Food-induced contact urticaria syndrome (CUS) in atopic dermatitis: reproducibility of repeated and duplicate testing with a skin provocation test, the skin application food test (SAFT)

IgE-mediated contact urticaria syndrome (CUS) is one of the manifestations of allergy in childhood atopic dermatitis (AD). Allergens such as foods and animal products penetrate the skin easily. They can then cause urticarial reactions in sensitized individuals. A provocation test system for foods, called the skin application food test (SAFT), has been developed. Over more than 5 years, a group of 175 patients with AD was built-up and investigated in a prospective follow-up study with SAFT. SAFT was more frequently positive in AD children aged 6–2 years than in older children. In several children of this population (Group 1), we repeated SAFT within a period of 1 year. In another unrelated group of children (Group 2–1), we compared the results of 'original' SAFT and SAFT using square chambers (Van der Bend) or Silver patches. In the 3rd group (Group 2–2) we compared'original' SAFT with SAFT using big Finn Chambers. The agreement between the tests was high: in Group 1, we observed 88 to 93% concordant scores, and in Group 2, the scores were 96% to 100%. Statistically, the K coefficient ranged from 0.71–0.87 in Group 1, and from 0.83–1.00 in Group 2. SAFT is therefore highly reproducible. Agreement was at least 88% between the scores (the lowest K value observed was at least 0.71).     

Allergy to pine nuts in a bird fancier

A patient is described with the bird-egg syndrome who experienced an anaphylactic reaction after eating some of her parrot's food (pine nuts: Pinus pinea ). Specific IgE against this nut and another pine nut ( P cembra ) was demonstrated by RAST. Cross-reactivity between these botanically related seeds was shown by RAST inhibition. Besides avian antigens, bird food antigens should be taken into consideration when symptoms of allergy occur on exposure to birds.     

Occupational pollinosis in gardeners

The symptoms of occupational pollinosis are described on the basis of case histories, skin tests and serological tests of six commercial gardeners. Exposure to gerberas, freesias, chrysanthemums and to genera of the nightshade family (Solanaceae) such as paprikas, tomatoes, egg plants and potatoes may lead to allergy with raised IgE levels.     

Nasal hyper-responsiveness to histamine, methacholine and phentolamine in patients with perennial non-allergic rhinitis and in patients with infectious rhinitis

Recently it has been shown that patients with atopic rhinitis and with an allergy to house dust mites have a stronger nasal response to insufflation of histamine, methacholine and phentolamine than a control group. This hyper-responsiveness could not be demonstrated in patients with perennial non-allergic rhinitis, unless the patients were selected according to the predominant symptoms in the history. Patients with rhinorrhoea ('runners') proved to be hyper-responsive to methacholine compared with normal controls. The existence of two subpopulations was emphasized by hyper-responsiveness to both histamine and methacholine in the runners group compared with the patients with a stuffy nose ('blockers'). Patients with chronic nasal infections (characterized by recurrent episodes of purulent discharge) showed no hyper-responsiveness at all, indicating that either hyper-reactivity does not play an important part in this patient population or methods to detect hyper-reactivity in this group are inadequate. In contrast to our earlier observations in patients with atopic rhinitis, increased responsiveness to phentolamine could not be detected either in the patients with perennial rhinitis or in the patients with infectious rhinitis, indicating that the possible alpha-adrenergic dysfunction found in patients with atopic rhinitis is restricted to this group.     

Isolated early response after nasal allergen challenge is sufficient to induce nasal hyperreactivity.

Ten rhinitic patients allergic to grass pollen were challenged with histamine intranasally 24 hours before and 24 hours after nasal provocation with grass pollen. Up to ten hours after allergen provocation nasal lavage fluid was obtained to characterize early and late phase reactions by measuring the levels of histamine and leukotrienes as indicators of mediator release, and albumin as a marker of increased vasopermeability. Ten minutes after allergen challenge with 10,000 BU grass pollen extract LTC4,D4, and albumin significantly increased from 62 to 576 pg/mL (P = .008) and from 15 to 81 micrograms/mL (P = .008), respectively, without significant changes after placebo challenge a week earlier. Although the patients showed increased responsiveness to histamine after allergen challenge compared with a placebo-challenged control group (P = .02), one patient only demonstrated a late phase nasal allergic reaction characterized by recurrence of clinical symptoms eight to ten hours after allergen challenge and recurrence of mediators in lavage fluid. It is concluded that an isolated early response after allergen challenge is sufficient to induce nasal hyperreactivity. A biochemically or clinically defined late phase allergic reaction does not necessarily accompany allergen-induced hyperreactivity.     

Occupational allergy to pancreatic powder: characterization of IgE-binding antigens in pancreatic extract by immunoblotting.

The IgE response to inhaled dust of pancreatic powder was studied with sera from two employees of a pharmacy. IgE from both sera was directed against both porcine and bovine trypsin preparations. The major IgE-binding structures had an isoelectric point in the pH 8 to 9 range. The molecular weight of the IgE-binding structures was different for both patients. In one patient, most IgE was directed against a 28 to 30 kd structure, whereas the second patient had IgE directed against components with a molecular weight of 35 and 45 kd, respectively.     

Irrelevant IgE binding to cellulose discs in RAST

This study describes two sera that showed irrelevant IgE binding to all allergen-coated cellulose discs tested. This irrelevant IgE binding was not observed when allergen extracts were coupled to agarose beads. Such irrelevant IgE binding can be detected using human serum albumin-coated discs.