This pocket guide is the result of a consensus reached between members of the Global Allergy and Asthma European Network (GA(2) LEN) and Allergic Rhinitis and its Impact on Asthma (ARIA). The aim of the current pocket guide is to offer a comprehensive set of recommendations on the use of skin prick tests in allergic rhinitis-conjunctivitis and asthma in daily practice. This pocket guide is meant to give simple answers to the most frequent questions raised by practitioners in Europe, including 'practicing allergists', general practitioners and any other physicians with special interest in the management of allergic diseases. It is not a long or detailed scientific review of the topic. However, the recommendations in this pocket guide were compiled following an in-depth review of existing guidelines and publications, including the 1993 European Academy of Allergy and Clinical Immunology position paper, the 2001 ARIA document and the ARIA update 2008 (prepared in collaboration with GA(2) LEN). The recommendations cover skin test methodology and interpretation, allergen extracts to be used, as well as indications in a variety of settings including paediatrics and developing countries.

Skin prick testing (SPT) is the standard method for diagnosing allergic sensitization but is to some extent performed differently in clinical centres across Europe. There would be advantages in harmonizing the standard panels of allergens used in different European countries, both for clinical purposes and for research, especially with increasing mobility within Europe and current trends in botany and agriculture. As well as improving diagnostic accuracy, this would allow better comparison of research findings in European allergy centres. We have compared the different SPT procedures operating in 29 allergy centres within the Global Allergy and Asthma European Network (GA(2)LEN). Standard SPT is performed similarly in all centres, e.g. using commercial extracts, evaluation after 15-20 min exposure with positive results defined as a wheal >3 mm diameter. The perennial allergens included in the standard SPT panel of inhalant allergens are largely similar (e.g. cat: pricked in all centres; dog: 26 of 29 centres and Dermatophagoides pteronyssinus: 28 of 29 centres) but the choice of pollen allergens vary considerably, reflecting different exposure and sensitization rates for regional inhalant allergens. This overview may serve as reference for the practising doctor and suggests a GA(2)LEN Pan-European core SPT panel.

A worm infestation is associated with a reduced frequency of subsequent eczema, especially the atopic type. Furthermore allergic sensitization, especially to house dust mite, and worm infestation are negatively associated. The data support the concept that a lack of immune-stimulation by parasitic infections contributes to the development of allergies.

A farming environment and rural lifestyle might be associated with unknown protective factors impacting the prevalence of allergies.

Background: Perioral dermatitis, a common skin disorder in young women, is rarely described in children. Objective: This study elaborates the clinical features of perioral dermatitis in children as well as possible pathogenetic mechanisms and the response to topical metronidazole. Methods: Seven children (4 females, 3 males between 4 and 12 years of age) were evaluated and dermatological examination was carried out. Pretreatment with topical corticosteroids was documented. Skin prick test with a panel of six common aeroallergens was performed in all children. All children were screened for gastrointestinal colonization with Candida albicans. Patients were treated with topical metronidazole 1% during the first 2 weeks. From the 3rd week on 2% metronidazole was used. Results: In all but one child topical corticosteroids had been used in the face prior to the first presentation at our outpatient department suggesting a possible pathogenetic role. An association with atopy or intestinal Candida colonization was not found. In all children skin lesions resolved after 3–6 months. The children remained free of symptoms over an observation period of 2 years. Conclusion: Perioral dermatitis has to be considered as differential diagnosis in children presenting with erythematous papules and papulovesicles in typical locations. Metronidazole proved to be effective and safe in the treatment of perioral dermatitis in children. Atopy and gastrointestinal colonization with C. albicans do not seem to play a role in the pathogenesis of perioral dermatitis.