Immediate type food hypersensitivity associated with atopic dermatitis in children]

Food allergy is frequently associated with atopic dermatitis (AD) in children. Appropriate elimination diet is necessary in the case of immediate food hypersensitivity, regardless it causes worsening of the chronic eczema or not. Here we report the prevalence of immediate type food allergy diagnosed by oral food challenge or the episodes of apparent acute allergic reaction in the AD patients (n=182, average age 4.9+/-5.1), who visited our clinic within one year. The prevalence of food allergy in the AD patients was 85.7% in age 0 years, 75.6% in age 1,65.4% in age 2, and declined to 13.9% in age 7 years old or more. The offending foods were egg, milk, wheat, fish and so on. The symptoms of food allergy included skin, gastrointestinal or respiratory manifestations, and also anaphylaxis. In conclusion, immediate type food allergy is frequently associated with childhood AD, and appropriate elimination of the offending food is necessary to avoid the acute allergic reaction including anaphylaxis.     

Role of immediate food hypersensitivity in the pathogenesis of atopic dermatitis

Twenty-six children with atopic dermatitis and markedly elevated serum IgE concentrations were evaluated for clinical evidence of hypersensitivity to foods with double-blind placebo-controlled food challenges. Selection of foods for challenges was based on positive prick skin tests (>3 mm wheal) or a convincing history. At least one positive skin test to a food antigen was found in $\text{24}\text{26}$ patients. A total of 111 double-blind placebo-controlled challenges were performed in these children after suspect foods were eliminated from their diets for 10 to 14 days. There were 23 positive challenges in 15 children, 21 of which manifested as cutaneous symptoms, primarily pruritus and an erythematous macular and/or maculopapular rash involving 5% (or greater) of the body surface. In all, 14 children (54%) developed cutaneous symptoms after food challenges. All symptoms occurred within 10 min to 2 hr of challenge; nasal symptoms, mild wheezing, and gastrointestinal symptoms were seen in some children. No symptoms occurred in 104 placebo challenges. There were $\text{86}\text{111}$ clinically insignificant positive skin tests (77%) and three false-negative skin tests. These studies demonstrate that in some children with atopic dermatitis, immediate food hypersensitivity can provoke cutaneous pruritus and erythema, which leads to scratching and subsequent eczematoid lesions.     

The severity of atopic dermatitis and analysis of the food hypersensitivity reactions

Aim of this study is to evaluate the dependence between the occurrence of food hypersensitivity reactions and the severity of atopic dermatitis. The detailed personal history about the food hypersensitivity reactions was recorded and the severity of atopic dermatitis was evaluated with SCORAD index. The statistical evaluation of the dependence between the occurrence of food hypersensitivity reactions and the severity of atopic dermatitis was performed. Two hundred and eighty-five patients were examined – 90 men and 195 women, average age 26.2 (s.d. = 9.5). The significant dependence between the severity of atopic dermatitis and the occurrence of food hypersensitivity reactions was confirmed; 96% of patients with severe form of atopic dermatitis suffer from food reactions. In evaluating the single foods, the significant dependence was found between the severity of atopic dermatitis and the reactions to nuts, apples, and fishes.     

Double-blind placebo-controlled trial of oral cromolyn in children with atopic dermatitis and documented food hypersensitivity

Ten children with challenge-proven egg hypersensitivity and atopic dermatitis were enrolled in a double-blind crossover trial of oral cromolyn sodium. After receiving up to 40 mg/kg/day of cromolyn or placebo for 1 week, patients underwent double-blind placebo-controlled oral food challenges. In the eight subjects who reacted to the food challenge, there was no significant difference in the amount of food allergen eliciting the positive response, the timing of onset until first subjective or objective symptoms developed, symptoms provoked, or the duration of the symptoms in either phase of the study. This study demonstrates no benefit in the treatment of children with atopic dermatitis and food hypersensitivity with oral cromolyn sodium.     

Cutaneous basophil hypersensitivity in atopic dermatitis

The infiltration by basophils into delayed hypersensitivity skin lest sites was examined in patients with atopic dermatitis, contact dermatitis and in normal healthy persons. Atopic dermatitis patients, with large amounts of IgE, injected intradermally with staphylococcal antigens showed reactions that were more transient and erythemaious than those of normal persons. On hislological examination there were numerous, degranulating basophils among the perivascular mononuclear cells. Normal persons, with small amounts of IgE showed typical mononuclear cell infiltration and few basophils. Patients with contact dermatitis, one with much IgE, responded to patch tests to potassium dichromate or to nickel sulphate by delayed type reactions, but on histology, two of the four patients showed a significant infiltration by basophils. It is considered that the erythematous response to the antigen in atopic dermatitis patients is related to the basophil infiltration.     

Atopic march,food allergy and food hypersensitivity in children and adolescents suffering from atopic dermatitis

Increases in allergic diseases have been well documented worldwide. Approximately one-third of children with severe atopic dermatitis (AD) were reported to suffer from IgE-mediated food allergy as well. Data sources concerning the food allergy, AD, and atopic march were accessed from Pubmed/MEDLINE. This review provides a summary of findings concerning the food allergy, food hypersensitivity reactions, and atopic march in children and adolescents. Food allergy that developed at a young age increased the risk for AD, asthma bronchiale, and allergic rhinitis; new research identifies the skin barrier as not only an important initiator of AD but it may even be a site for allergic sensitization to protein antigens. Early childhood is thought to be a key period for the prevention of allergic march and adolescence is another key period for the prevention of recurrence. The prevention of recurrence would decrease allergic disease in adulthood.     

Spontaneous release of histamine from basophils and histamine-releasing factor in patients with atopic dermatitis and food hypersensitivity

Patients with hypersensitivity to food documented by a double-blind, placebo-controlled oral food challenge have been reported to have a high rate of release of histamine from basophils in vitro. To determine whether patients with atopic dermatitis and food hypersensitivity had similar high rates of spontaneous histamine release in vitro, whether dietary elimination of relevant food antigens affected this release, and whether a cytokine, histamine-releasing factor, could account for it, we evaluated 63 patients with atopic dermatitis and food hypersensitivity (38 of whom had eliminated the offending foods from their diets), 20 patients with atopic dermatitis without food hypersensitivity, and 18 normal volunteers. Patients with atopic dermatitis and food hypersensitivity were found to have higher rates of spontaneous release of histamine from basophils than controls (mean +/- SE, 35.1 +/- 3.9 percent vs. 2.3 +/- 0.2 percent; P less than 0.001). Those who had eliminated the offending food allergen from the diet for an extended period had a significantly lower rate of histamine release (3.7 +/- 0.5 percent; P less than 0.001). In patients with atopic dermatitis without food hypersensitivity, the rate (1.8 +/- 0.2 percent) did not differ from that in normal controls. Mononuclear cells from persons with food allergies spontaneously produced a histamine-releasing factor in vitro that provoked the release of histamine from the basophils of other food-sensitive persons, but not from those of normal controls. Patients who adhered to a restricted diet had a decline in the rate of spontaneous generation of the factor by their mononuclear cells. The histamine-releasing factor was found to activate basophils through surface-bound IgE. We conclude that in patients with food hypersensitivity, exposure to the relevant antigens produces a cytokine (histamine-releasing factor) that interacts with IgE bound to the surface of basophils, causing them to release histamine.     

Management of sleep disturbance associated with atopic dermatitis

Atopic dermatitis (AD) is a common childhood skin disease that also affects adults. Sleep problems are frequently associated with AD and negatively affect both patients and their families. Although this problem is well recognized, there are currently limited studies of patients with AD to guide clinical management of sleep disturbances. This targeted review will inform clinicians of the potential therapeutic agents available to manage sleep disturbances and will review literature relevant to improving the sleep of children and adults with AD. On the basis of our clinical experience and the limited data available, we provide a suggested algorithm for clinicians treating sleep problems associated with AD, but clearly more studies are needed to both further characterize the sleep of patients with AD and to test the efficacy and effectiveness of candidate agents in clinical trials.     

Role of food allergy in atopic dermatitis

PURPOSE OF REVIEW: Food allergy and atopic dermatitis often occur in the same patient. Based on clinical data from the past few decades, it is clear that foods such as cow's milk and hen's eggs can directly provoke flares of atopic dermatitis particularly in sensitized infants, whereas inhaled allergens and pollen-related foods are of greater importance in older children, adolescents and adults. Because the role and immunology of food allergy in atopic dermatitis remain controversial, here we review data that mainly focus on skin eczema and food allergy. RECENT FINDINGS: Clinical studies have revealed that more than 50% of all children with atopic dermatitis that can be exacerbated by certain foods will react with a worsening of skin eczema alone or in addition to immediate symptoms. Adolescents and adults also react to foods, but reactions to 'classical' food allergens such as hen's eggs and cow's milk are not as common as in childhood. Subgroups of children and of adults with atopic dermatitis do, however, react to pollen-associated foods. Both immunoglobulin E associated and independent T-cell mediated responses appear to be involved in clinical eczematous reactions. SUMMARY: Food-induced eczema should be diagnosed only by a thorough diagnostic procedure, taking into account the patient's history, the degree of sensitization and the clinical relevance of the sensitization. More clinical and immunological studies are needed to unravel the pathophysiology and the different rates of clinical responsiveness to different foodstuffs in patients with atopic dermatitis.     

Late eczematous reactions to food in children with atopic dermatitis

BACKGROUND: Food allergy is a common problem in patients with atopic dermatitis (AD), particularly in children. While immediate reactions to food are well characterized, the importance of food as a provocation factor for late eczematous reactions has been a subject of debate for several decades. OBJECTIVE: To investigate the importance of food for the induction of late eczematous reactions in children with AD and to correlate the clinical outcome to the results of specific IgE determinations and atopy patch tests (APTs). METHODS: One hundred and six double-blind placebo-controlled food challenges (DBPCFCs) to cow's milk, hen's egg, wheat and soy in 64 children with AD (median age 2 years) were analysed retrospectively. Total and food-specific IgE were determined by CAP RAST FEIA and APTs with native foodstuff were performed. The diagnostic values of specific IgE and APT results were calculated. RESULTS: Forty-nine (46%) of the challenges were related to a clinical reaction. An exacerbation of AD (late eczematous reaction) commonly occurred 24 h after the ingestion of food. Isolated late eczematous reactions were seen in 12% of all positive challenges. Forty-five percent of the positive challenges were associated with late eczematous responses, which followed immediate-type reactions. The sensitivity of food-specific IgE and the APT was 76% and 70%, respectively. Specific IgE and APT were often false positive, which resulted in low positive predictive values (64% and 45%, respectively). CONCLUSIONS: Late eczematous reactions may often be observed upon food challenge in children with AD. Due to the poor reliability of food-specific IgE and APT results DBPCFCs have still to be regarded as the gold standard for the appropriate diagnosis of food responsive eczema in children with AD.     

Diagnostic tests in children with atopic dermatitis and food allergy

Background Skin testing is a common diagnostic procedure in food allergy. The skin prick test is the test of first choice for investigating the immediate IgE-mediated reaction, TTie skin application food test (SAFT) has been developed on the basis of the mechanism of the contact urticaria syndrome (CUS), Methods We studied the relevance of the SAFT in children younger than 4 years with atopic dermatitis and (suspected) food allergy as compared with the prick-prick test, the radioallergosorbent test (RAST), and the oral challenge. In the skin tests, we used fresh food, in the same state as it was consumed.
Results There was a good agreement between the SAFT and the prick-prick test. A moderate agreement was observed between the SAFT and the serologic test (RAST). Significantly more positive results in the RAST were observed than in the SAFT, There was very good agreement between the SAFT and the oral challenge (K = 0,86).
Conclusions The SAFT is a reliable and child-friendly skin test for evaluating (suspected) food allergy in children younger than 4 years with atopic dermatitis. The very good correlation with the oral challenge indicates that one may probably consider the SAFT a "skin provocation" in children younger than 4 years.     

Clinical relevance of food additives in adult patients with atopic dermatitis

BACKGROUND: Adverse reactions to food play an important role in the pathogenesis of atopic dermatitis (AD). In infancy and childhood, food allergies are observed in up to 30%, whereas nonallergic hypersensitivity reactions (pseudoallergic reactions) towards food additives have been reported to occur between 2 and 7%. By contrast, sensitizations towards food allergens are rarely of clinical relevance in adults and little data is available on nonallergic hypersensitivity reactions. To date the role of pseudoallergic reactions as an aggravating factor in AD of adult patients remains controversial. However, many adult patients report on food-related aggravation of the disease and nonallergic hypersensitivity reactions have been incriminated repeatedly. OBJECTIVE: To elucidate the relevance of food additives in adult patients suffering from AD. METHODS: Fifty patients were monitored over 4 weeks under regular diet followed by 6 weeks of a diet omitting known pseudoallergens. Skin status of patients was assessed every 2 weeks by a standardized scoring, and serum eosinophilic cationic protein (ECP) was determined before and after diet. RESULTS: Nine of fifty patients dropped out, 26 showed a significant improvement of the Costa-score by 57%. In 23/26 patients a corresponding reduction of serum ECP level by 52% on average was determined. Responder patients (24/26) were orally challenged with food rich in pseudoallergens followed by double-blind exposure to food additives (n = 15). A worsening of the eczema was seen in 19/24 patients after intake of pseudoallergen-rich food and in 6/15 patients after exposure to food additives. CONCLUSION: These results indicate that a subgroup of adult patients with AD clinically improve on low-pseudoallergen diet but only a small subgroup respond to oral provocation with food additives.