Localized scratch dermatitis

Also called neurodermatitis. A chronic, itchy inflammation of the skin that is more common between ages 30 and 50. It usually affects more women than men.

It's a result of chronic scratching of a skin area, which causes itching. This sets off more scratching, leading to a vicious circle called the itch-scratch cycle. The exact cause is unknown. Psychological factors could play a role.

The condition can happen anywhere on the skin, including the anus. Symptoms may include:

• Itching.
• Dryness and scaling.
• Darkened patches from rubbing.

Effective treatment usually includes stopping the scratching or rubbing. Other treatment may include:

• Antihistamines or topical medicines to control itching.
• Corticosteroid creams.
• Over-the-counter moisturizing creams.

Nummular dermatitis

A chronic rash that most commonly affects middle-aged people. It's more common in the winter and can last for months.

The cause is unknown. But it may be related to having dry skin or taking certain medicines.

With this condition there are round spots with small blisters, scabs, or scales. It can happen anywhere on the body. But it usually appears on the back of the arms and legs and on the buttocks. Other symptoms may include:

• Itchy areas of pimples.
• Dry skin.

Always see your doctor for a diagnosis.

Treatment depends on the person, as one treatment may not be right for everyone. Treatment may include:

• Moisturizers.
• Antibiotics.
• Corticosteroids.
• Ultraviolet light therapy.
• Protecting skin from injury.

Perioral dermatitis

A red, bumpy rash around the mouth and chin that usually affects women between the ages of 20 and 60.

The cause is unknown. But in some cases it may be related to the use of topical steroids.

Symptoms may include little blisters, skin scaling, and acne- or rosacea-like bumps around the mouth and at times around the eyes.

Treatment may include:

• Tetracyclines (antibiotics).
• Isotretinoin (acne medicine).
• Topical metronidazole or clindamycin or sodium sulfacetamide.
• Topical pimecrolimus.

Stasis dermatitis

A chronic inflammation of the lower legs caused by poor circulation. This leads to pooling of blood and fluid under the skin. The condition tends to affect people with varicose veins, heart failure, or other causes of swelling (edema). It's most often seen in the ankles and can spread up to the knees.

The skin may turn dark brown over time from this condition. Other symptoms may include:

• Red and scaly skin that is irritated.
• Swelling.
• Warm skin.
• Skin breakdown.
• Itchy skin.

The goal of treatment is to reduce the pooling of blood in the veins in the legs. Treatment may include:

• Raising (elevating) the legs.
• Wearing prescription compression stockings to prevent fluid buildup.
• Applying cool compresses.
• Keeping the skin clean to prevent infection.
• Corticosteroid creams.
• Antibiotics (if infection happens).
• Zinc oxide dressings.
• Skin grafts (if the skin develops large ulcers).
• Diuretics to reduce fluid in the legs.