Atopy

In medicine, the term atopy is used to refer to the type of immune mechanism present in atopy diseases, which constitute a group of allergic disorders mediated by the effect and action of IgE antibodies on the cells.

Etymology

The term atopy (from the Greek a + topos, "without place", "misplaced") was coined by Arthur F. Coca in 1923 to classify those rare diseases such as allergic rhinitis, eczema and asthma. For Coca, these diseases were different from anaphylaxis and allergy. In short, people are immunologically different from the rest of the population, referring to the allergic part of the atopic individual.

The term allergy (from the Greek allos ergo, altered reaction) is a broader concept that was introduced by Von Pirquet in 1906 to designate the abnormal response that occurred in certain animals against specific substances (allergens) after a previous exposure.

Atopy in its form of dermatitis is currently considered to be of two classes: extrinsic or allergic, with 75% of cases having alterations in the IgE level, increased specific IgE to food and aeroallergens, and alterations in the interlucin profile., association with asthma and rhinitis; and intrinsic atopy, without the previous findings and without association with nasal or respiratory symptoms. The clinical form of the two is impossible to differentiate.

Clinical examples

One of the diseases that one can suffer from is the so-called atopic dermatitis, which consists of a long-term chronic inflammation, often with a clearly familial association, that occurs in parts of the body that are not common, such as in the flexor surface of the joints, soles of the feet or in the palm of the hand. It is usually part of the atopic triad: atopic dermatitis, atopic rhinitis, and asthma.

More and more children, up to 20% in Western countries, suffer from atopy due to early exposure to allergenic products such as perfumes, wool, animals, etc. Although the determining factor is that of an inherited genetic predisposition, feeding with breast milk during the first year decreases both the incidence and severity of the condition, the great increase in atopy being associated with the decrease in breastfeeding. However, there is no evidence to conclusively support this assertion.

Atopy may be an indication of unrecognized and untreated non-celiac gluten sensitivity.

Primary prevention, avoiding exposure to aeroallergens, such as human dander, animal dander, dust mites, and pollen, is helpful in extrinsic atopy, but not as helpful in intrinsic atopy.^{[ citation required]}

As there is no consensus on the exact nature of the condition, management is aimed at suppressing the symptoms, whether respiratory (rhinitis, asthma) or dermatological (atopic dermatitis), and is based on treating the allergic reaction with antihistamines, immunomodulators, emollients, mild topical steroids and, exceptionally due to the risks of their use, with systemic steroids.

Patients with chronic atopic dermatitis have a higher risk of developing addiction syndrome to topical corticosteroids, which often becomes difficult to differentiate from the initial dermatitis. Children are even more prone, so extreme caution is recommended when starting long-term treatment with topical corticosteroids.

The use of immunomodulators such as pimecrolimus and tacrolimus appears to be promising. Worrying reports could suggest an increased risk of lymphoid neoplasms with prolonged use, which calls for caution in their use, until more information is consolidated.

In people with non-celiac gluten sensitivity, a gluten-free diet produces an improvement or remission of the related symptoms, which is an indicator that gluten is the cause in these cases.