Sensitization to fungal allergens: Resolved and unresolved issues

Exposure and sensitization to fungal allergens can promote the development and worsening of allergic diseases. Although numerous species of fungi have been associated with allergic diseases in the literature, the significance of fungi from the genera Alternaria, Cladosporium, Penicillium, Aspergillus, and Malassezia has been well documented. However, it should be emphasized that the contribution of different fungal allergens to allergic diseases is not identical, but species-specific. Alternaria and Cladosporium species are considered to be important outdoor allergens, and sensitization and exposure to species of these genera is related to the development of asthma and rhinitis, as well as epidemics of asthma exacerbation, including life-threatening asthma exacerbation. In contrast, xerophilic species of Penicillium and Aspergillus, excluding Aspergillus fumigatus, are implicated in allergic diseases as indoor allergens. A. fumigatus has a high capacity to colonize the bronchial tract of asthmatic patients, causing severe persistent asthma and low lung function, and sometimes leading to allergic bronchopulmonary aspergillosis. Malassezia are common commensals of healthy skin, although they are also associated with atopic dermatitis, especially on the head and neck, but not with respiratory allergies. Despite its importance in the management of allergic diseases, precise recognition of species-specific IgE sensitization to fungal allergens is often challenging because the majority of fungal extracts exhibit broad cross-reactivity with taxonomically unrelated fungi. Recent progress in gene technology has contributed to the identification of specific and cross-reactive allergen components from different fungal sources. However, data demonstrating the clinical relevance of IgE reactivity to these allergen components are still insufficient

Serological diagnosis of allergic bronchopulmonary mycosis: Progress and challenges

Prompt diagnosis of allergic bronchopulmonary mycosis (ABPM) is an important clinical issue in preventing irreversible lung damage. Therefore, a good serological marker for the diagnosis of ABPM is desired in clinical practice. The measurement of IgE antibody to crude Aspergillus fumigatus allergen is considered the first step in screening asthmatic patients for allergic bronchopulmonary aspergillosis (ABPA). However, presence of IgE to A. fumigatus does not always indicate genuine sensitization to A. fumigatus because of cross-reactivity between crude extracts from different fungal sources. The application of molecular-based allergy diagnosis can solve this problem. The specificity of testing can be greatly improved by measuring the IgE antibody to Asp f 1 and f 2, specific allergen components for genuine A. fumigatus allergy. The problem of cross-reactivity between crude fungal extracts is also true for the identification of genuine causal fungi in each ABPM patient. Some patients with ABPM induced by fungi other than Aspergillus may be consistent with ABPA diagnostic criteria because current criteria depend on IgE/IgG reactivity to crude extracts. Accurate identification of genuine causal fungi for ABPM is of clinical importance, considering that clinical presentation, anti-fungal treatment strategies and disease prognosis can be influenced by different causal fungi. The diagnosis of causal fungi can be robustly validated by the confirmation of genuine sensitization to fungi after measuring IgE to specific allergen components, as well as repeated microbiological isolation of the fungi from their airway

Hand eczema as a risk factor for food allergy among occupational kitchen workers

Background: An increasing number of studies in children is highlighting the importance of transdermal routes of exposure to food allergens through damaged skin in the pathogenesis of food allergies. However, data on this in adults are limited. A few case-series studies has documented development of food allergy among kitchen workers with hand eczema after direct contact exposure to foods. Methods: To explore the significance of hand eczema as a risk factor for food allergies in adults at the epidemiological level, we performed a cross-sectional web-based questionnaire survey on kitchen workers whose exposures were classed as occupational (cooks and food handlers, n = 1592) or non-occupational (housewives, n = 1915). Logistic regression was used to explore the association between the presence/severity of hand eczema and the risk of food allergy after adjustment for potential confounders. Results: Current hand eczema and current diagnosed food allergy were more common among occupational kitchen workers (OKW) than among non-occupational kitchen workers (NOKW) (32.3%-vs-29.9% and 9.9%-vs-3.8%, respectively). Current hand eczema was significantly associated with increased risk of current diagnosed food allergy in OKW (adjusted odds ratio 2.4, 95% CI 1.6–3.7). Those with more severe hand eczema were more likely to suffer from allergic symptoms for foods, and diagnosed food allergy. Conclusions: This study illustrates a significant public health problem in the adult population, documenting a major impact of hand eczema on the ongoing adult food allergy epidemic. Keywords: Food allergy, Hand eczema, Kitchen worker, Occupational allergy, Sensitizatio