References:
- Brunner & Suddarth’s Textbook of Medical-Surgical Nursing, 15th Edition, ISBN 978-197-51-6103-3, by Janice L. Hinkle, Kerry H. Cheever, and Kristen J. Overbaugh (Ch. 13, pp. 4875–4883)
Psoriasis is a chronic noncommunicable inflammatory multisystem disorder of the skin and possible the oral cavity, eyes, and joints. Psoriasis is typically characterized by the appearance of silvery plaques that most commonly appear on the skin over the elbows, knees, scalp, lower back, and buttocks.
- Onset may occur at any age, with a median onset at 28 years.
- It is more prevalent among women and White Americans.
- It is thought that most patients with psoriasis have a genetic predisposition to develop the disease.
- Psoriasis is characterized by periods of remission and exacerbation throughout life.
Pathophysiology
Current evidence supports an autoimmune basis for psoriasis. Periods of emotional stress and anxiety aggravate the condition, and trauma, infections, and seasonal and hormonal changes may also serve as triggers.
- In this disease, the epidermis becomes infiltrated by activated T cells and cytokines, resulting in both vascular engorgement and proliferation of keratinocytes. Epidermal hyperplasia results.
- These epidermal cells tend to improperly retain their nuclei, crippling their ability to release lipids that encourage cellular adhesion.
- This results in rapid turnover of poorly matured cells that do not adhere well to each other, resulting in the classic presentation of plaquelike lesions that have a silvery, scaly, and flaky appearance.
Complications
- Asymmetric rheumatoid factor—negative arthritis (psoriatic arthritis) of multiple joints occurs in up to 42% of people with psoriasis, most typically after the skin lesions appear. This most typically affects joints in the hands or feet, although sometimes larger joints such as the elbows, knees, or hips may be affected. A rheumatologist should be consulted to assist in the diagnosis and long-term treatment of this disorder.
- Generalized exfoliative dermatitis may also result from psoriasis.
Clinical Manifestations
Psoriasis may range in severity from a cosmetic source of annoyance to a physically disabling and disfiguring disorder. Lesions appear as red, raised patches of skin covered with silvery scales. The scaly patches are formed by the buildup of living and dead skin.
- If scraped off, the dark red base of the lesion is exposed, producing multiple bleeding points.
- The patches are not moist and may be pruritic.
- In many cases, the nails are also involved, with pitting, discoloration, crumbling beneath the free edges, and separation of the nail plate.
A classification of mild is given for less than 5% body surface area involvement, moderate for 5%–10% of BSA, and severe if >10% is affected by plaque formation.
The presence of the classic plaque-type lesions generally confirms the diagnosis of psoriasis. If in doubt, the health care provider should assess for signs of nail and scalp involvement and for a positive family history. Biopsy of the skin is of little diagnostic value. The presence and extent of plaque should be assessed carefully, to calculate BSA involvement.
Medical Management
The goals of management are to slow the rapid turnover of epidermis, to promote resolution of the psoriatic lesions, and to control the natural cycles of the disease. There is no known cure.
Pharmacologic Therapy
Three types of therapy are commonly indicated: topical, phototherapy, and systemic. Topical agents, possibly in tandem with phototherapy, are recommended for mild disease. Patients with moderate or severe disease should receive topical agents, phototherapy, and systemic treatment
- Topical Agents: Topically applied agents are used to slow the overactive epidermis.
- Topical corticosteroids may be applied for their anti-inflammatory effects.
- Phototherapy:
- Systemic Agents: