psoriatic

A chronic skin disorder affecting 1% to 2% of the population, in which red papules and scaly silvery plaques with sharply defined borders appear on the body surface. The rash commonly is found on the knees, shins, elbows, umbilicus, lower back, buttocks, ears, and along the hairline. Pitting of the nails also occurs frequently. Patients complain of itching and sometimes of pain from dry, cracked, or encrusted lesions. Removal of scales usually causes fine bleeding points. Widespread shedding of scales is common, and occasionally the disease becomes pustular. The severity of the disease may range from a minimal cosmetic problem to total body surface involvement. About a third of all affected patients have a family history of the disease. psoriatic (sōr″ē-at′ik), adjective See: illustration

Although psoriasis may begin at any time of life, the most common age of onset is between 10 and 40. Sudden onset may occur related to HIV. The condition has relapses and partial remissions, but established lesions often persist for many months or years. Flare-ups may be related to specific systemic and environmental factors or may be unpredictable. About 5% of patients also develop an inflammatory arthritis (commonly affecting fingers and toes or sacroiliac joints), and patients with psoriasis have an increased rate of inflammatory bowel disease.

Etiology

Although the cause of psoriasis is unknown, some evidence suggests that immune dysregulation contributes to excessive proliferation of skin. Families with psoriasis have been found to have a significantly higher-than-normal incidence of certain human leukocyte antigens. Genetic studies show that about one third of affected patients have a family history of the disease. Emotional stress, skin trauma, cold weather, infections, and some drugs may trigger attacks.

Treatment

The disease has no cure, and all treatments are palliative. Topical corticosteroids, coal tar derivatives, vitamin D₃ analogs (e.g., calcipotriene), retinoids (e.g., etretinate, tacarotene), ultraviolet light exposure, and saltwater immersion are among the many methods that have been used effectively to treat this condition. For severe disease, immune-modulating drugs like methotrexate or cyclosporine sometimes are used, with close monitoring to prevent side effects.

CAUTION!

Many treatments for psoriasis carry some risk for the patient. Etretinate, for example, produces fetal abnormalities and should never be used by women of childbearing age. Phototherapy with ultraviolet light increases the risk of developing many types of skin cancer. Patients receiving PUVA therapy must wear goggles during treatments, stay out of the sun on treatment days, and protect their eyes with UVA-screening sunglasses for 24 hr after the therapy. Use of methotrexate use requires regular monitoring of liver function, renal function, complete blood counts, and lung function.

Patient care

The nurse teaches the patient about the prescribed therapy, to soften and remove scales, to relieve pruritus, to reduce pain and discomfort, to retard rapid cell proliferation, and to help induce remission and monitors for adverse reactions. Assistance is provided to help the patient gain confidence in managing these largely palliative treatments, many of which require special instructions for application and removal. The patient should protect against and minimize trauma. The patient's ability to manage therapies and their results are evaluated. The patient learns to identify stressors that exacerbate the condition, and to avoid and reduce these as much as possible. If the patient smokes cigarettes, participation in a smoking cessation program is recommended. The nurse helps the young patient (aged 20 to 30) to deal with body image changes and effects on self-esteem, encourages the patient to verbalize feelings, and supports the patient through loss of body image and associated grief. Psychological problems often occur. Referral for psychological counseling or cosmetic concealment therapy may be necessary. Patients and their families should be referred to the National Psoriasis Foundation and its local chapters for information and support. (800-723-9166; www.psoriasis.org)

Circular or ringlike lesions of psoriasis.

Leukoplakia of the oral mucosa.

A rare but persistent psoriasis that occurs on the back, thighs, and hips in thick scaling plaques.

Psoriasis characterized by small distinct lesions that generally occur over the body. The lesions appear particularly in the young after acute streptococcal infections. See: illustration

The most common form of psoriasis with disks and plaques of varying sizes on the extremities and trunk. There may be a great number of lesions or a solitary lesion.

Psoriasis in which small sterile pustules form, dry up, and then form a scab.

Psoriasis with hyperkeratotic lesions on the feet.

Severe generalized psoriasis.