People often use the terms atopic dermatitis and eczema interchangeably to refer to conditions that cause dryness, itchiness, rashes, and other skin lesions. While atopic dermatitis is a type of eczema, the term covers several different types of skin inflammation, such as contact dermatitis, discoid eczema, and dyshidrotic eczema.
Eczema refers to a group of conditions that cause the skin to become itchy, inflamed, or have a rash-like appearance. Evidence suggests that more than 31 million people in the United States are affected by eczema, with atopic dermatitis being the most common type.
This article defines eczema and atopic dermatitis and discusses other types of eczema, including how to identify, treat, and prevent them.
Both dermatitis and eczema are umbrella terms that people may use to refer to conditions that cause inflamed, irritated, and often itchy skin. There are many different types of eczema, such as neurodermatitis, stasis dermatitis, and atopic dermatitis (AD).
AD is a condition that makes the skin itchy and dry. The term atopic refers to being prone to developing an allergic hypersensitivity reaction to a trigger. AD is the most common type of eczema, which is why many people often simply call it eczema. Evidence suggests it affects roughly 1–3% of adults and 15–20% of children worldwide.
AD is a chronic skin condition that may come and go and currently has no cure. It has associations with other atopic conditions such as hay fever and asthma. In AD, a combination of genetic, immune system, and environmental factors likely cause the skin to experience inflammation against typically harmless substances in the environment.
Other types of eczema can include the below.
Like AD, asteatotic eczema, also known as eczema craquelé or xerotic eczema, has associations with dry skin. However, most skin lesions in asteatotic eczema are in the legs and look like plates of dry skin separated by cracks, showing a distinctive “dry riverbed” appearance. This type of eczema is typically more common in older adults, likely due to skin changes associated with aging.
AD and contact dermatitis go through the three stages of eczema and show similar features. However, with contact dermatitis, a person’s skin experiences irritation or an allergic reaction after contact with a trigger, causing the skin to sting, burn, and become inflamed.
There are many known potential irritants, including hair dyes, nickel, certain antibiotics, preservatives, and chemicals. There are two types of contact dermatitis: irritant and allergic contact dermatitis.
Discoid or nummular dermatitis
Similar to AD, discoid or nummular dermatitis is a long-term condition. It presents with similar symptoms of itchy patches of skin that may sometimes ooze fluid. However, in discoid dermatitis, skin patches have a distinct round shape.
Common triggers can include dry skin, insect bites, chemical burns, and other skin trauma. People with AD and allergic contact dermatitis are also prone to developing discoid eczema. A
Dyshidrotic eczema, which some health experts call pompholyx, causes small, itchy, and painful blisters to develop on the soles of the feet and palms of the hand.
Similar to AD, this condition tends to run in families. Dyshidrotic eczema is more common in adults aged under 40 years and females. Some people only have a single flare-up, but a majority can have it over the long term. Common triggers may include allergies, hot weather, moist hands, stress, and exposure to metals.
While AD and neurodermatitis can result in itchy lesions, skin thickening (lichenification), and discoloration, lesions in neurodermatitis are usually limited to one or two patches of skin. Itchy patches can develop anywhere but commonly appear on the feet, ankles, wrists, elbows, scalp, back of the neck, and groin area.
Neurodermatitis, which doctors call lichen simplex chronicus, develops when a person scratches an itchy skin patch. These lesions are often very itchy, while scratching may cause bleeding and scarring.
Seborrheic dermatitis affects skin areas that produce a lot of oil, including the scalp, nose, and upper back. The skin can appear swollen and greasy, while crusty scales may appear. The skin condition is due to an overproduction of Malassezia yeast, which causes an overreactive immune response, leading to skin inflammation.
It can occur in infants, known as cradle cap, and in adults. In infants, it often resolves by itself and does not come back. However, it often persists in adults and may come and go.
Varicose or stasis dermatitis
Also called stasis dermatitis, venous eczema, and gravitational dermatitis, this condition usually affects people with reduced circulation. While it is more common in older adults and women, it can also occur in young people with a predisposition to developing varicose veins. Aside from varicose veins, an individual with this skin disorder may notice ankle swelling and skin discoloration due to blood vessel bursting. It can also cause ulcers.
Since all eczema types commonly present with symptoms, such as skin dryness and inflammation, it can be challenging to differentiate. However, each type has its differences, which are below.
AD most often affects young children and infants, with the majority occurring in those aged 1 to 5 years of age. In contrast, other types may occur at any age but are typically more prevalent in adults.
Type of lesion
While most types have similarskin lesions, others have distinct characteristics. Discoid eczema has a distinctive round shape, while dyshidrotic eczema often comes with small, painful blisters. Contact dermatitis lesions typically appear in the area exposed to the irritant and have clear visible borders.
In infants and young children, AD lesions are typically present on the cheeks or the creases of elbows and knees, while adults often have AD around their eyes. Similarly, skin lesions in other types occur in other areas. Asteatotic and varicose eczemas have lower body lesions, dyshidrotic eczema affects the soles and palms, and seborrheic eczema most often affects the scalp.
Blood tests may reveal atypical immunoglobulin E levels for people with extrinsic AD, while these levels may be standard in other types of eczema. Patch testing can identify irritants in contact dermatitis, and doctors may detect reduced blood flow in people with varicose eczema.
AD often occurs with other atopic conditions. A 2021 review states asthma is a common comorbidity in people with AD. Additionally, individuals with varicose eczema have reduced circulation and may indicate heart and kidney problems.
Generally, avoiding triggers is the first step in treating eczema, while topical corticosteroids and emollients are usually first-line treatments. For more severe cases, doctors may prescribe stronger corticosteroids or oral steroids. People may also use wet wraps and over-the-counter medications, such as pain relievers and antihistamines, to help soothe symptoms.
While eczema currently has no cure, there are several ways to prevent or reduce flare-ups. These include:
- moisturizing and following proper skin care
- wearing loose clothing
- avoiding known irritants
- avoiding extreme temperatures
- taking regular lukewarm baths
Usually, most mild eczema cases are manageable. However, people who notice the following should speak with a doctor:
- worsening of symptoms
- pain and itching are affecting sleep and other activities
- lesions on new areas
Additionally, individuals should watch out for signs of infection, including:
- chills and fever
- weepy skin with clear or yellow fluid
- crust or spots on skin or eczema
- feeling unwell
Eczema is a common term for a group of conditions that cause skin irritation and inflammation. Atopic dermatitis is the most common type of eczema — many individuals often simply refer to it as eczema. However, there are several other types of eczema.
While they have similar symptoms and features, each type differs in its causes and progression. Being able to identify which type of eczema a person has is crucial for its prevention and treatment.