Atopic dermatitis is a chronic form of dermatitis, found most commonly on the hands, feet, arms, legs, and scalp. No matter where you get it, it will itch badly. On lighter skinned people, the rash will start out red, unlike their darker-skinned counterparts; their rashes tend to affect the melanoma (coloring agent) in their skin, causing the spot to get lighter. It can grow and spread, but always remember that atopic dermatitis is not contagious. It’s most common in those that have other genetic or chronic illnesses, such as asthma, allergies, and hay fever.

Contact dermatitis is a rash one gets from coming in contact with something one is allergic to, or that will commonly irritate the skin. This includes poison ivy or oak, as well as different chemicals. The rash will appear either immediately, or within 12-36 hours after contact. This will itch just as badly as atopic dermatitis, but it isn’t chronic and will go away.

Another type of eczema is nummular dermatitis, also known as discoid eczema or dermatitis. These are coin-shaped (nummular, from the Latin “nummus” meaning “coin-shaped) itchy lesions that form on the skin, most commonly in those over 60, though they can appear at anytime. They can appear anywhere on the body, usually the hands, feet, arms, legs, and scalp, as with atopic dermatitis. While this is usually a treatable form of eczema, there is one subtype of nummular dermatitis that is resistant to treatment. This is called Sulzberger-Garbe Syndrome, or Oid-oid disease. Despite the silly name, Oid-oid disease is very difficult, so it’s kept under moderate control with various topical creams, though the lesions tend to resist all forms of medication.

Another type of dermatitis that is very common is psoriasis. Psoriasis is not technically eczema, but is commonly confused for it. It’s similar to atopic dermatitis, as it appears cutaneously (on the top layer of skin), and forms itchy red lesions. Unlike atopic dermatitis, psoriasis forms a white scaly layer over the rash. This is the main difference between the two. Keep in mind that both are treatable and neither are contagious.

All types of eczema are not communicable. They are all itchy rashy lesions that form usually on the hands, feet, arms, legs, and scalp, but could form anywhere. It can be chronic, like atopic and nummular dermatitis, or from coming in contact with a foreign substance, causing skin irritation. Talk to your doctor for further information and more information about seeking treatment for your or your loved ones’ eczema.