Immunoglobulin E-Mediated Allergy Plays a Role in Atopic Eczema as Shown in the Atopy Patch Test

Abstract

Although the pathophysiology of immunoglobulin E (IgE)-mediated allergic rhinoconjunctivitis and bronchial asthma is rather well established, the role of allergy in atopic eczema (AE) is still controversial. By a technique called atopy patch test, aeroallergens like house dust mite, animal dander, or pollen were proven as relevant trigger factors in a subgroup of patients with AE. The atopy patch test is an epicutaneous patch test with such allergens known to elicit IgE-mediated reactions, and used for the evaluation of eczematous skin reactions. In a series of single-center and multicenter studies, a method was developed, standardized, and compared with other diagnostic techniques (radioallergosorbent test, skin prick test) in AE patients. With regard to clinical history, the most specific results were obtained with the atopy patch test (allergen-dependent, 69%-92%), whereas sensitivity was higher for skin prick test (range, 69%-82%) and specific IgE (range, 65%-94%). The characterization of a patient subgroup with relevant IgE-mediated allergy may lead to more efficient avoidance and eventually even specific immunotherapy strategies in the management of AE.

Elevated Peripheral Allergen-Specific T Cell Response Is Crucial for a Positive Atopy Patch Test Reaction

“…In contrast to food allergy, a gold standard of provocation in aeroallergen-induced AE has not been established. However, as in conventional patch testing, the prospectively obtained history of allergen-induced exacerbations of AE has been used to evaluate the clinical relevance of APT results, revealing a higher specificity despite a lower sensitivity in the APT compared to IgE measurements [11, 12, 14]. APT can thus add valuable information in the diagnosis of AE and identification of relevant allergens.…”

“…The use of the atopy patch test (APT), an epicutaneous patch test utilizing protein allergens known to evoke an IgE response, has been proposed for evaluating the relevance of sensitization to such allergens in AE [10,11,12]. The presence ofIgE+ Langerhans cells in the skin is clamed to be essential for a positive APT [13].…”

“…The presence ofIgE+ Langerhans cells in the skin is clamed to be essential for a positive APT [13]. Interestingly, APT reveals allergen sensitization also in AE patients devoid of detectable allergen-specific IgE, while often more than 50% of AE patients with allergen-specific IgE remain APT negative [11, 12, 14]. This implicates the involvement of other factors complementary to, or interchangeable with, IgE in the APT reaction.…”

Allergen-specific immunotherapy for atopic eczema

“…An epicutaneous patch test with allergens known to elicit IgE-mediated reactions, and the evaluation of eczematous skin lesions [atopy patch test (APT), reviewed in [4]] can be used as a diagnostic tool in further characterizing the reactive subgroup of patients. Atopic eczema shows a genetic predisposition, multiple changes in immune functions, environmental interaction, and a reduced skin barrier function resulting in facilitated contact of allergens with cells of the immune system [1 & ,2].…”

Avaliação do teste de contato com aeroalérgenos em pacientes com dermatite atópica

“…CONCLUSIONS: The atopy patch test shows statistically significant results when performed with dust mites in patients with atopic dermatitis, p = 0.035, odds ratio (OR) = 3.35 and CI (95%) = [1. 18,9, 47].Resumo: FUNDAMENTOS: a dermatite atópica é uma doença inflamatória cutânea que apresenta múltiplos fatores desencadeantes. Há vários relatos de autores que confirmaram os aeroalérgenos como fatores agravantes ou desencadeantes.…”