Humboldt-University, Berlin

Background: Adverse reactions after ingestion of alcoholic beverages are common. Metabolic differences in individuals and also the histamine content in alcohol beverages have been implicated. By contrast pure ethanol has rarely been reported as a cause of hypersensitivity reactions and its mechanisms have not been clarified yet.

Objective: To determine whether ethanol itself accounts for alcohol hypersensitivity in patients with anaphylactic reactions after alcohol intake. In search of possible pathomechanisms all patients were analyzed by skin prick testing and sulfidoleukotriene production of peripheral leukocytes using ethanol and its metabolites.

Methods: Double-blind, placebo-controlled food challenges with a cumulated amount of 30ml ethanol were performed in 12 adult patients with a positive history of adverse reactions after consumption of different alcoholic beverages. Skin prick tests and measurement of sulfidoleukotriene production were performed using different concentrations of ethanol and acetaldehyde from 50 to 1000ml.

Results: Oral challenges with pure ethanol were positive in 6 out of 11 patients. All challenge-positive patients, but also four out of five challenge-negative patients showed an increased sulfidoleukotriene production in-vitro compared with healthy controls. Skin prick tests using alcoholic beverages, ethanol, acetaldehyde, and acetic acid were negative in all patients (12/12).

Conclusions: Our study shows that ethanol itself is a common causative factor in hypersensitivity reactions to alcoholic beverages. These reactions occur dose-dependent and a non-IgE-mediated pathomechanism is likely, because skin prick tests were negative in all cases. Increased sulfidoleukotriene production was determined in some patients, but is no reliable predictor. Therefore, oral provocation tests remain indispensable in making the diagnosis of ethanol hypersensitivity.

Reference: Clinical & Experimental Allergy, August 2002; Vol 32: Number 8

Clinical characteristics of patients with mustard hypersensitivity.

Caballero T, San-Martin MS, Padial MA, Contreras J, Cabanas R, Barranco P, Lopez-Serrano MC

Seccion de Alergia, Hospital Universitario La Paz, Madrid, Spain. mcm01m@inicia.es

Background: Although mustard is frequently consumed in Spain and elsewhere, only isolated case reports of mustard allergy have been reported. No large series of case studies have been published.

Objectives: We sought to describe demographic, clinical, and immunologic characteristics of patients with mustard hypersensitivity and to determine whether any significant differences exist in age, gender, atopic family history, total immunoglobulin E (IgE) level, and specific IgE to mustard ratio among patients with differing characteristics.

Methods: Twenty-nine patients with a history of mustard allergy underwent skin prick tests with mustard, determination of total IgE, and evaluation of specific IgE to mustard. Skin prick tests with Lolium perenne, Olea europaea, and Artemisia vulgaris were done in patients with symptoms of pollinosis. The aforementioned variables were compared between various subgroups of patients for systemic versus local reactions to mustard, association versus no association with allergies to other vegetable foods, and association versus no association with pollinosis.

Results: The male: female ratio was 10:19. Skin prick tests to mustard were positive in all patients. The total IgE geometric mean was 189.3 kU/L. The specific IgE to mustard was positive in all patients (0.7 to > 100 kU/L). Of the 29 patients, 19 (66%) had a systemic reaction after consumption of mustard, and 10 (34%) had a local reaction; 14 (48%) had anaphylaxis. Fifteen patients (52%) had symptoms after ingestion of other vegetable foods, and 15 also had typical symptoms of pollinosis. No significant differences were found in age, sex, atopic family history, total IgE, and specific IgE to mustard between the various subgroups studied. Conclusions: Most study patients with mustard hypersensitivity had a systemic reaction and had associated pollinosis or allergy to other vegetable foods. Mustard sensitivity should be routinely tested in patients with idiopathic anaphylaxis.

Reference: Ann Allergy Asthma Immunol 2002 Aug; 89(2): 166-71

Cross-reactivity between raw mushroom and molds in a patient with oral allergy syndrome

Dauby PA, Whisman BA, Hagan L.,

Department of Allergy and Immunology, Wilford Hall Medical Center, Lackland Air Force Base, Texas, USA. Pdauby@pol.net

Background: Oral allergy syndrome, resulting from cross-reactivity between raw fruits and vegetables and a number of pollens, is well described. However, it has never been associated with mold spore sensitivity and mushrooms. We evaluated a patient with oral allergy symptoms to raw, but not cooked, mushrooms, which also had positive skin testing to molds.

Objective: To identify and characterize antigenic cross-reactivity between mushroom and mold spores.

Methods: The patient underwent skin prick testing to molds and mushroom. Proteins from raw and cooked mushrooms were extracted and immunoblot/inhibition assays were performed to evaluate for cross-reacting immunoglobulin E antibodies between mushroom and mold extracts to which the patient was sensitive.

Results: The patient had a positive skin prick test result to raw mushroom and four types of molds. The immunoblot assay revealed immunoglobulin E antibodies directed against similar molecular weight proteins in the raw mushroom and 3 of the 4 molds: Alternaria tenuis, Fusarium vasinfectum, and Hormodendrum cladosporioides. These protein bands on protein electrophoresis were absent in the cooked mushrooms. Inhibition immunoblot of the raw mushroom with the three molds indicated total inhibition of the 43- and 67-kD protein bands.

Conclusions: We report the first case of cross-reactivity between mushroom and molds in a patient with oral allergy syndrome to raw mushroom and allergic rhinitis secondary to molds.

Reference: Ann Allergy Asthma Immunol 2002 Sep; 89(3): 319-21

Sensitization to airborne moulds and severity of asthma: cross sectional study from European Community respiratory health survey

Zureik M, Neukirch C, Leynaert B, Liard R, Bousquet J, Neukirch F; European Community Respiratory Health Survey.

European Community Respiratory Health Survey, Unit 408 Epidemiologie, Faculte de Medecine Xavier Bichat, BP 416, 75870 Paris CEDEX 18, France. zureik@vjf.inserm.fr

Objective: To assess whether the severity of asthma is associated with sensitization to airborne moulds rather than to other seasonal or perennial allergens.

Design: Multicentre epidemiological survey in 30 centers.

Setting: European Community respiratory health survey.

Participants: 1132 adults aged 20-44 years with current asthma and with skin prick test results.

Main outcome measures: Severity of asthma according to score based on forced expiratory volume in one second, number of asthma attacks, hospital admissions for breathing problems, and use of corticosteroids in past 12 months.

Results: The frequency of sensitization to moulds (Alternaria alternata or Cladosporium herbarum, or both) increased significantly with increasing asthma severity (odds ratio 2.34 (95% confidence interval 1.56 to 3.52) for either for severe v mild asthma). This association existed in all of the study areas (gathered into regions), although there were differences in the frequency of sensitization. There was no association between asthma severity and sensitization to pollens or cats. Sensitization to Dermatophagoides pteronyssinus was also positively associated with severity. In multivariable logistic regressions including sensitization to moulds, pollens, D pteronyssinus, and cats simultaneously, the odds ratios for sensitization to moulds were 1.48 (0.97 to 2.26) for moderate v mild asthma and 2.16 (1.37 to 3.35) for severe v mild asthma (P<0.001 for trend).

Conclusions: Sensitization to moulds is a powerful risk factor for severe asthma in adults. This should be taken into account in primary prevention, management, and patients' education.

Reference: BMJ 2002 Aug 24; 325(7361): 411-4