Psoriatic Arthritis

Psoriatic Arthritis

Key Points
Chronic, noncontagious, often lifelong skin condition affecting approximately 2- 3% of the population
Characterized by red, scaly , thickened plaques of the skin that may be located anywhere on the body, although the scalp, elbows and knees are probably the most commonly involved sites. The joints may be affected in up to 30% of patients
Tends to run in families
Psoriasis severity fluctuates on its own, but can be aggravated by environmental factors such as physical illness (especially infections), psychosocial stressors, and some medications
Psoriasis has a significant impact on quality of life
Like most diseases the exact cause is unknown, but psoriasis is characterized by rapid cell growth in the outer layer of skin (epidermis), which in turn is caused by increased activity of immune cells

Psoriasis is a fairly common skin condition, affecting 2-3% of the population. Affected persons will exhibit red, rough, sometimes quite thick patches of skin often covered with flaky silver skin (called scales).  These lesions may Itch. The nails may thicken and appear abnormal,and the genital area may be involved, especially in men. The joints, if affected, may be stiff and quite painful, and change the appearance of the small joints of the fingers or toes.. The severity of psoriasis is very variable, ranging from localized to total body involvement.

Psoriasis can develop at any age, but is generally first diagnosed in those patients between 15 and 25 years old. Almost 1/3 of those diagnosed have a relative who also suffers from the skin condition. Psoriasis affects men and women equally. While it can be brought on by many factors (immunologic, genetic, and environmental), certain medications can cause flare ups of the condition, including beta blockers, NSAIDS, lithium, antimalarials, and withdrawal from oral steroids.

Differential Diagnosis (Other conditions with similar appearance)
Pityriasis rubra pilaris
Secondary syphilis
Parapsoriasis
Lichen simplex
Nummular eczema
Lichen planus
Seborrheic dermatitis
Tinea corporis
Onychomycosis (fungal infection of the nails) if nails affected by psoriasis

Diagnosis
Key Points
Diagnosis based on skin appearance
Skin biopsy may be performed to rule out other conditions
In cases with joint pain, health care professionals may order x-rays or blood tests

Erythrodermic: Skin redness covers large areas, often the entire body
Guttate: Consists of large numbers of small pink/red spots
Inverse: Flare ups occur in the armpits, groin and anywhere skin overlaps or folds
Plaque: The most common type, consisting of the conventional red, scaly patches of skin
Pustular:  bright red and irritated skin upon which are many small white blisters (pustules)

Treatment
Most persons treated as outpatient, while severe cases may require hospitalization
Goal of treatment is to control symptoms and improve quality of life
In more severe cases, those diagnosed may be prescribed more aggressive therapies such as phototherapy (in the dermatologist’s office) or medications administered by mouth or injection (e.g. methotrexate or biologic medicines)
Antibiotics may be prescribed for those patients who experience a secondary infection

OTC (over the counter) options:  creams, lotions or ointments that contain coal tar, hydrocortisone, salicylic acid, lactic acid, dandruff shampoos, moisturizers

As most cases of psoriasis are mild to moderate, outpatient treatment is the generally accepted practice for controling psoriasis. Numerous topical medications are available by prescription.Oatmeal baths may soothe the affected areas. Exposure to a judicious amount (about 10 minutes) of mid-day sunlight can also help alleviate symptoms. Some sufferers undergo phototherapy treatment in the doctor’s office, controlled and careful exposure of the skin to ultraviolet light, which may given alone or with a drug which increases the skin's sensitivity to light.

Severe cases of psoriasis can require hospitalization, administration of pain management medications if the joints are swollen and painful, IV fluids and antibiotics to fight infection. Dermatologists may prescribe potent systemic (administered by mouth or injection) medicines such as methotrexate, acitretin, hydroxyurea, sulfasalazine, cyclosporine, or a new class of drugs called biologics (e.g. adalimumab, ustekinumab, eternacept, or Infliximab) if the severity of the skin or joint disease warrants the extra side effect risks of theses medicines. Many of these medications manipulate the function of the immune system and may expose the patient to a higher risk of serious infection.