Atopic Eczema: Everything you need to know about this dermatological disorder.

Atopiceczema is a chronic inflammatory disease non-contagious of the skin, caused by a combination of internal and external factors. It is characterised by periods of flare-ups interspersed with periods of remission. It affects children, adolescents, and adults alike, although the former are the most affected. It is indeed estimated that one in seven children under the age of five suffers from eczema. Several symptoms are characteristic of atopic skin.

• Skin lesions.

  Red and inflamed, eczema lesions appear during flare-ups. They primarily affect the face, neck and neck folds in infants. In adults, eczema can manifest on almost all parts of the body. The skin at the site of the lesions is swollen and itchy. Blisters appear, which then rupture spontaneously or due to scratching. The skin then forms crusts which sometimes become chronic lesions after healing.

• Itching.

  As mentioned above, eczema lesions are accompanied by a significant itching sensation. This itching leads to sleep disturbances and sometimes mood irritability. Some tips fortunately help to alleviate the itch.

• Extremely dry skin.

  An atopic skin is constantly very dry and uncomfortable, even outside of flare-up periods. This extreme dryness is known as xerosis. Emollients play a key role in the management of eczema, as they help to alleviate this dryness and discomfort.

Atopic eczema has a origin genetic. Studies have indeed shown that this form of eczema is often associated with mutations on the genes coding for filaggrin and other proteins essential to the integrity of the stratum corneum. Filaggrin is notably incorporated into the lipid envelope and interacts with keratin filaments. A lack of filaggrin in the stratum corneum is associated with greater transepidermal water loss (TEWL) and a higher capacity for allergens to penetrate the skin. This latter is generally drier, more permeable, and less protected.

Furthermore, approximately 70 to 80% of individuals suffering from atopic eczema have an abnormally high production ofImmunoglobulin E (IgE), antibodies, in response to environmental allergens. When a person is sensitive to an allergen, their immune system produces IgE specific to that allergen. These IgE attach to receptors found on mast cells, immune cells primarily located in connective tissues. Consequently, any exposure to this allergen triggers its binding to the IgE and initiates the release of histamine, a chemical mediator, from the granules contained within the mast cells. This then leads to a cascade of reactions resulting in the typical inflammation of eczema, characterised by redness and itching.

In most instances, eczema is a benign health condition. However, there are complications which, although rare, can be avoided through preventative measures. One such complication is generalised eczema, also known as erythroderma. Eczema is considered generalised when the lesions spread, sometimes covering up to 90% of the body. In addition to the usual redness and itching, oedema can also develop. This form of eczema constitutes a dermatological emergency and sometimes requires hospitalisation.

It is also possible that lesions fromeczema may open and become infected. Microorganisms such as the herpes virus, the staphylococcus aureus bacteria or the fungus candida albicans can colonise the wound, leading to complications. Depending on the type of pathogen causing the infection, this can cause pain and exacerbate itching and redness. It is important to consult a dermatologist in the event of an infection so they can identify the source and prescribe the appropriate treatment (antifungals if it's a fungal infection, antivirals for viral infections and antibiotics in the case of bacterial colonisation).

With appropriate management, atopic eczema can disappear in adulthood. However, most people affected by it experience alternating periods of flare-ups and remission. To alleviate patients and mitigate their symptoms, it is necessary for them to be monitored by a dermatologist. The treatment of atopic eczema often involves the application of topical corticosteroids, cortisone-based creams with recognised anti-inflammatory effects against eczema. It should be noted that these creams are applied only once a day to eczema lesions and only during flare-ups. However, it is advisable to use them at the onset of eczema flare-ups for quick relief.

Some dermatologists also offer phototherapy to alleviate the symptoms of eczema. UVB is generally favoured, although some phototherapy sessions utilise a combination of UVA and UVB, or a pairing of UVA and an oral psoralen, a photosensitising medication.

Finally, some daily habits can help to better manage eczema atopic. It is particularly recommended to apply at least once a day an emollient on the skin. Whether in the form of milk, cream, or balm, this highly nourishing care helps to hydrate and feed the skin deeply to restore its hydrolipidic film, a protective aqueous-oily veil that is missing or scarcely present on atopic skins. The application of cold or certain natural ingredients such as aloe vera or honey can also help to soothe itching.

• GOLDENBERG G. & al. Eczema. The Mount Sinai Journal of Medicine (2011).

• BORRADORI L. & al. Dermatologie et infections sexuellement transmissibles. Elsevier Masson (2017).