How is Psoriatic Arthritis Linked to Psoriasis?
Psoriatic arthritis (PsA) occurs in up to 40% of people with psoriasis. Both are chronic, inflammatory diseases. Generally, skin symptoms precede the joint symptoms, however in about 10-15% of cases, PsA develops before psoriasis.1,2
Psoriasis is a chronic skin condition that affects an estimated 2% of the U.S. adult population. Both men and women develop psoriasis at equal rates. Psoriasis can occur at any age, but the most likely age of onset is between 15 and 30 years. 3About 10-15% of people with psoriasis develop it before age 10.4
Risk factors for psoriasis
Approximately one-third of people with psoriasis have a first-degree relative with the condition. While the direct cause is unknown, genetics and the immune system seem to play a role in its development. Generally, an environmental factor triggers the condition to flare.
Common triggers are infections, stress, and trauma to the skin.3Smoking increases the risk of psoriasis and negatively affects its severity. Obesity and alcohol use and abuse are also associated with psoriasis.
It isn’t known if these lifestyle factors are causative or if people with psoriasis are more likely to have smoked and used alcohol as a way of coping with their highly visible and stigmatized skin symptoms.3
Characteristics of psoriasis
Psoriasis occurs in several forms, with about 80% of people having plaque psoriasis. Plaque psoriasis causes round or oval red patches on the skin that are scaly, itchy, and painful.
The lesions of plaque psoriasis often occur on the arms, legs, scalp, buttocks, and trunk. Less common types of psoriasis include:
- Inverse psoriasis, which occurs in skin folds
- Erythrodermic psoriasis, which is characterized by wide-spread redness and has systemic symptoms
- Pustular psoriasis, which causes pustules on the palms of the hands and soles of the feet
- Guttate psoriasis, which is more common in younger individuals and presents with small red lesions with fine scaling3
The impact of psoriasis
Psoriasis is a persistent, long-lasting chronic condition. Due to its painful symptoms and distressing appearance, psoriasis causes significant emotional distress.
In one survey, 79% of people with psoriasis said the disease negatively impacted their lives, causing problems with work, activities of daily living, and socialization. The majority of people surveyed felt unattractive, and more than half were depressed.3
Treatment for psoriasis
There is no known cure for psoriasis, and the goals of treatment include improvement of skin, nail, and joint lesions plus an improvement in quality of life. Treatment options are based on the severity of the disease, which is generally determined by the surface area of the body affected by the disease.
The National Psoriasis Foundation has also suggested the impairment to quality of life should be incorporated into the decision, and people with psoriasis who have a more significant impact on their quality of life are more willing to accept life-altering side effects with treatment.3,4
Mild to moderate disease can often be treated successfully with topical therapies, such as corticosteroids, vitamin D analogs, tazarotene (Tazorac) and calcineurin inhibitors.
Severe disease (that which involves more than 5% of the body surface area) is generally treated with light therapy in combination with systemic treatment. Systemic treatments include methotrexate, cyclosporine (Sandimmune), acitretin (Soriatane), and biologic therapies.3