Eczematous reactions in atopic patients caused by epicutaneous testing with inhalant allergens

Abstract

To determine whether inhalant allergens could induce eczematous lesions we studied 17 patients with atopic eczema (with or without allergic rhinitis), 13 patients with allergic rhinitis without atopic eczema and 10 healthy control subjects. The allergens, birch pollen (Betula verrucosa) and house dust mite (Dermatophagoides pteronyssinus), were applied in aluminium chambers for 48 h on clinically normal skin. In 17 patients with atopic eczema, six epicutaneous test reactions of the delayed type to birch pollen and three to house dust mite were seen at 48 or 72 h. In 13 patients with allergic rhinitis without eczema there was one delayed reaction to birch pollen and none to house dust mite. No delayed type test reactions to either allergen were seen in the controls. Biopsies of the positive test sites revealed an eczematous reaction with epidermal spongiosis and microvesiculation. Immunostaining of cryostat sections showed dermal cell infiltrates consisting of mainly T lymphocytes (ratio of T4:T8, 2-6:I) and to a lesser degree Langerhans and indeterminate T6+ cells. 50-90% of the cells were Ia+. The numbers of basophils and mast cells did not exceed 10-15%.

The control of allergens of dust mites and domestic pets: a position paper

“…The development of allergen patch tests indicated that antigens of house-dust mites were capable of inducing a delayed-in-time eczematous-type response, and that this involved elements of the immune response additional to IgE antibody [41,42]. As is the case with other atopic diseases, it is now evident that patients with the disorder may posess T-cells sensitized to specific mite allergens [43], and that T-cells are one of the major cell types that infiltrate the skin both in naturally occurring atopic dermatitis and in patch-test reactions [44]. Langerhans cells, the antigen-presenting cells of the skin, possess receptors for IgE antibody [45], and mite allergen has been found attached to these cells [46] which further indicates the overlap between IgE antibody production and cell-mediated immunity.…”

The role of eosinophils in the pathogenesis of atopic dermatitis ‐ eosinophil granule proteins as markers of disease activity

“…tions could be induced by patch tests with environmental allergens (house-dust tnites, grass pollen) as a tnodel for this tnode of triggering AD (3,4,11,31), In these patients, as in LPRs, a significant infiltration of eosinophils in the skin was detected within 2-6 h. By means of monoclonal antibodies against eosinophil toxic proteins, it was shown that these eosinophils were preactivated and that most of their granule content was released into the surrounding tissue. Twenty-four hours after allergen challenge, eosinophils could be detected even in the epidermis.…”

“…As demonstrated by several groups in a number of patients, environmental allergens, e.g. those of grass pollen and house-dust mites, induce eczematous reactions when applied to the skin (4,11,31). Moreover, it was shown that skin contact with these allergens may result in a general exacerbation of AD (1,5,17,26,36).…”

The role of contact allergy to aeroallergens in atopic dermatitis

“…(12) reported the occurrence of positive patch test reactions to a variety of aeroallergens in patients with AD. Other studies investigating the possible role of contact allergy to aeroallergens in the pathogenesis of AD soon followed (13)(14)(15)(16)(17)(18).…”