Psoriatic arthritis
Encyclopedia
Psoriatic arthritis is a type of inflammatory
arthritis
that, according to the National Psoriasis Foundation
, will develop in up to 30 percent of people who have the chronic skin condition psoriasis
. Psoriatic arthritis is said to be a seronegative
spondyloarthropathy
and therefore occurs more commonly in patients with tissue type HLA-B27
.
Psoriatic arthritis may remain mild, or may progress to more destructive joint disease. Periods of active disease, or flares, will typically alternate with periods of remission.
Because prolonged inflammation can lead to joint damage, early diagnosis and treatment to slow or prevent joint damage is recommended
. A rheumatologist (a doctor specializing in diseases affecting the joints) may use physical examinations, health history, blood tests and x-rays to accurately diagnose psoriatic arthritis.
Factors that contribute to a diagnosis of psoriatic arthritis include:
Other symptoms that are more typical of psoriatic arthritis than other forms of arthritis include inflammation in the Achilles tendon
(at the back of the heel) or the Plantar fascia
(bottom of the feet), and dactylitis
(sausage-like swelling of the fingers or toes).
, therefore treatments are directed at reducing and controlling inflammation
. Milder cases of psoriatic arthitis may be treated with NSAIDS alone; however there is a trend toward earlier use of Disease-modifying antirheumatic drug
s or biological response modifiers to prevent irreversible joint destruction.
and naproxen
followed by more potent NSAIDs like diclofenac
, indomethacin, and etodolac
. NSAIDs can irritate the stomach and intestine, and long-term use can lead to gastrointestinal bleeding. Other potential adverse effects include damage to the kidneys and cardiovascular system.
or leflunomide
are commonly prescribed; other DMARDS used to treat psoriatic arthritis include ciclosporin
, azathioprine
and sulfasalazine. These immunosuppressant
drugs can also reduce psoriasis skin symptoms, but can lead to liver and kidney problems and an increased risk of serious infection.
or biologics has been developed using recombinant DNA
technology. Biologic medications are derived from living cells cultured in a laboratory. Different from the traditional DMARDS that impact the entire immune system, biologics target specific parts of the immune system. They are given by injection or intravenous (IV) infusion.
Biologics prescribed for psoriatic arthritis are TNF-α inhibitors, including infliximab
, etanercept
, golimumab
, certolizumab pegol
and adalimumab
.
Biologics may increase the risk of both minor and serious infections. More rarely, they may be associated with nervous system disorders, blood disorders or certain types of cancer.
s with corticosteroid
s in cases where one joint is severely impacted. In psoriatic arthritis patients with severe joint damage orthopedic surgery
may be implemented to correct joint destruction, usually with use of a joint replacement
. Surgery is effective for pain alleviation, correcting joint disfigurement, and reinforcing joint usefulness and strength.
Maintaining a healthy weight places less strain on the joints, leading to reduced pain and increased energy and mobility.
Regular exercise is recommended for people with arthritis to help maintain flexibility and strength. Biking, swimming and walking are commonly recommended.
Hot and cold packs can relieve inflamed joints. Cold has a numbing effect and can dull the sensation of pain. Heat can help relax tense muscles and relieve pain.
on the skin, 15 percent develop skin psoriasis and arthritis at the same time, and 15 percent develop skin psoriasis following the onset of psoriatic arthritis.
Psoriatic arthritis can develop in people who have any level severity of psoriatic skin disease from mild to very severe.
Psoriatic arthritis tends to appear about 10 years after the first signs of psoriasis
. For the majority of people this is between the ages of 30 and 55, but the disease can also affect children. The onset of psoriatic arthritis symptoms before symptoms of skin psoriasis is more common in children than adults.
More than 80% of patients with psoriatic arthritis will have psoriatic nail lesions characterized by nail pitting, separation of the nail from the underlying nail bed, ridging and cracking, or more extremely, loss of the nail itself (onycholysis
).
Men and women are equally affected by this condition. Like psoriasis
, psoriatic arthritis is more common among Caucasians than African or Asian Americans.
Inflammation
Inflammation is part of the complex biological response of vascular tissues to harmful stimuli, such as pathogens, damaged cells, or irritants. Inflammation is a protective attempt by the organism to remove the injurious stimuli and to initiate the healing process...
arthritis
Arthritis
Arthritis is a form of joint disorder that involves inflammation of one or more joints....
that, according to the National Psoriasis Foundation
National Psoriasis Foundation
The National Psoriasis Foundation is the United States’ leading patient-driven, nonprofit advocacy organization that serves the estimated 7.5 million Americans affected by psoriasis and psoriatic arthritis....
, will develop in up to 30 percent of people who have the chronic skin condition psoriasis
Psoriasis
Psoriasis is an autoimmune disease that appears on the skin. It occurs when the immune system mistakes the skin cells as a pathogen, and sends out faulty signals that speed up the growth cycle of skin cells. Psoriasis is not contagious. However, psoriasis has been linked to an increased risk of...
. Psoriatic arthritis is said to be a seronegative
Seronegative arthritis
A seronegative arthritis is an arthritis that is distinguished from rheumatoid arthritis due the absence of rheumatoid factor .-Contrasting with rheumatoid arthritis:...
spondyloarthropathy
Spondyloarthropathy
Spondyloarthropathy is any joint disease of the vertebral column. Spondyloarthropathy with inflammation is called spondylarthritis. In contrast, spondylopathy is a disease of the vertebra itself, but many conditions involve both spondylopathy and spondyloarthropathy...
and therefore occurs more commonly in patients with tissue type HLA-B27
HLA-B27
Human Leukocyte Antigen B27 is a class I surface antigen encoded by the B locus in the major histocompatibility complex on chromosome 6 and presents antigenic peptides to T cells...
.
Signs and symptoms
Common symptoms of psoriatic arthritis include:- Pain, swelling, or stiffness in one or more joints.
- Joints that are red or warm to the touch.
- Sausage-like swelling in the fingers or toes, known as dactylitisDactylitisDactylitis or sausage digit is inflammation of an entire digit , and can be painful.The word dactyl comes from the Greek word "daktylos" meaning "finger"...
. - Pain in and around the feet and ankles, especially tendinitis in the Achilles tendon or Plantar fasciitisPlantar fasciitisPlantar fasciitis is a painful inflammatory process of the plantar fascia, the connective tissue on the sole of the foot.Longstanding cases of plantar fasciitis often demonstrate more degenerative changes than inflammatory changes, in which case they are termed plantar fasciosis. The suffix...
in the sole of the foot. - Changes to the nails, such as pitting or separation from the nail bed.
- Pain in the area of the SacrumSacrumIn vertebrate anatomy the sacrum is a large, triangular bone at the base of the spine and at the upper and back part of the pelvic cavity, where it is inserted like a wedge between the two hip bones. Its upper part connects with the last lumbar vertebra, and bottom part with the coccyx...
(the lower back, above the tailbone).
Psoriatic arthritis may remain mild, or may progress to more destructive joint disease. Periods of active disease, or flares, will typically alternate with periods of remission.
Because prolonged inflammation can lead to joint damage, early diagnosis and treatment to slow or prevent joint damage is recommended
Causes
The exact causes are not yet known, but a number of genetic associations have been identified in a genome-wide association study of psoriasis and psoriatic arthritis including HLA-B27.Diagnosis
There is no definitive test to diagnose psoriatic arthritis. Symptoms of psoriatic arthritis may closely resemble other diseases, including rheumatoid arthritisRheumatoid arthritis
Rheumatoid arthritis is a chronic, systemic inflammatory disorder that may affect many tissues and organs, but principally attacks synovial joints. The process produces an inflammatory response of the synovium secondary to hyperplasia of synovial cells, excess synovial fluid, and the development...
. A rheumatologist (a doctor specializing in diseases affecting the joints) may use physical examinations, health history, blood tests and x-rays to accurately diagnose psoriatic arthritis.
Factors that contribute to a diagnosis of psoriatic arthritis include:
- Psoriasis in the patient, or a family history of psoriasis or psoriatic arthritis.
- A negative test result for Rheumatoid factorRheumatoid factorRheumatoid factor is an autoantibody most relevant in rheumatoid arthritis. It is defined as an antibody against the Fc portion of IgG. RF and IgG join to form immune complexes that contribute to the disease process...
, a blood factor associated with rheumatoid arthritis. - Arthritis symptoms in the distal Interphalangeal articulations of hand (the joints closest to the tips of the fingers). This is not typical of rheumatoid arthritis.
- Ridging or pitting of fingernails or toenails (onycholysisOnycholysisOnycholysis refers to the detachment of the nail from the nail bed, starting at its distal and/or lateral attachment. It is said to occur particularly on the ring finger but can occur on any of the fingernails. The most common cause of onycholysis is psoriasis. It can also occur in thyrotoxicosis...
), which is associated with psoriasis and psoriatic arthritis. - Radiologic images indicating joint change.
Other symptoms that are more typical of psoriatic arthritis than other forms of arthritis include inflammation in the Achilles tendon
Achilles tendon
The Achilles tendon , also known as the calcaneal tendon or the tendo calcaneus, is a tendon of the posterior leg. It serves to attach the plantaris, gastrocnemius and soleus muscles to the calcaneus bone.- Anatomy :The Achilles is the tendonous extension of 3 muscles in the lower leg:...
(at the back of the heel) or the Plantar fascia
Plantar fascia
The plantar fascia is the thick connective tissue which supports the arch on the bottom of the foot. It runs from the tuberosity of the calcaneus forward to the heads of the metatarsal bones .The often painful condition plantar fasciitis is an inflammatory condition of the plantar...
(bottom of the feet), and dactylitis
Dactylitis
Dactylitis or sausage digit is inflammation of an entire digit , and can be painful.The word dactyl comes from the Greek word "daktylos" meaning "finger"...
(sausage-like swelling of the fingers or toes).
Classification
There are five main types of psoriatic arthritis:- Asymmetric: This type affects around 70% of patients and is generally mild. This type does not occur in the same joints on both sides of the body and usually only involves fewer than 3 joints.
- Symmetric: This type accounts for around 25% of cases, and affects joints on both sides of the body simultaneously. This type is most similar to rheumatoid arthritisRheumatoid arthritisRheumatoid arthritis is a chronic, systemic inflammatory disorder that may affect many tissues and organs, but principally attacks synovial joints. The process produces an inflammatory response of the synovium secondary to hyperplasia of synovial cells, excess synovial fluid, and the development...
and is disabling in around 50% of all cases.
- Arthritis mutilans : Affects less than 5% of patients and is a severe, deforming and destructive arthritis. This condition can progress over months or years causing severe joint damage. Arthritis mutilans has also be called chronic absorptive arthritis, and may be seen in rheumatoid arthritisRheumatoid arthritisRheumatoid arthritis is a chronic, systemic inflammatory disorder that may affect many tissues and organs, but principally attacks synovial joints. The process produces an inflammatory response of the synovium secondary to hyperplasia of synovial cells, excess synovial fluid, and the development...
as well.
- Spondylitis : This type is characterised by stiffness of the spine or neck, but can also affect the hands and feet, in a similar fashion to symmetric arthritis.
- Distal interphalangeal predominant : This type of psoriatic arthritis is found in about 5% of patients, and is characterised by inflammation and stiffness in the joints nearest to the ends of the fingers and toes. Nail changes are often marked.
Treatments
The underlying process in psoriatic arthritis is inflammationInflammation
Inflammation is part of the complex biological response of vascular tissues to harmful stimuli, such as pathogens, damaged cells, or irritants. Inflammation is a protective attempt by the organism to remove the injurious stimuli and to initiate the healing process...
, therefore treatments are directed at reducing and controlling inflammation
Inflammation
Inflammation is part of the complex biological response of vascular tissues to harmful stimuli, such as pathogens, damaged cells, or irritants. Inflammation is a protective attempt by the organism to remove the injurious stimuli and to initiate the healing process...
. Milder cases of psoriatic arthitis may be treated with NSAIDS alone; however there is a trend toward earlier use of Disease-modifying antirheumatic drug
Disease-modifying antirheumatic drug
Disease-modifying antirheumatic drugs is a category of otherwise unrelated drugs defined by their use in rheumatoid arthritis to slow down disease progression...
s or biological response modifiers to prevent irreversible joint destruction.
Nonsteroidal anti-inflammatory drugs
Typically the medications first prescribed for psoriatic arthritis are NSAIDs such as ibuprofenIbuprofen
Ibuprofen is a nonsteroidal anti-inflammatory drug used for relief of symptoms of arthritis, fever, as an analgesic , especially where there is an inflammatory component, and dysmenorrhea....
and naproxen
Naproxen
Naproxen sodium is a nonsteroidal anti-inflammatory drug commonly used for the reduction of pain, fever, inflammation and stiffness caused by conditions such as:...
followed by more potent NSAIDs like diclofenac
Diclofenac
Diclofenac is a non-steroidal anti-inflammatory drug taken to reduce inflammation and as an analgesic reducing pain in certain conditions....
, indomethacin, and etodolac
Etodolac
Etodolac: Etodolac belongs to a class of drugs called nonsteroidal anti-inflammatory drugs . Other members of this class include aspirin, ibuprofen , naproxen , indomethacin , nabumetone and numerous others. These drugs are used for the management of mild to moderate pain, fever, and inflammation...
. NSAIDs can irritate the stomach and intestine, and long-term use can lead to gastrointestinal bleeding. Other potential adverse effects include damage to the kidneys and cardiovascular system.
Disease-modifying antirheumatic drugs
Rather than just reducing pain and inflammation, this class of drugs helps limit the amount of joint damage that occurs in psoriatic arthritis. Most DMARDs act slowly, and may take weeks or even months to take full effect. Drugs such as methotrexateMethotrexate
Methotrexate , abbreviated MTX and formerly known as amethopterin, is an antimetabolite and antifolate drug. It is used in treatment of cancer, autoimmune diseases, ectopic pregnancy, and for the induction of medical abortions. It acts by inhibiting the metabolism of folic acid. Methotrexate...
or leflunomide
Leflunomide
Leflunomide is a medication of the DMARD type, used in active moderate to severe rheumatoid arthritis and psoriatic arthritis. It is a pyrimidine synthesis inhibitor.-Basic chemical, pharmacological, and marketing data:...
are commonly prescribed; other DMARDS used to treat psoriatic arthritis include ciclosporin
Ciclosporin
Ciclosporin , cyclosporine , cyclosporin , or cyclosporin A is an immunosuppressant drug widely used in post-allogeneic organ transplant to reduce the activity of the immune system, and therefore the risk of organ rejection...
, azathioprine
Azathioprine
Azathioprine is a purine analogue immunosuppressive drug. It is used to prevent organ rejection following organ transplantation and to treat a vast array of autoimmune diseases, including rheumatoid arthritis, pemphigus, inflammatory bowel disease , multiple sclerosis, autoimmune hepatitis, atopic...
and sulfasalazine. These immunosuppressant
Immunosuppressant
An immunosuppressant is any substance that performs immunosuppression of the immune system. They may be either exogenous, as immunosuppressive drugs, or endogenous, as ,e. g., testosterone...
drugs can also reduce psoriasis skin symptoms, but can lead to liver and kidney problems and an increased risk of serious infection.
Biological response modifiers
Recently, a new class of therapeutics called biological response modifiersBiological response modifiers
Biological response modifiers, also known as BRM's, are substances that the human body produces naturally, as well as something that scientists can create in a lab. These substances arouse the body's response to an infection. Some of these are used to treat arthritis, cancer, and some other...
or biologics has been developed using recombinant DNA
Recombinant DNA
Recombinant DNA molecules are DNA sequences that result from the use of laboratory methods to bring together genetic material from multiple sources, creating sequences that would not otherwise be found in biological organisms...
technology. Biologic medications are derived from living cells cultured in a laboratory. Different from the traditional DMARDS that impact the entire immune system, biologics target specific parts of the immune system. They are given by injection or intravenous (IV) infusion.
Biologics prescribed for psoriatic arthritis are TNF-α inhibitors, including infliximab
Infliximab
Infliximab is a monoclonal antibody against tumour necrosis factor alpha . It is used to treat autoimmune diseases. Remicade is marketed by Janssen Biotech, Inc...
, etanercept
Etanercept
Etanercept is a drug that treats autoimmune diseases by interfering with the tumor necrosis factor by acting as a TNF inhibitor. Pfizer describes in a SEC filing that the drug is used to treat rheumatoid, juvenile rheumatoid and psoriatic arthritis, plaque psoriasis and ankylosing spondylitis...
, golimumab
Golimumab
Golimumab is a human monoclonal antibody which is used as an immunosuppressive drug and marketed under the brand name Simponi. Golimumab targets tumor necrosis factor alpha , a pro-inflammatory molecule and hence is a TNF inhibitor....
, certolizumab pegol
Certolizumab pegol
Certolizumab pegol is a therapeutic monoclonal antibody produced by UCB for the treatment of Crohn's disease and rheumatoid arthritis.-Method of action:...
and adalimumab
Adalimumab
Adalimumab is the third TNF inhibitor, after infliximab and etanercept, to be approved in the United States. Like infliximab and etanercept, adalimumab binds to TNFα, preventing it from activating TNF receptors; adalimumab was constructed from a fully human monoclonal antibody, while infliximab...
.
Biologics may increase the risk of both minor and serious infections. More rarely, they may be associated with nervous system disorders, blood disorders or certain types of cancer.
Other treatments
Doctors may use joint injectionJoint injection
In medicine, a joint injection is a procedure used in the treatment of inflammatory joint conditions, such as rheumatoid arthritis, psoriatic arthritis, gout, tendinitis, bursitis and occasionally osteoarthritis...
s with corticosteroid
Corticosteroid
Corticosteroids are a class of steroid hormones that are produced in the adrenal cortex. Corticosteroids are involved in a wide range of physiologic systems such as stress response, immune response and regulation of inflammation, carbohydrate metabolism, protein catabolism, blood electrolyte...
s in cases where one joint is severely impacted. In psoriatic arthritis patients with severe joint damage orthopedic surgery
Orthopedic surgery
Orthopedic surgery or orthopedics is the branch of surgery concerned with conditions involving the musculoskeletal system...
may be implemented to correct joint destruction, usually with use of a joint replacement
Joint replacement
Replacement arthroplasty [from Greek arthron, joint, limb, articulate, + -plassein, to form, mould, forge, feign, make an image of], or joint replacement surgery, is a procedure of orthopedic surgery in which the arthritic or dysfunctional joint surface is replaced with an orthopaedic prosthesis...
. Surgery is effective for pain alleviation, correcting joint disfigurement, and reinforcing joint usefulness and strength.
Self care
People with psoriatic arthritis and other forms of arthritis may find day to day tasks difficult. Adjustments include using gadgets such as jar openers to twist the lids from jars, lifting heavy pans or other objects with both hands, etc.Maintaining a healthy weight places less strain on the joints, leading to reduced pain and increased energy and mobility.
Regular exercise is recommended for people with arthritis to help maintain flexibility and strength. Biking, swimming and walking are commonly recommended.
Hot and cold packs can relieve inflamed joints. Cold has a numbing effect and can dull the sensation of pain. Heat can help relax tense muscles and relieve pain.
Epidemiology
Seventy percent of people who develop psoriatic arthritis first show signs of psoriasisPsoriasis
Psoriasis is an autoimmune disease that appears on the skin. It occurs when the immune system mistakes the skin cells as a pathogen, and sends out faulty signals that speed up the growth cycle of skin cells. Psoriasis is not contagious. However, psoriasis has been linked to an increased risk of...
on the skin, 15 percent develop skin psoriasis and arthritis at the same time, and 15 percent develop skin psoriasis following the onset of psoriatic arthritis.
Psoriatic arthritis can develop in people who have any level severity of psoriatic skin disease from mild to very severe.
Psoriatic arthritis tends to appear about 10 years after the first signs of psoriasis
Psoriasis
Psoriasis is an autoimmune disease that appears on the skin. It occurs when the immune system mistakes the skin cells as a pathogen, and sends out faulty signals that speed up the growth cycle of skin cells. Psoriasis is not contagious. However, psoriasis has been linked to an increased risk of...
. For the majority of people this is between the ages of 30 and 55, but the disease can also affect children. The onset of psoriatic arthritis symptoms before symptoms of skin psoriasis is more common in children than adults.
More than 80% of patients with psoriatic arthritis will have psoriatic nail lesions characterized by nail pitting, separation of the nail from the underlying nail bed, ridging and cracking, or more extremely, loss of the nail itself (onycholysis
Onycholysis
Onycholysis refers to the detachment of the nail from the nail bed, starting at its distal and/or lateral attachment. It is said to occur particularly on the ring finger but can occur on any of the fingernails. The most common cause of onycholysis is psoriasis. It can also occur in thyrotoxicosis...
).
Men and women are equally affected by this condition. Like psoriasis
Psoriasis
Psoriasis is an autoimmune disease that appears on the skin. It occurs when the immune system mistakes the skin cells as a pathogen, and sends out faulty signals that speed up the growth cycle of skin cells. Psoriasis is not contagious. However, psoriasis has been linked to an increased risk of...
, psoriatic arthritis is more common among Caucasians than African or Asian Americans.