Skin rashes are extremely common and can have many causes. If you have a skin rash and aren’t sure what it is, it’s best to talk to a board-certified dermatologist who can give you the right diagnosis and treatment. The most common skin rashes are caused by psoriasis and eczematous dermatitis, and while they can be uncomfortable, there are many treatments that can help.
What Is Atopic Dermatitis?
Eczematous dermatitis refers to a specific type of reaction rather than a single condition. Eczema, which is also called atopic dermatitis, is the most common cause of eczematous dermatitis. It occurs when the immune system overreacts to irritants or allergens, such as environmental allergens or harsh laundry detergents. While the cause is not fully understood, atopic dermatitis is known to be more common in families with a history of allergies.
What Is Psoriasis?
New skin normally grows in a predictable pattern and at a steady rate, but in people with psoriasis, the cells grow faster than normal due to inflammation underneath, building up on top of the skin rather than shedding. The extra cells leave red, scaly patches called plaques. Plaques can occur anywhere on your body but are most common on the scalp, elbows and knees. In some cases, it can affect your joints, too. When this happens, it is called psoriatic arthritis.
Symptoms of eczematous dermatitis tend to have similar symptoms, including:
- Inflamed, irritated skin
- Itchy skin
- Occasionally fluid-filled blisters on the hands and/or feet
- Dryness and peeling
- Skin fissures
If you have psoriasis, your symptoms can vary depending on what type of psoriasis you have. However, most people have plaque psoriasis, which causes:
- Itching and burning sensations
- Inflamed skin
- Raised patches with thick, white, scaly skin
Guttate psoriasis can cause small red or pink spots. Inverse psoriasis causes smooth, shiny patches of skin in the body folds. Pustular psoriasis can include pustules all over the body in severe cases.
Eczema vs. Psoriasis
Psoriasis rarely affects the face, but those with scalp psoriasis might find it spreading to their ears, neck or forehead. Eczematous dermatitis can affect the face, causing itching, dryness, cracked skin and redness.
Psoriasis commonly affects the hands, especially the palms. Some people can also develop psoriasis under their fingernails as well, creating a thickened or discolored appearance. In severe cases, the nails might fall off. Eczematous dermatitis is also common on the hands, possibly because hands are so often in contact with irritating substances.
Psoriasis can affect the entire arms and legs or just the elbow and knee. Eczematous dermatitis is more likely to affect the creases of the arms and legs, such as the inside of the elbow or the backs of the knees where sweat and friction make symptoms worse.
Both conditions can be widespread and persistent, and both can be both itchy and painful. Damage to the skin, such as through a crack or fissure, can increase the risk of infection.
Neither eczematous dermatitis or psoriasis is curable, but treatments are available. If you have eczema, your dermatologist can work with you to spot triggers and may prescribe a corticosteroid to reduce redness and soothe itching. Barrier lotions or creams can protect your skin from further harm. You might need an antibiotic if your skin becomes infected. Over-the-counter treatments are also available, but it’s best to have an accurate diagnosis and the right treatment plan to get the most relief.
Psoriasis can also be treated using corticosteroid creams or ointments. Light therapy and systemic oral or injectable treatments are also commonly used and highly effective. A barrier lotion can protect skin from further damage.
Skin rashes can be caused by atopic dermatitis, psoriasis or other conditions. Any rash should be checked out by a dermatologist to make sure it’s not caused by something serious. Your dermatologist can also help you find the right treatment protocol for your skin needs.