Your Guide to Understanding Eczema

What is Eczema?


Eczema is a chronic, inflammatory skin condition that is a result of an overactive immune system response to triggers inside or outside the body. It is a common condition that affects about 15% of the population and usually begins before the age of five. The specific cause of eczema remains unknown, but genes and environmental triggers are often linked to the development of eczema. General symptoms include red, itchy, dry, scaly, and inflamed skin. While eczema may seem scary, it is important to note that eczema is not contagious and cannot be spread by physical contact. In addition, while everyone who has eczema will have similar symptoms, conditions may vary based on the type of eczema they have.


The following are a list of the distinct types of eczema that exist:

  • Atopic dermatitis

  • Contact dermatitis

  • Dyshidrotic eczema

  • Nummular eczema

  • Seborrheic dermatitis

  • Stasis dermatitis


Atopic Dermatitis


The most common form of eczema, atopic dermatitis (AD) occurs when the immune system overreacts to an allergen or irritant inside or outside the body. Atopic dermatitis is part of the atopic triad, a group of allergic conditions, which includes both asthma and hay fever (also known as allergic rhinitis). Due to the close link between the three conditions, individuals who have one of the three, are more likely to develop the other conditions as well. Common symptoms of AD include dry, scaly skin, redness, itching, rashes on the cheeks, arms and/or legs, and open, crusted or “weepy” sores that may appear during flares. Symptoms tend to appear during the first six months of a baby’s life and may continue into adulthood or resolve with age, depending on the individual. While it is unknown, what may be the cause of AD, research shows that there is a correlation between individuals with AD and a genetic mutation of the filaggrin protein that is found in our skin. Filaggrin helps us maintain a healthy, protective skin barrier, so when it fails to function properly, moisture can escape and allow bacteria, viruses and more to enter the skin, compromising our skin barrier.


Contact Dermatitis


Contact dermatitis is a more environment-based type of eczema. It occurs when the skin comes into contact with irritating substances or allergens, which then causes the skin to become inflamed, itchy, and red. Other symptoms include having a localized burning sensation, swelling, rash, or blisters. Due to the nature of contact dermatitis’ triggers, flares usually will appear on the hands and other parts of the body that have touched the irritant/allergen. Common irritants include solvents, industrial chemicals, metals, fumes, paints, wool, some soaps and fragrances, and other environmental allergens.


Dyshidrotic Eczema


Dyshidrotic eczema is a type of eczema that is identified by small, itchy blisters that appear on the edges of the fingers, toes, palms, and soles of the feet. The blisters may persist for up to three weeks before they start to dry and resolve. As they dry, skin cracks may form with flaking observed. Dyshidrotic eczema more commonly appears in women and is often associated with seasonal allergies. Other triggers include stress, sweaty hands and feet, or exposure to nickel, cobalt, or chromium salts.


Nummular Eczema


Also known as discoid eczema and nummular dermatitis, nummular eczema presents differently than the other types of eczema. Individuals with nummular eczema develop coin-shaped lesions on the arms, legs, torso and/or hands that may or may not be itchy. The presentation and its effects on the individual also vary, with some individuals having dry and scaly spots, while others have wet and open spots. Some known triggers for nummular eczema include insect bites, reactions to skin inflammations elsewhere on the body, dry skin, and metals. Nummular eczema may also appear similar to a fungal infection and so it is important to check with your provider to rule out this possibility.


Seborrheic Dermatitis


Seborrheic dermatitis often appears where there are more oil-producing glands on the body, including the upper back, nose, and scalp. Symptoms range from dry flakes to yellow, greasy scales with reddened skin. Unlike other types of eczema, seborrheic dermatitis is not the result of an allergy. Seborrheic dermatitis is more often associated with genes and hormones that contribute to development. Some other common triggers include stress, compromised immune systems, harsh detergents, solvents, and soaps, cold, dry weather, and medications.


Stasis Dermatitis


Also known as gravitational dermatitis, venous eczema, and venous stasis dermatitis, stasis dermatitis occurs when there is a problem with blood circulation in the veins and pressure develops (often in the lower legs). The pressure causes fluid to leak out of the veins, into the skin, resulting in swelling of the ankles/lower legs, redness, scaling, dryness, itch, and varicose veins. In severe cases of stasis dermatitis, oozing, open wounds, and infection may be observed as well. Recurrent stasis dermatitis can result in scarring of the fat and soft tissues, as well as thickening of the skin due to chronic scratching or rubbing. Stasis dermatitis is often associated with other systemic conditions including high blood pressure, congestive heart failure, kidney failure, and blood clots in veins.


Navigating through the ins and outs of eczema may be confusing and scary at times. If you are experiencing any of the symptoms that are associated with eczema, contact your healthcare provider to receive an in-depth consultation on the exact type of eczema you have, your potential triggers, and available treatment options.


Weihong Zheng, M.D.