About eczema (atopic dermatitis)
Atopic dermatitis is commonly known as eczema. The term eczema is non-specific and refers to the nature of the skin lesion and not a specific skin disorder. Many rashes are described as “eczematous” Here we will discuss atopic dermatis. This is a chronic dermatitis associated with a family or personal history of “atopic disease”, which includes asthma, allergic rhinitis, or atopic dermatitis. It is primarily a disease of childhood, but many still suffer into adulthood. Atopic dermatitis is thought to arise from a combination of genetic susceptibility and extrinsic factors. As with other eczematous conditions, pruritus (itching) is a salient feature. The morphology of the rash as well as its distribution are dependent on age. Infantile atopic dermatitis exhibits the lesions of an acute dermatitis: papules and vesicles with oozing, weeping and crusting. It is located on the head, diaper area and extensor surfaces of the extremities. In children and adults the rash favors the flexor surfaces of extremities (i.e. the antecubital and popliteal fossae), as well as the neck, face and upper chest. Chronic atopic dermatitis appears as lichenification (thickening of the skin with accentuated skin markings). Atopic individuals often have infraorbital creases called Dennie-Morgan lines.
With what can atopic dermatitis be confused?
Atopic dermatitis must be differentiated from other causes of dermatitis, as well as scabies. During infancy it is important to rule out the diseases Wiskott Aldrich syndrome (X-linked Recessive) and Hyper IgE Syndrome (Autosomal Dominant), which are both associated with cutaneous findings nearly identical to atopic dermatitis, but also have other associated signs and symptoms that would usually be noted.
How is atopic dermatitis diagnosed?
The diagnosis is made clinically based on the patient’s age and the typical appearance and distribution of lesions. Allergic respiratory disease (e.g. allergic asthma, seasonal allergies) is often present in patients or their family members. Biopsy is typically not necessary.
How is atopic dermatitis treated?
Stop itch/scratch cycle
It is important to disrupt the itch/scratch cycle.
Avoid triggers
Avoidance of environmental triggers, such as wool clothing, harsh soaps and detergents, known food allergies, and emotional and environmental triggers is important in this regard. Food allergies, especially to eggs, wheat, milk, and peanuts have been implicated in atopic dermatitis. Skin testing, followed by confirmatory challenge and elimination diets, may be beneficial but frequently is not. Moisturizers decease dry skin and reduce pruritus and are very helpful in breaking the itch/scratch cycle.
Corticosteroids
Corticosteroids are the mainstay of medical treatment. Typical topical preparations, in order of increasing potency, are hydrocortisone 1%, triamcinolone 0.1%, and fluocinonide 0.05%. Widespread dermatitis is best treated with short term oral steroids (e.g. prednisone).
Other topical treatments
Symptoms of widespread dermatitis can be treated with baths, with or without additives such as colloidal oatmeal (e.g. Aveeno) or tar (e.g. Cutar). Astringent dressings (e.g. Domeboro) are also beneficial.
Antihistamines
Pruritus can be relived with antihistamines such as hydroxyzine or diphenhydramine.
Antibiotics
Antibiotics (anti-Staph spectrum) are required in the event of secondary infection. Persons with atopic dermatitis often are heavily colonized with staph species. Flares often respond to antibiotics. Bleach baths (1 cap of bleach in a tub of water) can help reduce bacterial colonization.
Tacrolimus and Pimecrolimus for eczema
The immune modulators, such as tacrolimus, are especially useful on the face, since they do not have the skin thinning and neo-vascularizing side-effects of topical corticosteroids. They are also good for long-term use and maintenance.
Opzelura and other JAK inhibitors
A new class of medications, the JAK inhibitors, are recently approved for eczema and other indications. Opzeulra is indicated for short-term and non-continuous chronic treatment of mild to moderate eczema in non-immunocompromised adults and children 12 years of age and older whose disease is not well controlled with topical prescription therapies or when those therapies are not recommended
Light Therapy
Psoralen plus ultraviolet radiation (PUVA), or ultraviolet B radiation (UVB) are second-line therapies but can be very helpful.
Dupixent and Adbry
Dupixent, a novel biologic agent, is used to treat atopic dermatitis. More recently ADBRY (tralokinumab-ldrm) has been approved; this drug targets IL-13.
Other Immunosupressants
If all else fails, systemic therapy with cyclosporine or azathioprine may help.
What is the prognosis for atopic dermatitis?
Atopic dermatitis is marked by acute flares and periods of slow resolution. Most children outgrow the disease by adolescence, but many continue to have more circumscribed dermatitis. Secondary infection of the skin, due to breakdown of the epidermal barrier and decreased cellular immunity, is common.
