Psoriasis is a chronic skin disease that affects more than five million Americans. It can occur at any age including infancy and childhood. Psoriasis is not contagious. The rash of psoriasis is often found on the knees, elbows, scalp, hands and feet, although it can occur anywhere on the skin.

Psoriasis can be limited to a few lesions or it can involve larger areas of skin. It affects each person differently. Some people with psoriasis may also develop arthritis, which results in painful or swollen joints.

Types of Psoriasis

There are several forms of psoriasis:

• Plaque psoriasis: Red, scaly areas on the arms, legs, chest, back, abdomen and scalp
• Guttate psoriasis: Small, red, scaly, dot-like bumps; very common in children
• Pustular psoriasis: Redness of the skin with pustules
• Inverse psoriasis: Red areas in the creases of the body, such as the underarms and groin
• Erythrodermic psoriasis: Intense redness and peeling of the skin of the entire body

Causes of Psoriasis

No one knows exactly what causes psoriasis. Genetics plays a role, and children with psoriasis often have a parent or other family member with psoriasis. The immune system is also involved in psoriasis. It is believed that the immune system becomes overactive, speeding up the growth cycle of skin cells. The rapid production of skin cells and inflammation in the skin cause the rash. In children, psoriasis is often triggered by a recent infection with streptococcus. Stress and illness can trigger psoriasis or make it worse.

Treatment

There is no cure for psoriasis. There are many types of treatments that the doctor can prescribe. These include both topical (on the skin) and systemic (throughout the body) treatments. Often, people with psoriasis need to try different treatments before they find the ones that work for them.

It is very important that you keep your follow-up appointments so that the doctor may check to see if your child is having side effects from the treatment. The doctor may also change the treatment.

Your doctor may prescribe one or several medications. Types of medications used to treat psoriasis include topical medications, phototherapy or systemic medications. Follow the instructions carefully. Your doctor may prescribe different medications for different parts of the body or for use on different days. If your child has had a recent infection with streptococcus, use of an oral antibiotic may also be recommended.

• Topical medications − include moisturizers, topical steroids, topical vitamin D (calcipotriene), topical vitamin A (retinoid) and tar.
• Phototherapy − a type of ultraviolet light therapy that is given in a special booth. It is available only through a dermatologist. It is very important that you keep your phototherapy appointments. You must limit your child’s exposure to sunlight when he or she is getting phototherapy, as your child is more likely to get a sunburn. Don’t forget to apply sunscreen.
• Systemic medication − such as etanercept (Enbrel) injections, isotretinoin (Accutane), methotrexate or cyclosporine may be recommended. It is extremely important that you take these medications exactly as prescribed. Frequent blood tests may be required and are very important. If your child does not get the blood tests, the medication may need to be stopped. Also, these medications may make your child more likely to get sick with an infection.

When to Call the Doctor

• If you child is not improving on the prescribed treatment or if his or her psoriasis suddenly gets much worse
• If your child develops a fever or appears ill while on systemic therapy such as methotrexate, cyclosporine or etanercept