Positive Skin Prick Test Reactions Research Articles

Mast cells and IgE in intestinal mucosa in adult atopic dermatitis patients.

Duodenal biopsies from 29 adult atopic dermatitis (AD) patients with multiple positive skin prick test reactions were examined and the results compared with biopsies from 13 non-atopic controls. The duodenal mucosa showed mild inflammatory changes in six out of the 29 patients, but was normal in all the controls. Numerous anti-IgE positive cells, increasing with the severity of AD, were found in the duodenal mucosa in 25 of the 29 AD patients compared with few sporadic positive cells seen in only two out of 13 controls (P less than 0.001). The total serum IgE level showed a significant positive correlation with the number of anti-IgE stained cells in the mucosa (P less than 0.05). No significant differences were found in the total number of toluidine blue stained cells or cells immunoreactive for histamine between patients and controls. However, AD patients who had high numbers of anti-IgE positive cells often had decreased numbers of histamine immunoreactive cells in the mucosa suggesting mast cell degranulation. These findings provide further evidence that also in adult AD patients the gastrointestinal tract may serve as a portal of entry for allergens which may lead to exacerbation of AD.

Allergens from plantain (plantago lanceolata). Studies with pollen and plant extracts.

There has been unjustified neglect of dicotyledonous (dicot; 'weed') pollens in research directed at isolating pure allergens, since dicot pollens are widespread and frequently important in provoking immediate allergic reactions. Sera from patients who showed positive skin prick test reactions to plantain pollen generally also reacted in the radioallergosorbent test (RAST) with at least one other species of dicot pollen. Fractionation of plantain pollen extracts by ultrafiltration and molecular sieving and examination of the fractions by the RAST revealed a spread of allergenic activity. Using crossed immunoelectrophoresis, at least 16 different antigens were detected in plantain pollen and at least 6 of these antigens may be allergenic. Allergenic glycoproteins that react with concanavalin A were isolated and their complexity examined by electrophoresis and electro-focusing. IgE-binding components were found widely distributed in plantain plants and not confined to the pollen.

Dog Serum Albumin as an Allergen

To study the allergenicity of dog serum albumin (DSA) in dog-sensitive subjects, we investigated 203 asthmatic children by means of the skin prick test (SPT), the radioallergosorbent test (RAST) and the in vitro lymphocyte stimulation test. Significant SPT reactions to DSA were observed in only 9 out of 80 subjects with a significantly positive SPT reaction to dog dander and hair (DDH). Analogously, positive DSA RAST results were observed only in a minority of the cases with a positive DDH RAST. Significant SPT reactions to DSA were not observed in subjects with a negative clinical history of dog allergy, or in subjects with a negative reaction to DDH in the SPT or in the provocation test. DSA induced remarkable lymphocyte stimulation in only 1 subject, who also had a significant SPT reaction to DSA. DSA-specific serum IgG antibody titers measured by ELISA were not found to correlate with DSA SPT or DSA RAST.

Asthma and allergy in Finnish conscripts.

We studied the occurrence of asthma, bronchial wheezing, allergic rhinitis and atopic dermatitis in 295 young men aged 18-19 years. The relationship of these symptoms to the immediate skin test reactivity was also determined. Symptoms indicating past or current allergy and bronchial wheezing were observed in 36%. The cumulative prevalence of asthma was 2.7%, bronchial wheezing 9% in addition, allergic rhinitis (including allergic conjunctivitis) 20%, and atopic dermatitis (including allergic urticaria) 20%. Positive immediate skin prick test reactions were observed in 50% of the population. Allergic rhinitis was most clearly connected with a positive skin test. This study shows that the respiratory disorders, generally considered to be allergic in origin, and atopic dermatitis are more common in Finland than has been assumed. The results are, however, in accordance with the observations made in other industrialized countries. Susceptibility to asthmatic reactions and allergic symptoms should be taken into account, more so than at present, when mudging the capability of a young man to manage compulsory military service.

RESPIRATORY ALLERGY TO URINE PROTEINS OF RATS AND MICE

Five atopic laboratory workers with asthma and other manifestations of allergy to rats and mice were sensitive to low-molecular-weight urine proteins—an α 2-globulin in the rat and a prealbumin in the mouse. Positive skin prick and inhalation test reactions to the urine proteins were obtained; and radioallergosorbent tests (R.A.S.T.) for specific IgE antibody were also positive. These findings show that proper control of the collection and disposal of the animals' urine is necessary to minimise the likelihood of sensitisation.