Atopic dermatitis is the number one disease plaguing children’s skin health, accounting for one-third of all pediatric dermatology visits, and has become a child’s skin health problem that requires the attention of parents and doctors alike! The name “atopic dermatitis” may be unfamiliar, but the term “eczema” must be quite familiar. In fact, atopic dermatitis is a special kind of “eczema”. Many infantile eczemas are essentially atopic dermatitis in infancy!
The concept of eczema is broad and is an inflammatory skin condition with a tendency to ooze, with significant itching and recurrence, caused by a variety of internal and external factors. “Atopic dermatitis, also called hereditary allergic eczema, is a chronic inflammatory skin disease associated with hereditary allergic qualities, manifested by pruritus, multiple lesion patterns with a tendency to exude, and it is a triple brother to allergic asthma and allergic rhinitis, called “atopic progression It is called “atopic progression”. It usually starts with atopic dermatitis and tends to develop allergic rhinitis and asthma as it gets older. The disease is intensely itchy and often recurrent, seriously affecting the quality of life of children.
The term “eczema” is only a provisional diagnosis for dermatitis whose etiology is not clear at present. Many diseases with eczema-like manifestations are gradually differentiated from “eczema” and become independent diseases when the etiology is clear or there are specific manifestations. The term “atopic dermatitis” refers specifically to eczema with a family history of allergic disease and a physical condition. In addition to eczema, children with atopic dermatitis often have dry, itchy skin all over the body, and the onset of the disease is specific at different ages.
In dermatology clinics we often encounter parents who are confused: our parents have never had this disease, how can it be passed on to their children? The cause of atopic dermatitis is very complex and still not fully understood. Available studies show that the disease involves a variety of factors including genetics, immune abnormalities, and the environment. Genetics is intrinsic to the disease, while environmental factors are extrinsic factors that promote the onset of the disease, and both interact to cause the disease.
Intrinsic Factors – Genes
Atopic dermatitis is actually a polygenic disease and is not determined by a specific gene. Sometimes parents of affected children do not have it, but someone in the family has it, or there is a defect in some genes that just does not show up. As early as 1916, Professors Cooke and VandeMeer discovered that the incidence of atopic dermatitis in children born to one parent could be more than 25% within 3 months of birth and more than 50% within 2 years of age, and up to 79% if both parents had a history of atopic disease. It is clear that genes play an important role in the development of the disease.
So which gene goes wrong and causes the disease? The skin of our body is like a wall that serves as a skin barrier against external environmental stimuli and protects the stability of the internal environment of the body. The integrity of this function depends on the structure and function of the keratin cytoskeleton (“bricks”), intracellular lipids (“mortar”) and epidermal prion enzymes based on filaggrin (FLG) on human chromosome 1q21. The normalization of the In contrast, children with atopic dermatitis have a functional deficiency of the FLG gene, resulting in a change in the structure of the skin barrier “brick-wall” and a decrease in the ability to retain moisture and water, which prevents the invasion of external environmental irritants and microorganisms and leads to the development of the disease.
External factors – environment
Some parents ask, “Why is the incidence of this disease so high now, when I didn’t think so many children were suffering from it before?
We mentioned earlier that the development of atopic dermatitis is not only a genetic issue, but also a factor of our environment. The rapid global industrialization and changes in people’s lifestyles in the last 30 to 40 years are important factors that contribute to the development of the disease. Certain environmental and food substances such as pollen, dust mites, milk, eggs, cashews, peanuts and seafood are no longer coexisting substances and delicacies for children with atopic dermatitis, but terrible allergens that may cause the organism to have a metamorphic reaction and induce aggravation of the disease.
In addition, we now have a higher standard of living, we pay attention to diligent hand washing and bathing to eliminate germs in the environment and avoid contracting diseases, but we neglect protective measures for the skin (such as moisturizing), leaving the skin in an over-washed state, exacerbating the dryness of the skin, destroying the barrier function and inducing the disease.
What are the specific manifestations of atopic dermatitis? Atopic dermatitis is divided into three clinical stages based on age, site of onset and morphological changes in lesions: infancy, childhood and adolescence and adulthood. The clinical manifestations of the different stages are slightly different and may overlap with each other. Understanding the manifestations of atopic dermatitis at different stages will help parents to better understand the characteristics of the disease.
Atopic dermatitis is divided into three clinical stages based on age, site of onset and morphological changes in the lesions: infancy, childhood and adolescence and adulthood. The clinical manifestations of the different stages are slightly different and may overlap with each other.
Infantile stage (birth to 2 years)
Most so-called infantile eczema (“tinea cruris”) is actually atopic dermatitis of infancy. The rash is mainly on the face, but the scalp, forehead, neck, wrists, and extremities are often involved, showing pruritic erythema, papules, vesicles, oozing, and crusting on top of erythema. The child is often irritable with crying and restlessness due to itching, which can affect sleep. The disease is sometimes severe and sometimes mild, and can be exacerbated by certain food or environmental factors, or secondary infections can occur. The disease usually improves and heals gradually within 2 years of age, but in some cases the disease is prolonged and develops into childhood atopic dermatitis.
Childhood (2~12 years old)
Atopic dermatitis mostly occurs 1 to 2 years after the remission of infantile atopic dermatitis and gradually worsens, while a few continue to occur since infancy. The lesions occur mostly on the flexors of the extremities, with the fossa of both elbows and the N fossa being most commonly involved, commonly known as “four fossa wind”. This is followed by the eyelids, face and front of the neck. The lesions become darker in color and exudate less than in infancy, often accompanied by secondary lesions such as scratch marks, which become hypertrophic over time. At this stage, the skin is very dry and the itching is very intense all over the body, forming a vicious cycle of “itching → scratching → itching”.
Adolescent and adult period (12 years old and above)
Atopic dermatitis in adolescents and adults over 12 years of age, which can develop from childhood or occur directly. It occurs around the eyes (periorbital dark halo), neck, elbow fossa, N fossa, extremities, trunk, and in some patients the palms of the hands and feet (palmar sign). The lesions often appear as limited hypertrophic lesions, sometimes with acute or subacute eczema-like changes. Itching is intense, and scratching results in secondary lesions such as blood crusts, scaling and hyperpigmentation. Most patients have lesions that gradually diminish after the age of 20, but a few severe cases may persist into old age.
In addition, patients with atopic dermatitis may have a range of characteristic skin changes, including dry skin, auricular fissures, ichthyosis, palmar signs, periorbital keratosis, Dennie-Morgan infraorbital folds, periorbital dark halo, white pityriasis and nonspecific hand and foot dermatitis, all of which are specific signs of atopic dermatitis skin manifestations.
Treatment: Glucocorticoid creams are the main drugs for controlling the condition and relieving symptoms, and should be used appropriately according to age and lesion status, while attention should be paid to the possible adverse reactions caused by long-term use. In recent years, topical immunomodulator treatment has also achieved good results. Oral antihistamines can relieve pruritus and reduce scratching to varying degrees, and additional antibiotics are required for secondary bacterial infections. In addition, in addition to medication, moisturizing care is also critical to effectively repair the skin barrier function and reduce recurrence.