Eczema

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1], Associate Editor(s)-in-Chief: Edzel Lorraine Co, DMD, MD[2]

Eczema, also known as atopic dermatitis, or [atopic eczema]], is a dermatologic problem which is commonly seen in children. It is a relapsing-remitting skin problem that is predominantly manifested as pruritus, with accompanied swelling, redness, and dryness of the skin. Flaking, cracking, oozing, blistering or bleeding may occur as a result of excessive scratching of the skin.

It was in the 20th century when eczema came into existence, and later on, concepts on this had evolved including major insights on the nature of the disease.

Eczema is classified according to location, appearance, or etiology.

The mechanism of disease of eczema involves a complex interplay of abnormalities of skin microbiomes, a dysfunction in the epidermal barrier, and an immune dysregulation. There are two main theories on the existence of atopic dermatitis, also known as atopic eczema – the inside-out hypothesis, and the outside-in hypothesis.

The etiology of eczema is multifactorial and complex. This involves aberrations in genetic component, adverse effect of certain medication and some environmental factors.

Eczema has various mimics with regards to the clinical presentation, severity, and course of disease. A strong clinical evaluation by the physician based on the presenting signs and symptoms is needed to come up with the correct diagnosis. Differential diagnoses of eczema include infectious disease, inflammatory disease, immunodeficiency problem, or a nutritional deficiency.

In the United States, eczema has a prevalence of 10.7% in children and 7.2% in adults. Eczema has more predilection in males.

Risk factors of eczema include family history and FLG gene mutation.

Hanifin and Rajka criteria are the gold standard for diagnosing eczema.

Eczema has regarded as a medical condition with a natural history that occurs consistently. It is characterized as a disease with an early onset, mostly during the childhood period, and remits during the adolescence period. If left untreated, eczema can lead to viral, bacterial and fungal infections. Psychological problems could also arise brought about by constant itching.

Family history, dietary habits, lifestyle habits, and allergies should be elicited whenever considering eczema as the primary diagnosis. This is important because eczema can be based on the patient‘s history and evolution and distribution of the skin lesion.

Eczema is a [dermatologic disease]] and pruritus is the hallmark feature of this disease.

Levels of IgE are associated with allergy, aside from parasitic infections, autoimmune diseases, and certain carcinomas.

No particular biomarker is reliable to diagnose eczema. However, the current practice is by using the laboratory levels of IgE, which when elevated, can also be associated with allergy, aside from parasitic infections, autoimmune diseases, and certain carcinomas.

Topical corticosteroids are the mainline treatment for eczema. Different potencies of steroids are rendered specifically for the severity of eczema. Other drug treatments oftenly used for eczema include topical calcineurin inhibitors,crisaborole, antimicrobials, and antifungals.

Surgical treatment is not commonly used as a means of management for eczema.

Primary prevention is the most effective means to avoid complications of eczema. Emolients and consumption of prebiotics and probiotics can prevent the occurrence of this condition.

Prevention of further trans-epidermal water loss is the cornerstone of management of eczema. Since dysfunctional skin barriers could lead to water loss, daily replenishment of skin moisture is needed. This can be achieved through different modalities such as emollients, occlusives, and humectants.

The economic impact of eczema causes a burden to patients suffering from this disease. A recent study showed that an average of $274 ($199 indirect cost, and $75 direct cost) is spent by each patient for eczema.

Pruritus and constant scratching of the skin can significantly affect the social life of patient. Sleep disturbances, attention-deficit/hyperactivity disorder, headaches, daytime fatigue, and stunted growth are commonly seen in these patients and could lead to embarrassment and poor self-esteem.

Future trends will focus more on genetic studies in eczema.

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1], Associate Editor(s)-in-Chief: Edzel Lorraine Co, DMD, MD[2]

It was in the 20th century when eczema came into existence, and later on, concepts on this had evolved including major insights on the nature of the disease.^[1]

• It was in the 20th century when eczema came into existence, and later on, concepts on this had evolved including major insights on the nature of the disease.^[1]
• Listed below is a summary of the history of eczema.

 " certain degree of hardness of the skin with pustules, some humid and some dry  "

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1], Associate Editor(s)-in-Chief: Edzel Lorraine Co, DMD, MD[2]

Eczema is classified according to location, appearance, or etiology. We have more common causes of eczema, such as seborrheic dermatitis, and less common causes such as dyshidrosis.

• National Eczema Association classified eczema into different types.
• Table 1 enumerates the common types of eczema with their corresponding description.^[1]

• Table 2 highlights the lesser common types of eczema with their respective features.

“Dyshidrotic eczema – Symptoms and causes | National Eczema Association”.

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Edzel Lorraine Co, DMD, MD[2]

The mechanism of disease of eczema involves a complex interplay of abnormalities of skin microbiomes, a dysfunction in the epidermal barrier, and an immune dysregulation. ^[1] There are two main theories on the existence of atopic dermatitis, also known as atopic eczema – the inside-out hypothesis, and the outside-in hypothesis.

• Affected skin involves the uptake of antigens and allergens by the epidermal dendritic cells, dermal dendritic cells, and Langerhan cells.
• Sensory nerves are activated by the released cytokines interleukins 4,13 and 31 (IL-4, IL-13, and IL-31), which are responsible for the pruritic sensation.
• As the event becomes chronic, an increased expression of keratinocyte and Th-cell-derived cytokines is achieved, with more pruritogens contributing to itch sensation. ^[1]

• There are 34 genetic loci which are thought to be associated with eczema.
• These regions contain several genes which have important immunological functions, such as T-cell activation, type-2 helper cell differentiation, and innate immunity. ^{[2] [3][4]}

• Multiple factors cause the disruption of epithelial barrier. These include:
  • FLG mutations
  • Constant scratching
  • Microbial dysbiosis brought about by Staphylococcus aureus and Malassezia.
• As a result, an interrupted normal skin barrier with elevated pH, high skin permeability, altered lipid composition, and decreased water retention is observed. ^{[5] [6] [7] [8] [9] [10]}

• There are two main theories on the existence of atopic dermatitis, also known as atopic eczema – the inside-out hypothesis, and the outside-in hypothesis.^[11]
• Inside-out hypothesis
  • This hypothesis denotes that some allergic triggers weaken the skin barrier that leads to more introduction of allergens to the area, causing more inflammatory reaction.^[11]
• Outside-in hypothesis
  • This hypothesis suggests that an impairment of the skin barrier should occur first before the onset of atopic dermatitis.
  • This involves the down-regulation of filaggrin genes (FLG) responsible for maintenance of the proper function of skin barrier.^{[11] [12]}

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1], Associate Editor(s)-in-Chief: Edzel Lorraine Co, DMD, MD[2]

The etiology of eczema is multifactorial and complex. This involves aberrations in genetic components, adverse effects of certain medications, and some environmental factors.

• Damage from the enzymatic activity of allergens is usually prevented by the body’s own protease inhibitors, such as LEKTI, produced from the gene SPINK5.
• Lack of filaggrin gene causes dry skin. ^[1]

• Eczema can also be brought about by some adverse effects of medications.
• Below is a list of commonly prescribed medications with eczema as the common adverse drug effect (Table 1).

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1], Associate Editor(s)-in-Chief: Edzel Lorraine Co, DMD, MD[2]

Eczema has various mimics with regards to the clinical presentation, severity, and course of disease. A strong clinical evaluation by the physician based on the presenting signs and symptoms is needed to come up with the correct diagnosis. Differential diagnoses of eczema include infectious disease, inflammatory disease, immunodeficiency problem, or a nutritional deficiency.^[1]

A strong clinical evaluation by the physician based on the presenting signs and symptoms is needed to come up with the correct diagnosis.

• Table 1 summarizes these medical conditions that can mimic the presentation of eczema, with their corresponding expected time of onset.

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1], Associate Editor(s)-in-Chief: Edzel Lorraine Co, D.M.D., M.D.

In the United States, eczema has a prevalence of 10.7% in children and 7.2% in adults. ^{[1] [2]} Eczema has more predilection in males. ^[3]

• A recent study showed that persistence of disease 8 years from the onset is noted in 20% of children.^[4]
• Eczema has more predilection in males. ^[3]
• In the United States, eczema has a prevalence of 10.7% in children and 7.2% in adults. ^{[1] [2]}
• Prevalence of eczema has plateaued in high-income countries, with low- and middle-income countries still having increasing cases. ^[5]

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1], Associate Editor(s)-in-Chief: Edzel Lorraine Co, D.M.D., M.D.

Risk factors of eczema include family history and FLG gene mutation.

• Hereditary factors
  • Genetics is the strongest identifiable factor associated with development of eczema. ^[1]
  • Family history and FLG gene mutation. ^[2]
  • 34 genetic loci have been identified based on genome-wide association studies that accounts for almost 20% of eczema inheritance. ^[3]
  • The profilaggrin protein of the FLG gene maintains the intactness of the skin. ^[4]
  • Peanut allergy, herpes virus, and contact dermatitis were found to be associated with FLG gene mutation.^{[5] [6]}
• Environmental factors
  • People living in places with low humidity, cold temperature, and low ultraviolet light exposure tend to have a higher risk of eczema development according to US ecological records. ^[7]

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1], Associate Editor(s)-in-Chief: Edzel Lorraine Co, D.M.D., M.D.

Hanifin and Rajka criteria are the gold standard for diagnosing eczema. ^{[1] [2]}

• Hanifin and Rajka criteria are the gold standard for diagnosing eczema.
• It should satisfy 3 out of 4 major criteria or 3 out of 23 minor criteria. ^[3]

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1], Associate Editor(s)-in-Chief: Edzel Lorraine Co, D.M.D., M.D.

Eczema has regarded as a medical condition with a natural history that occurs consistently. It is characterized as a disease with an early onset, mostly during the childhood period, and remits during the adolescence period. If eczema is left untreated, it can lead to viral, bacterial and fungal infections. Psychological problems could also arise brought about by constant itching.

• Eczema has regarded as a medical condition with a natural history that occurs consistently.
• It is characterized as a disease with an early onset, mostly during the childhood period, and remits during the adolescence period. ^[1]

• Individuals suffering from eczema often have comorbidities like asthma ^[2], allergic rhinitis ^[3], contact dermatitis ^[4], food allergy, ^[5] and atopy-associated eye diseases.^[6]
  • Peanut allergy is the most common form of food allergy associated with eczema. ^[5]
  • The National Institute of Allergy and Infectious Diseases 2017 guidelines recommend that all infants suffering from severe eczema should undergo skin prick testing or peanut-specific IgE evaluation to assess for possible occurrence of peanut allergy and be prevented as early as possible. ^[7]
• Eczema is also associated with metabolic problems such as obesity. ^[8]

• Eczema can lead to viral, bacterial and fungal infections.
• Psychological problems could also arise brought about by constant itching.
  • 92,642 children participants with eczema in a cross-sectional study were observed to have a two-fold increase in having an attention deficit hyperactivity disorder (ADHD). ^{[9] [10]}
  • A higher incidence rate of anxiety disorders in adolescence is observed. These include generalized anxiety disorder and social anxiety disorder.
  • The elderly people with eczema are the most commonly affected with depression. ^[11]

• In those patients who have an onset of eczema during their first two years of life, a higher remission rate is expected than those who have a later onset of disease. ^[12]
• Hand eczema has poor prognosis with accounted 44% manifestation of symptoms in a 15-year follow-up study. ^[13]
• In another study, complete healing was only observed among 19.3% of the patients after a 5-year follow-up. ^[14]