Sensitization in childhood atopic disease identified by Phadebas RAST, serum IgE and Phadiatop

Abstract

A search for IgE antibodies was performed in 224 children, aged 0–15 yr, with symptoms compatible with IgE‐mediated allergy, employing total IgE. RAST with up to 17 allergens and the Phadiatop® test. Fiftysix of 113 children (50%), aged 0–3 yr, and 80 of 111 children (72%) aged 4–15 yr had specific IgE antibodies. The most common allergens during the first 4 yr were egg white, a mixture of nuts (hazel nut, peanut, almond, coconut and Brazil nut) and milk. During the 2nd yr of life inhalant allergens became more important. From the 3rd yr they became more common than food allergens as sensitizers. Among the children aged 4–15 yr timothy, cat and nut mix were the most common allergens. Among the children with specific IgE antibodies Phadiatop was positive in 58% of the children younger than 4 yr, and in 91% of the children over that age. Fifty‐three of the children with IgE antibodies against nut mix were further investigated for antibodies against hazel nut, peanut and almond, and 48 (91%) were positive against at least one of them. The parents of 41 of these patients answered a questionnaire about adverse symptoms against nuts, and 26 (63%) were aware of clinical sensitivity. In conclusion, IgE antibodies against food allergens dominated in children under 2 yr, and thereafter antibodies against inhalants became more important. An unexpectedly high prevalence of IgE antibodies against nut mixture was found. Phadiatop was a good screening method for identification of children 4 yr or older with IgE antibodies against inhalants.

Vernal keratoconjunctivitis in a Stockholm ophthalmic centre ‐ epidemiological, functional, and immunologic investigations

“…The allergen sensitivity pattern of the atopic VKC subjects showed similarities to that of allergic children in Sweden reported previously (Sigurs et al 1990). Pollen plants and furred animals were the major sources of sensitisation.…”

“…The allergen screening of the in vivo and in vitro tests always included major air-borne allergens such as pollens, animal danders, mites, and molds. In most instances the in vitro search for specific IgE was preceded by the Phadiatop A screening test (Pharmacia CAP System) which has a high precision in detecting presence of specific IgE to common inhalant allergens in individuals above the age of 6 years (Sigurs et al 1990). In 89% of the subjects, sensitisation to food allergens was assessed with SPT and/or serum analyses against a mixture of 6 common alimentary allergens (fx5 A , Pharmacia CAP system, RAST FEIA).…”

Atopic family history. Validation of instruments in a multicenter cohort study

“…The validity of a questionnaire about manifestations of atopic disease was tested by applying a different instrument: the Phadiatop test screens sensitization against the inhalant allergens, which play a predominant role in atopy after 3 years of age (12). Because only a small portion of adults is sensitized exclusively against food allergens the Phadiatoptest has been used successfully to identify most atopic adults: evidence for its suitability has been given in several clinical settings (11), and in a mass screening of 600 recruits in Italy (13).…”

Development of atopic disease during childhood and its prediction by Phadiatop Paediatric

“…Furthermore, of 36 infants with clinical signs/symptoms of respiratory allergy only 50% (18/36) had positive SPTs to pollens and/or animal danders. Thus, like Ruiz et al [8], Wood et al [19] and Sigurs et al [29],we suggest that, when using in vitro tests measuring the presence of IgE-ab (like Phadiatop Paediatric) as an atopy-predictive marker, one should distinguish between an infant with only clinical signs/ symptoms ofatopic disease ('clinical atopy'; CA-group) and an infant with a positive in vivo test, such as SPTs ('atopy'; A-group).…”

“…During childhood, hypersensitivity reactions are mainly IgE-mediated allergies and, even in very young infants, inhalant allergens in addition to food allergens may play an important role [19]. Phadiatop Paediatric (PP), an in vitro test for atopy which detects circulating IgE-ab against both food and inhalant allergens, has been introduced for the diagnosis of childhood atopy.…”