Rabbit allergens: a significant risk for allergic sensitization in subjects without occupational exposure

BACKGROUND

Although rabbits are becoming popular as pets, data about the characteristics of allergic sensitization to rabbit allergens in patients without professional exposure are scarce.

AIMS OF THE STUDY

To determine the characteristics of allergic sensitization to pet rabbits, and the role of direct and indirect exposure to rabbits and rabbit allergens in non-professionally exposed patients.

METHODS

From among 1124 consecutive outpatients, we selected all subjects with an immediate skin reaction to rabbit dander. A clinical history including a careful evaluation of the modality of rabbit exposure, the results of skin-prick tests (SPTs) and total/specific IgE antibodies were recorded. The prevalence of rabbit ownership in the Naples area was also calculated.

RESULTS

Among 753 SPT-positive patients, 20 (2.65%) were sensitized to rabbit dander (5 patients were mono-sensitized). Fifteen patients reported direct rabbit contact (7 were rabbit owners and 8 had occasional contact outside the home); 3 patients had indirect exposure through contact with rabbit owners and 2 patients denied any direct or indirect exposure. Rabbit mono-sensitized owners of pet rabbits had persistent (moderate-severe) symptoms. The prevalence of rabbit ownership is 1.56%.

CONCLUSIONS

In susceptible not professionally exposed individuals, direct rabbit contact and, in some cases, indirect or no apparent exposure, may induce allergic sensitization to rabbit allergens. A progressive increase in rabbit sensitization (also by indirect exposure) may be expected as a consequence of the increase in rabbit ownership.

Working towards healthy air in dwellings in Europe

Poor indoor air quality has been implicated in the increase in allergic and respiratory diseases seen in industrialized countries in recent decades. Although air pollution in the workplace is well studied, much less is known about the consequences of poor air quality in homes. In an attempt to halt or slow down the increase in allergic and respiratory diseases, the European Federation of Allergy and Airways Diseases Patients Associations (EFA) carried out the EU-funded project entitled 'Towards Healthy Air in Dwellings in Europe' (THADE). The aims were to: compile an overview of evidence-based data about exposure to indoor air pollution and its health effects, particularly in relation to allergies, asthma and other respiratory diseases such as chronic obstructive pulmonary disease; review cost-effective measures and technology to improve indoor air quality; review legislation and guidelines on indoor air pollution; produce maps of pollutants in dwellings; and recommend an integrated strategy that defines appropriate indoor air quality policies for implementation in Europe. This paper summarizes the information about air quality in dwellings and indoor environment-related diseases collected by expert consultants within the framework of THADE and terminates with recommendations for actions aimed at improving air quality in homes. The results of this project confirmed that air pollution in dwellings is a relevant health problem. It is a complex problem that must be addressed at European and international levels, and it involves the medical profession, scientific societies, patients' organizations, lawmakers, architects and the building industry. The complete THADE report is available at http://www.efanet.org/activities/documents/THADEReport.pdf.

Severe systemic allergic reaction induced by accidental skin contact with cow milk in a 16-year-old boy. A case report

The symptoms of food allergy are rarely induced by skin contact. A 16-year-old boy was referred to our Allergology Centre after an episode of systemic symptoms triggered by accidental skin contact with a drop of cow milk (CM) dripped from a sandwich containing fresh cheese. The patient had been allergic to CM from the age of 24 months and had experienced several episodes of urticaria-angioedema after the ingestion of tiny or "hidden" amounts of CM proteins. In vivo and in vitro diagnostic procedures showed intense sensitisation to all CM proteins (1/100 dilutions of allergenic extracts produced large wheals, and class 4 specific IgE antibodies. Total IgE antibodies were elevate (770.0 UI/). A moderate degree of bronchial hyperresponsiveness was found (PC20 metacholine: 3.90 milligrams). This case report suggests that patients with a high degree of sensitisation to CM proteins should be alert to the danger of skin contact and should beware of "hidden" CM allergens.

Mechanisms and characteristics of airway sensitization to indoor allergens

The increasing prevalence of allergic respiratory diseases, and particularly of bronchial asthma, has been linked to changes induced by human activities in outdoor and indoor environments. People living in industrialized countries spend most of their time indoors: in private homes, offices and means of transport. Indoor environments are not a refuge from outdoor air pollution. Modern systems for energy saving such as insulated windows and doors reduce the indoor natural ventilation and consequently increase the rate of indoor humidity. These conditions may determine an increase in the level of indoor pollutants (tobacco smoke, gases produced by cooling processes etc.) and of allergens derived from mites, domestic animals and cockroaches. Upholstered furniture, wall-to-wall carpets, central heating systems and/or humidifiers may also contribute to the growth of mite populations. The increasing levels of exposure to pollutants and allergens in indoor environments represents a risk factor for the development of airway sensitization, especially if these materials are inhaled early in life. The major cat allergen Fel d 1 is considered an ubiquitous allergen, since it has been found in many indoor environments where a cat has never been kept. The clothing of cat owners seems to help spread Fel d 1 in cat-free environments. Sensitization to cockroach allergens is very common in patients living in urban areas where unhygenic conditions may favour the growth of cockroach populations. Monitoring of the levels of allergens and strategies of allergen and pollutant avoidance in indoor environments are the main ways to reduce the prevalence of respiratory allergies induced by these materials.

Report: Fifteenth General Meeting of The National Council Held in Bloemfontein on 1 and 2 July 1983

No abstract available