Eyelid dermatitis: Work-up and future diagnostic innovative solutions.

Atopy patch testing--a diagnostic tool?

Influence of Age on the Outcome of the Atopy Patch Test with Food in Children with Atopic Dermatitis

Allergic skin diseases

Atopic eczema (AE) is a common skin disorder. Eczematous lesions showing macroscopic, microscopic and immunopathological resemblance to lesional AE can be induced by aeroallergens by epicutaneous testing (atopy patch test, APT). Altered epidermal barrier function, as determined by transepidermal water loss (TEWL), is a typical feature of patients with AE. The present investigation was performed to define the differences in the epidermal barrier function between positive APT reactions to aeroallergens and positive patch test reactions to contact allergens in AE patients. Allergen extracts from grass pollen, birch pollen, cat dander and house dust mite (Dermatophagoides pteronyssinus) were applied in large Finn chambers on Scanpor for 48 h on the clinically unaffected and untreated skin of the back, in 11 patients with AE. The same procedure was done with 27 contact allergens of a standard test battery. Test reactions were read and TEWL was measured after 48 and 72 h. Eight of the 11 patients developed positive APT reactions to D. pteronyssinus, two to cat dander and one to birch pollen. Seven of the 11 patients showed positive patch test reactions to nickel sulphate, two to potassium dichromate, one to thiuram-mix and one to paraphenylenediamine. Vehicle controls were negative. The TEWL of the positive APT reactions was significantly higher, both after 48 h (mean +/- standard deviation 10.0 +/- 6.5 g/m2h) and after 72 h (9.7 +/- 5.4 g/m2h) as compared with the control site (48/72h: 4.4 +/- 1.5/4.1 +/- 1.4 g/m2h) (P < 0.01). In contrast, TEWL of the positive patch test reactions to contact allergens (48/72 h: 5.4 +/- 2.2/5.4 +/- 1.9 g/m2h) was similar to that of the control site (48/72 h: 5.2 +/- 2.1/5.0 +/- 1.8 g/m2h) (not significant). The relative TEWL at 48 h and 72 h, expressed as the ratio between the positive patch test and the control site, was significantly higher in the positive APT reactions (48/72 h: 218.8 +/- 80.4%/232.0 +/- 85.9%) compared with positive patch test reactions to contact allergens (48/72 h: 102.1 +/- 12.0%/107.1 +/- 9.5%) (P < 0.01). It is concluded that the epidermal barrier function in AE patients is altered only in positive APT reactions, in contrast to positive patch test reactions to contact allergens. As a consequence of this aeroallergen-induced altered epidermal barrier function, further allergens can more easily penetrate the skin, inducing a vicious circle and perpetuating the eczematous lesions.

BackgroundA subset of patients with positive patch tests demonstrates systemic contact dermatitis (SCD) upon ingestion or inhalation of the allergen. Concern has been raised about the use of patch tests for protein allergens (APTs) to detect SCD in atopic dermatitis (AD) patients.MethodsWe present atopy patch test (APT) data for 97 people. We reviewed APTs and tests for antigen‐specific immunoglobulin E (IgE) to the same allergen in pediatric AD patients. We compared the frequency of APTs as a function of age in AD patients. To study the irritancy potential of APTs, we prospectively tested consenting non‐AD dermatitis patients undergoing evaluation for allergic contact dermatitis and healthy controls to an APT panel.ResultsAPT demonstrated fewer positive results than serum‐specific IgE or skin prick tests to the same allergen. Positive APT to food was more common in children under 3 years, whereas positive APT to aeroallergens were more common in teens and adults. Only positive APTs to dust mite were significantly more common positive in subjects without AD.ConclusionOur aggregate findings suggest that most APTs, but not dust mite, behave like conventional patch tests to low‐potency allergens. They are more likely to be positive in patients with chronically inflamed skin and to identify allergens that cause SCD. The higher prevalence of APT positivity to foods in young children is consistent with food allergy as a trigger of AD (also known as SCD) being more common in children than adults. Positive APTs define patients who may have SCD; negative APTs may guide elimination diets.

The atopy patch test (APT) is generally used to assess immunoglobulin E (IgE) mediated sensitization to allergens in patients with atopic dermatitis, but its diagnostic role in children with respiratory allergy is still controversial. The aim of the study was to evaluate APT with house dust mite (HDM) in children with asthma and rhinitis symptoms allergic to HDM and its relevance to skin prick test (SPT) diameters and specific IgE levels. The study population consisted of 33 children, aged 8-16 yr (median: 12 yr) with asthma and 30 children with allergic rhinitis in the same age range (median: 11 yr). All patients had positive SPT results and high serum specific IgE levels for Dermatophagoides pteronyssinus APT was performed on back skin of all patients with 200 index of reactivity (IR)/ml of D. pteronyssinus allergen extracts in petrolatum (Stallerpatch) and evaluated at 72 h. Of 63 patients, 16 (25%) showed a positive patch test result. APT with HDM showed 30% (10/33) positivity among the patients with asthma and 20% (6/30) positivity among the patients with allergic rhinitis. APT presented no significant correlation with age, SPT diameter, serum total and specific IgE levels for D. pteronyssinus, nasal provocation test or pulmonary function test results. Patch testing with HDM may partly identify mite sensitive children with respiratory allergy. Positive APT results may imply that delayed hypersensitivity reactions play a role in children with asthma and rhinitis allergic to HDM.

Background: The atopy patch test (APT), namely the patch test with aeroallergens, is regarded as specific for patients with atopic dermatitis (AD), but small numbers of positive APT were reported in the past also in atopic subjects without dermatitis and in healthy persons. Objective: The aim of this study was to evaluate the response to the APT with house dust mites (HDM) in subjects nonaffected by AD and to compare the outcomes observed in these cases with those pointed out in AD patients, evaluating also the differences between two allergen extracts manufactured at different purifications and concentrations. Methods: Forty-seven atopic subjects without eczema (AWE), 33 nonatopic (NA) subjects and 77 adult AD patients were patch tested with an extract of purified bodies of HDM at 20% and with another extract of whole bodies of HDM at 30%, the latter corresponding to 300 µg/g of Der p 1. The reproducibility of APT was also tested in 8 AD patients, in 37 AWE subjects and in 19 NA subjects. Results: Positive responses with extract at 20% were observed in 29 (37.7%) AD, in 5 (10.6%) AWE and in 4 (12.1%) NA subjects. The APT with HDM at 30% was positive in 32 (41.6%) AD, 9 (19.1%) AWE and 4 (12.1%) NA persons. The rates of positivity and the intensity scores of responses were significantly different between AD and non-AD subjects (p < 0.01). The reproducibility of the APT in the three groups was satisfactory. Conclusion: These observations lead to conclude that the APT with HDM is positive also in non-AD subjects but it is probably more specific for AD.

Eyelid dermatitis in patients referred for patch testing: Retrospective analysis of North American Contact Dermatitis Group data, 1994-2016

In human patients with atopic dermatitis, the development of inflammation after epicutaneous application of allergens is dependent upon the presence of IgE and Langerhans’ cells. The purpose of this study was to investigate the role of allergen‐specific IgE in the generation of positive patch test reactions in experimentally sensitized IgE‐hyperresponsive beagle dogs. Patch tests were performed on seven dogs with Dermatophagoides farinae (Df) and flea saliva (FS) allergens or saline control. Two of the dogs had elevated serum IgE against Df, one against FS, two against both and two were not hypersensitive to either allergen. Positive macroscopic reactions consisted of erythema, oedema and induration, and developed between 24 and 96 h after allergen application. Macroscopic and microscopic patch test reactions developed only when serum IgE was present against tested allergens. Serum IgE levels were positively correlated with dermal cell counts at 48 h (Spearman r = 0.59; P = 0.03) and 96 h (r = 0.68; P &lt; 0.01) after challenge. In Df‐sensitized dogs, positive patch tests were associated with numerous IgE‐staining epidermal and dermal dendritic cell aggregates. Dendritic cells positive for IgE also expressed CD1c, identifying cells as Langerhans’ cells. These observations suggest that the development of positive patch test reactions are IgE‐dependent, and that macroscopic and microscopic patch test lesions resemble those seen in dogs with spontaneously‐arising atopic dermatitis. ‘Atopy Patch Tests’ therefore could provide a good model for investigating the pathogenesis and treatment of atopic skin lesions in the canine species. This study was supported, in part, by Heska Corporation.

House-dust mite antigen on skin and sheets

Relationship between skin prick and atopic patch test reactivity to aeroallergens and disease severity in children with atopic dermatitis

In recent years considerable interest in the pathogenetic role of aeroallergens exacerbating atopic dermatitis (AD) has emerged. The 'atopy patch test' with aeroallergens was introduced by Platts-Mills et al. as an experimental model and as a diagnostic tool. However, its relevance for the clinical manifestation of AD is still not clear. We asked whether there is a relationship between the individual antigen exposure to the major allergen of Dermatophagoides pteronyssinus (Der p 1) and the immunological markers of sensitization to Der p 1 or the clinical severity of AD. We investigated 92 patients with moderate to severe AD. For clinical evaluation the SCORAD severity score was used. Patch tests were performed with purified Der p 1. Specific IgE was measured by a commercial assay. Der p 1 exposure was quantified in a sample of the patient's mattress dust by using a commercial ELISA. No correlation between SCORAD, Der p 1 exposure and RAST could be established. However, there was an unexpected significant inverse correlation between the quantity of mite antigen in the mattress dust and patch test reactivity. Patients with a high antigen load (> 25 microg/g) mostly had a negative patch test. Also, when Der p 1 was correlated to the mattress area (m2) in this group all patch tests were negative. A possible explanation could be that continuous exposure of the skin to house dust mite allergen Der p 1 may induce a down-regulation of the skin immune system of patients with AD. Although the mechanism of this phenomenon is presently unknown, our study shows that a positive allergen patch test alone should not be an indication to undertake allergen exclusion measures in AD patients.

Background The aim of this study was to evaluate the positivity rates of atopy patch tests for Dermatophagoides pteronyssinus, Dermatophagoides farinae and Blomia tropicalis in patients with respiratory diseases such as asthma and allergic rhinitis with or without atopic dermatitis.Methods The patients’ clinical histories were collected, and the patients were subjected to skin prick and patch tests with the three different house dust mites on the same day. The patch tests were examined 48 hours later, and then patients were divided into two groups: I- patients with respiratory diseases, such as asthma and/or rhinitis, and atopic dermatitis and II-patients with only respiratory diseases. A total of 74 patients ranging in age from 2 to 60 years were included in this study; 16 patients were included in group I and 58 were included in group II. This study was approved by the human ethics committee of the Faculty of Medical Science and Health SUPREMA (number 2.007.135), and written informed consent was collected from each patient or their parents prior to enrollment.Results In the skin prick tests, the most prevalent mite that evoked a reaction was Dermatophagoides pteronyssinus, followed by Dermatophagoides farinae and Blomia tropicalis. Regarding the atopy patch tests, the mite that most frequently induced a positive reaction was Dermatophagoides farinae (78.4%), followed by Dermatophagoides pteronyssinus (77%) and Blomia tropicalis (52.7%). A comparison of the skin prick and atopy patch tests revealed that 53 patients (71.6%) were positive on both tests, and 30 (56.6%) patients were positivite for the same mite. We found six patients (8%) who had a positive clinical history of allergy and only exhibited positivity on the atopy patch test.Discussion Most studies have been performed with atopic dermatitis patients, but in this study, most of the patients had respiratory conditions. Blomia tropicalis is a mite that is prevalent in tropical areas, such as Brazil, and only two publications include these three mites, wich are present in Brazil. The APT may produce positive results in concordance with the SPT resuts, but may also be the only positive test ( 8%) as we observed in our study. These results suggest that the mite atopy patch test is relevant and should be considered as an additional test for patients with clinical histories of allergic respiratory disease who have negative prick test results.Conclusion The APT should be considered as an additional test when the SPT and specific serum IgE tests are negative in patients with clinical histories of allergies.

Eosinophilic Esophagitis In The Puerto Rican Pediatric Population

Eyelid Dermatitis: Contact Allergy to 3-(Dimethylamino)propylamine