The natural history of sensitizations to food and aeroallergens in atopic dermatitis: a 4-year follow-Up

Assessment of dermatological quality of life in patients with childhood atopic dermatitis and their families

Aim

Atopic dermatitis is a chronic, itchy, inflammatory skin disease that progresses with exacerbations. This study was planned to determine how atopic dermatitis affects the quality of life of patients and their families.

Material and Methods

One hundred twenty patients with atopic dermatitis, as diagnosed using the Hanifin Rajka diagnostic criteria, and their families were included in the study. The patients were divided into two groups as active and remission. Disease severity was classified as mild, moderate, and severe according to the SCORAD index. Total IgE, peripheral eosinophil counts, and allergy skin tests were performed. Literate patients completed the Childrens' Dermatology Life Quality Index by themselves. The Infants' Dermatology Life Quality Index was completed by their families. Also, the Family Dermatological Quality of Life Index was completed by one of the parents for each patient.

Results

Among the 120 patients who participated in the study, 76 (63.33%) were male and 44 (36.66%) were female. The mean age was 4.36±3.52 years. The quality of life survey scores were statistically significantly lower in the remission group compared with the active group (p<0.05). The quality of life questionnaire scores were higher in the group with a severe SCORAD index (p<0.05). There was no significant correlation between total IgE, peripheral eosinophil count, skin test results, and questionnaire scores (p>0.05). At least one allergen susceptibility was detected in 65% of the patients who underwent allergy skin tests.

Conclusion

Quality of life was affected negatively in patients with atopic dermatitis and their families. In this study, the quality of life survey results were found to be higher in the active group and the group with a high SCORAD index compared with the remission group and the group with a low SCORAD index. Based on this finding, we can conclude that quality of life is negatively affected by high disease activity.

Skin prick test to foods in childhood atopic eczema: pros and cons

Skin prick tests are the first investigation in allergy diagnostics and their use is described in all the guidelines on atopic eczema. However, the clinical usefulness of skin prick tests is the subject of great debate. On the one hand, skin prick tests allow the identification both of individuals at risk for food allergy and of the allergen inducing the eczematous flare. On the other hand, when performed by a non-specific specialist, positive skin prick tests to foods may wrongly lead to prolonged elimination diets, which may induce nutritional deficiencies and perhaps loss of tolerance to the avoided foods. Furthermore, skin prick tests increase health costs. A consensus on this topic has not yet been reached. Considering the diversity of clinical stages in which it occurs, atopic eczema presentation should be the starting point to determine whether or not skin prick tests should be carried out.

Correlates of outcome for atopic dermatitis

BACKGROUND

The worldwide incidence and prevalence of atopic dermatitis (AD) are increasing. Few good studies have addressed AD in terms of the factors affecting disease prognosis.

OBJECTIVE

To identify significant correlates of persistent AD because this would be clinically valuable information.

METHODS

Potential correlates of AD, including race, onset age, age of solid food introduction, breastfeeding, sinopulmonary infections, other atopic diseases, peripheral eosinophilia, total IgE level, and eosinophilic cationic protein levels, were investigated in 177 patients aged 5 to 18 years. Correlates were compared with AD remission vs nonremission status.

RESULTS

A total of 133 patients (75.1%) were not in remission at the age of 5 years or older and were, thus, classified as having persistent AD. Patients with histories of peanut allergy (odds ratio [OR], 2.92; 95% confidence interval [CI], 1.30-6.55), egg allergy (OR, 2.71; 95% CI, 1.17-6.30), or dust mite allergy (OR, 4.02; 95% CI, 1.84-8.82) were significantly more likely to have persistent AD than those without these factors. There was a trend toward increased odds of persistence in those with peripheral eosinophilia (P = .06) and decreased odds of persistence in those with frequent sinopulmonary infections (OR, 0.51; 95% CI, 0.25-1.03).

CONCLUSIONS

Egg, peanut, and dust mite allergies are significant correlates of AD persisting beyond school age. There may also be increased odds in those with peripheral eosinophilia and decreased odds in those with frequent sinopulmonary infections. This highlights the importance of assessing these correlates in patients with AD and modifying the correlates that can be modified. Further studies on whether modification of these correlates and/or early aggressive AD management improves outcome are needed.

Clinical correlations of recent developments in the pathogenesis of atopic dermatitis

Atopic dermatitis is a chronic inflammatory skin disease with a steadily increasing prevalence affecting 10-20 of infants and 1-3 of adults globally. It is often the first clinical manifestation of atopic disease preceding asthma and allergic rhinitis. Probably half of the children with atopic dermatitis develop some other form of atopic disease later in life. The pathogenesis involves a complex interplay of factors including genetic predisposition due to altered immune or skin barrier function, interactions with the environment such as food and allergen exposures, and infectious triggers of inflammation. In this review, we summarize the recent advances in understanding the contribution of different factors in the pathophysiology of atopic dermatitis and how insights provide new therapeutic potential for its treatment.

IgE-mediated food allergy diagnosis: Current status and new perspectives

In June 2005, the work of the EU Integrated Project EuroPrevall was started. EuroPrevall is the largest research project on food allergy ever performed in Europe. Major aims of the project are to generate for the first time reliable data on the prevalence of food allergies across Europe and on the natural course of food allergy development in infants. Improvement of in vitro diagnosis of food allergies is another important aim of the project. The present review summarizes current knowledge about the clinical presentation of food allergy and critically reviews available diagnostic tools at the beginning of the project period. A major problem in diagnosis is a relatively poor 'clinical specificity', i. e. both positive skin tests and in vitro tests for specific IgE are frequent in sensitized subjects without food allergy symptoms. So far, no in vitro test reliably predicts clinical food allergy. EuroPrevall aims at improving the predictive value of such tests by proceeding from diagnosis based on allergen extracts to purified allergen molecules, taking into account the affinity of the IgE-allergen interaction, and evaluating the potential of biological in vitro tests such as histamine release tests or basophil activation tests including assays performed with permanently growing cell lines.

How atopic is atopic dermatitis?

BACKGROUND

The extent to which the phenotype of atopic dermatitis (AD) is truly atopic has been the subject of much debate.

OBJECTIVE

We sought to systematically evaluate the evidence for the value of measurement of IgE antibodies in diagnosing AD and whether knowledge of IgE sensitization increases clinical diagnostic and predictive ability.

METHODS

We searched Medline from its inception until September 2003. Only studies that measured atopy as either skin prick test positivity or IgE-antibody sensitization to environmental allergens were included within a descriptive analysis. Because the small number of studies of adequate quality did not allow a formal meta-analysis, we assigned strength of evidence according to predefined quality criteria and ranked studies accordingly.

RESULTS

Inclusion of atopy as part of the diagnostic criteria for AD did not enhance the criteria's sensitivity and specificity in relation to the clinical phenotype of AD. The strength of association between atopy and AD varied significantly between hospital studies (47% to 75%; n=14 studies) and was stronger in hospital than in community populations (7.4% to 78%; n=13 studies). Whereas study quality did not have an effect on atopy prevalence in hospital populations, low atopy prevalences in community surveys were seen in less rigidly conducted studies. AD severity was positively associated with the number of positive skin prick test responses or IgE-antibody levels in 7 of 8 studies that measured both. Only one study suggested that IgE-specific sensitization to hen's egg is associated with subsequent development of AD, and 2 studies found that allergen-specific IgE sensitization in patients with AD is a prognostic marker for allergic airway disease in later life. Atopy-associated AD might also have a worse long-term prognosis than AD that is not associated with atopy.

CONCLUSION

Although atopy is clearly associated with AD, the role of IgE sensitization in AD needs further study. Current evidence suggests that up to two thirds of persons with AD are not atopic, which implies that continued use of the term atopic dermatitis is problematic. Longitudinal studies are needed to compare the treatment response and prognosis of IgE-associated and non-IgE-associated AD.

Sensitization to food and airborne allergens in children with atopic dermatitis followed up to 7 years of age

Previously we investigated the eczema prognosis and the risk of developing allergic asthma and rhinitis in a cohort of 94 children with atopic dermatitis. In this second study on the same cohort we address the development of sensitization to foods and airborne allergens, risk factors and, the question whether children with atopic dermatitis who will not become sensitized can be recognized early. Children with atopic dermatitis were followed up regularly from infancy or early childhood to 7 years of age with clinical examination and blood sampling. After age 3, skin prick tests with inhalation allergens were performed yearly. In most children both clinical allergy and sensitization to egg and milk were transient but those to peanut were persistent. Eighty per cent of the children became sensitized to airborne allergens and 75% of them noticed symptoms when exposed. Heredity for atopy and eczema, sensitization to hen's egg, and early onset of eczema entailed an increased risk of becoming sensitized. Children never sensitized had late onset of eczema and less heredity for atopic disease but did not differ in other respects from the sensitized children.

Adult-onset atopic dermatitis in a patch test population

BACKGROUND

Epidemiological studies about atopic dermatitis (AD) almost exclusively relate to childhood disease with little mention of adult-onset disease. In clinical practice, however, patients who have AD and in whom the onset of disease occurs in adult life are sometimes seen.

OBJECTIVE

Because the subjects with a chronic and recalcitrant eczema are frequently patch tested, the aim of this study was to evaluate the prevalence of adult-onset AD in a patch test population and the differences existing between the early- and adult-onset subsets.

METHODS

This retrospective analysis was performed on 502 adults (458 males, 44 females) affected by eczematous dermatitis, consecutively examined in the Department of Dermatology of the Italian Navy Hospital in Taranto. In this department, all the eczematous subjects are routinely submitted to the following tests: standard series (GIRDCA or SIDAPA with integrative haptens), prick test with environmental aeroallergens and common food allergens and dosage of total serum IgE. If it is required, additional series of patch tests are also applied. Many patients are also submitted to the atopy patch test (APT) with whole bodies of house dust mites at a concentration of 20%. In the AD patients, diagnosed according to the criteria of Hanifin and Rajka, the ages of onset were subdivided into the following categories: infancy (0-3 years); childhood (4-11 years); adolescence (> or =12 years). We arbitrarily also used the age of 18 years as the cut-off mark to allocate the patients to the adult-onset group (AOG) and defined as early-onset group (EOG) the cases encompassed in the aforesaid categories (i.e. onset < or =17 years).

RESULTS

8.8% of all eczemas were adult-onset ADs. 28 (5.6% of all eczemas) adult-onset ADs were 'sole' ADs, while 22 cases (3.2% of all eczemas) were adult-onset ADs in which a contact sensitization was detected. The mean SCORAD indexes, according to the age-of-onset groups, decreased when the age of onset increased. No statistical difference was detected between the EOG and AOG with regard to true contact sensitization, clinically relevant or non-relevant contact sensitization, prevalence of 'pure' AD and 'mixed' AD, and outcome of the APT. The hands were the most frequently affected site in the AOG.

CONCLUSION

A small but significant number of patch-test-negative eczematous cases could be adult-onset ADs and, in this instance, the other two allergological tests (i.e. prick tests and dosage of total serum IgE) and an accurate evaluation according to stated clinical criteria should be performed. However, other studies on large series of patients are required to confirm our observation.

Elidel (pimecrolimus) cream 1%: a nonsteroidal topical agent for the treatment of atopic dermatitis

Elidel is a steroid-free cream containing a 1% strength of the topical immunomodulator pimecrolimus. Elidel was specifically developed as a treatment for atopic dermatitis (AD) and is approved for use in children as young as 2 years of age. The production of inflammatory cytokines by activated T cells in skin is thought to play an important role in the pathogenesis of AD. Elidel potently suppresses cytokine production by dermal T cells without significantly impairing systemic immune responses. Elidel does not cause steroid-associated local effects, such as dermal atrophy, striae, or telangiectasia. In randomized controlled clinical studies, twice-daily application of Elidel was shown to significantly improve the signs and symptoms of AD in infants, children, and adults. The clinical effect of Elidel on pruritus, the most troublesome symptom of AD, can be observed within 1 week of therapy and is maintained for the duration of treatment. Elidel is well tolerated; the risk of application-site reactions, such as itching or burning, is comparable with that of the vehicle. Adverse effects were generally mild in patients receiving Elidel and occurred at rates comparable with those in patients receiving vehicle treatment. In a 1-year study, Elidel significantly reduced the incidence of flares when used at the first signs and symptoms of acute AD. As a result, overall corticosteroid use to treat flares was significantly lower in patients using Elidel for early intervention.

A comparison of different allergometric tests, skin prick test, Pharmacia UniCAP and ADVIA Centaur, for diagnosis of allergic diseases in children

BACKGROUND

The diagnosis of allergic disease is performed by skin prick tests (SPT) or through the demonstration of specific IgE in a blood sample via an in vitro test. The measurement of IgE concentration against allergens provides critical information in clinical allergy. Standardized and reproducible methods contribute to the quality of diagnosis and treatment of allergic disease.

METHODS

In this study we evaluated the performance of a new specific IgE method, developed by ALK-Abellò for Bayer Diagnostics to run on their ADVIA Centaur immunoassay system. One hundred and fifty-one children with allergic diseases (both food and inhalant allergies) were tested for specific IgE (sIgE) via SPT and in vitro tests (UniCAP system, Pharmacia, and ADVIA Centaur immunoassay system, Bayer Diagnostics) and the test results were correlated with the clinical data.

RESULTS

Statistical analysis revealed no significant difference between the two in vitro tests compared with clinical history. The sensitivities and specificities are similar, but the UniCAP system method has higher sensitivity. In the children with cow's milk allergy, the UniCAP system has sensitivity of 91% and specificity of 70%; the ADVIA Centaur immunoassay has sensitivity of 82% and specificity of 74%. In hen's egg allergy, UniCAP system has 94% sensitivity and 64% specificity, and the ADVIA Centaur system has 88% sensitivity and 52% specificity. In inhalant allergies, the two methods show statistically similar performances for both grass pollen allergies (UniCAP sensitivity 100%, specificity 73%; ADVIA Centaur sensitivity 95%, specificity 79%) and in the dust mites allergies (UniCAP sensitivity 91%, specificity 62%; ADVIA Centaur sensitivity 86%, specificity 64%). In cat allergies, the systems showed equivalent results (UniCAP sensitivity 100%, specificity 71%; ADVIA Centaur sensitivity 100%, specificity 70%). Using the UniCAP system, the geometric mean of sIgE values in children with clinical allergy is significantly higher than in sensitized ones. The ADVIA Centaur system shows a similar trend with the exclusion of cow's milk and Dermatophagoides farinae allergens. With this last method the mean value of sIgE is higher in sensitized than in symptomatic children.

CONCLUSION

The new ADVIA Centaur method compares favorably with the results obtained on the UniCAP system. If other studies continue to confirm this data, then the advantages are numerous: the use of only a small quantity of serum (25 micro l per allergen), rapid turnaround time, minimal hands-on time, and no interference from IgG.

Immunotherapy in atopic dermatitis

Atopic dermatitis (AD) is a common inflammatory disease involving the skin and often other organs and systems, mainly respiratory. A definitive general consensus on the AD pathogenesis has not yet been established, however several lines of evidence suggest that T-cells play a crucial role in priming AD early-stage lesions. Main topics involved in the disease pathogenesis have been reviewed, which considered the concept of local and systemic haemopoietic events as important contributors to allergic inflammation, a concept now achieving great acceptance. The recently recognised atopic nature of the skin inflammation in AD has raised increasing interest for treatment with allergen-specific immunotherapy. However, we only found eight studies using specific immunotherapy (SIT) in AD, two double-blind, placebo-controlled (DBPC) and six observational. One controlled and five observational reported favourable outcomes. The one unique study providing negative results was flawed by the ineffective oral route of extract administration. Despite being encouraging, the reported results do not allow definitive conclusions based on meta-analytic techniques because the amount and quality of information in the literature is not sufficient. The highly promising sub-lingual immunotherapy (SLIT) is discussed with its potential capability of controlling not only the skin lesion severity but also its capability of preventing the development of atopic dermatitis into asthma.