Atopic dermatitis is a recurrent chronic inflammatory skin
disease with a complex pathogenesis that includes genetic predisposition,
dysfunction of immune and epidermal barriers, and environmental factors.
Itching is the main symptom; skin lesions range from mild erythema to severe
lichenification and erythroderma. Diagnosis is based on history and
examination. Treatment includes advice on proper skin care, prevention of
triggers, and topical corticosteroids and immunosuppressants. It is also
important to control itching and superinfections. In severe cases, systemic
immunosuppressive treatment may be necessary. Atopic dermatitis in childhood
often resolves or decreases significantly in adulthood. bolts.answerhop
Etiology of Atopic
Dermatitis
Atopic dermatitis mainly affects children in urban areas
or developed countries, and its prevalence has increased in the last 30 years;
up to 20% of children and 10% of adults in developed countries are affected.
Most people develop this disease before 5 years of age, many of them up to 1
year; however, atopic dermatitis can begin even in late adulthood. An unproven
hygiene hypothesis suggests that reducing exposure to infectious agents in
early childhood (for example, due to stricter hygiene practices at home) may
increase the development of atopic disorders and self-protein autoimmunity. tc-bolts.dyifo
Many patients or their families with atopic dermatitis
also suffer from allergic asthma and / or immediate hypersensitivity,
manifesting, for example, in the form of seasonal or perennial allergic
rhinoconjunctivitis. The triad of atopic dermatitis, allergic
rhinoconjunctivitis, and asthma is called atopy or atopic diathesis. Other
dermatologic signs of atopy include xerosis, ichthyosis / hyperlinearity of the
palms (i.e. more prominent skin lines on the palms), keratosis of the hair,
infraorbital skin fold (Denny Morgan fold), thinning of the lateral eyebrows
(sign of Hertoge), hair intolerance (irritation and itching caused by
skin-to-hair contact), white dermographism (vasoconstriction that causes
whitening of the skin in response to scratching), and increased transepidermal
water loss (in both unaffected and non-affected skin). in the affected one). techqueer
Pathophysiology of
Atopic Dermatitis
All of the subsequent factors contribute to the
development of atopic dermatitis:
Genetic factors
Dysfunction of the
epidermal barrier. construction-bolts.tockhop
Immunological
mechanisms
Environmental
triggers
The genes involved in atopic dermatitis encode epidermal
and immune proteins. The main predisposing factor for atopic dermatitis is the
presence of a loss-of-function mutation in the gene encoding filaggrin protein
in many patients (1). Filaggrin is a component of the keratinous cell membrane
produced by the differentiation of keratinocytes. This is essential to create
the hygroscopic barrier of the stratum corneum (also called the natural
hydration factor). Approximately 10% of the European population are
heterozygous carriers of loss-of-function filaggrin mutations. The presence of
these mutations (as well as more intragenic copy mutations) increases the risk
of more severe atopic dermatitis and higher IgE levels. Filaggrin mutations
have also been linked to peanut allergy and asthma, even in the absence of
atopic dermatitis. bacobolts.yictic
