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Chapters

0:00 Introduction
0:43 add more fruits and vegetables to your diet
1:06 be active
1:33 add more healthy fats to your diet
1:52 avoid physical injury
2:07 manage your stress
2:27 monitor nail changes
2:42 take medication as instructed
3:01 stay in touch with your health care tam




Psoriatic arthritis is a long-term inflammatory arthritis that occurs in people affected by the autoimmune disease psoriasis.[1][2] The classic feature of psoriatic arthritis is swelling of entire fingers and toes with a sausage-like appearance.[3] This often happens in association with changes to the nails such as small depressions in the nail (pitting), thickening of the nails, and detachment of the nail from the nailbed.[3] Skin changes consistent with psoriasis (e.g., red, scaly, and itchy plaques) frequently occur before the onset of psoriatic arthritis but psoriatic arthritis can precede the rash in 15% of affected individuals.[3] It is classified as a type of seronegative spondyloarthropathy.

Genetics are thought to be strongly involved in the development of psoriatic arthritis.[3] Obesity and certain forms of psoriasis are thought to increase the risk.[3]

Psoriatic arthritis affects up to 30% of people with psoriasis and occurs in both children and adults.[3] Approximately 40–50% of individuals with psoriatic arthritis have the HLA-B27 genotype.[3] The condition is less common in people of Asian or African descent and affects men and women equally.[3] Psoriasis is a long-lasting, noncontagious[4] autoimmune disease characterized by raised areas of abnormal skin.[5] These areas are red, or purple on some people with darker skin,[8] dry, itchy, and scaly.[3] Psoriasis varies in severity from small, localized patches to complete body coverage.[3] Injury to the skin can trigger psoriatic skin changes at that spot, which is known as the Koebner phenomenon.[9]

The five main types of psoriasis are plaque, guttate, inverse, pustular, and erythrodermic.[5] Plaque psoriasis, also known as psoriasis vulgaris, makes up about 90% of cases.[4] It typically presents as red patches with white scales on top.[4] Areas of the body most commonly affected are the back of the forearms, shins, navel area, and scalp.[4] Guttate psoriasis has drop-shaped lesions.[5] Pustular psoriasis presents as small, noninfectious, pus-filled blisters.[10] Inverse psoriasis forms red patches in skin folds.[5] Erythrodermic psoriasis occurs when the rash becomes very widespread, and can develop from any of the other types.[4] Fingernails and toenails are affected in most people with psoriasis at some point in time.[4] This may include pits in the nails or changes in nail color.[4]

Psoriasis is generally thought to be a genetic disease that is triggered by environmental factors.[3] If one twin has psoriasis, the other twin is three times more likely to be affected if the twins are identical than if they are nonidentical.[4] This suggests that genetic factors predispose to psoriasis.[4] Symptoms often worsen during winter and with certain medications, such as beta blockers or NSAIDs.[4] Infections and psychological stress can also play a role.[3][5] The underlying mechanism involves the immune system reacting to skin cells.[4] Diagnosis is typically based on the signs and symptoms.[4]