Arthritis: The root word “arthro” means joint, and the suffix “itis” means inflammation. Combined it literally means joint inflammation but can also affect tissues around a joint. Therefore, the most common symptoms of arthritis are joint pain, stiffness, decreased range of motion, swelling, and sometimes deformation over time. There are different types of arthritis and in some diseases in which arthritis occurs, other organs such as your eyes, heart, skin, can also be affected. In a broad definition, there are more than 100 different types of arthritis. Common types of arthritis include:
- Osteoarthritis: This is typically the type of arthritis most people think about when they think of arthritis and is the most common form of arthritis. It is a breakdown of the articular cartilage that covers the articulating surfaces of the bones that for the joint and is usually the result of wear and tear on the joint cartilage over time.
- Ankylosing Spondylitis: This type affects the spinal column.
- Gout: this is where uric acid crystals to build up in joints and produce swollen and inflamed joints, often affecting the big toe, but may also affect other joints.
- Inflammatory Bowel Disease: This autoimmune disease is also associated with arthritis that affects the large intestine.
- Juvenile Arthritis: This as the name implies is an arthritis that attacks the joints of children.
- Lupus: Lupus is a chronic, autoimmune disease that can damage any part of the body, including joints.
- Lyme’s Disease: If Lyme disease bacteria enters the tissues of a joint it can cause joint inflammation.
- Psoriatic Arthritis: This type can occur in people who have psoriasis that produces scaly red and white patches of skin. It affects the skin, joints, and areas where tissues attach to the bone.
- Reactive Arthritis: This type produces pain and swelling in a joint that is caused by an infection in the body. It may also be accompanied by red, swollen eyes and a swollen urinary tract.
- Rheumatoid Arthritis: This is an autoimmune disease where the body’s immune defense system malfunctions and attacks joints and bones (usually hands and feet) and may also affect internal organs.
- Septic Arthritis: Septic arthritis is inflammation of the joints of the body secondary to an infectious etiology such as bacterial, fungal, mycobacterial, viral, or other pathogens.
- Sjogren Syndrome: Sjogren’s syndrome, an immune disorder that attacks the body’s own healthy cells and often occurs with other disorders, such as Rheumatoid arthritis and lupus.
One in four adults has arthritis, representing approximately 60 million people in the United States. It is the leading cause of work disability, with annual costs for medical care and lost earnings totaling $303.5 billion.
More than half of US adults (57.3%) with arthritis are of working age (18-64 years). One in ten adults has limited activity due to their arthritis.
Osteoarthritis (OA): Osteoarthritis is a degenerative disease that results in the breakdown of friction preventing cartilage that surrounds and cushions the articulating surfaces of the bones whose union makes a joint. It is typically thought of as a “wear and tear” disease that gradually leaves the exposed bony surfaces of a joint to compress and rub on each other causing chronic pain, joint stiffness, loss of mobility and flexibility, and inflammation of the soft tissues around the joint. The joints most commonly affected are the spine, hips, knees, and hands. Its primary risk factors include age, female gender, obesity, muscle weakness and imbalance, and joint trauma.
Osteoarthritis is classified into two categories: Primary osteoarthritis – diagnosed in the absence of the predisposing trauma or disease but is associated with the previously identified risk factors. Secondary osteoarthritis – occurs as a result of a preexisting joint abnormality. Predisposing conditions include trauma or injury, congenital joint disorders, inflammatory arthritis, avascular necrosis, infectious arthritis, Paget disease, osteopetrosis, osteochondritis dissecans, metabolic disorders (hemochromatosis, Wilson’s disease), hemoglobinopathy, Ehlers-Danlos syndrome, or Marfan syndrome.
- OA affects about 3.3% to 3.6% of the world’s population, causing moderate to severe disability in 43 million people, making it the 11th most debilitating disease worldwide.
- In the United States, it is estimated that 80% of the population over 65 years old has radiographic evidence of OA, although only 60% of this subset has symptoms, making it the most common form of arthritis.
- Spine: In patients over the age of sixty, 95% of men and 70% of women have at least one indicator of arthritis. Cervical spine osteoarthritis is present in over 80% of individuals over the age of 55. Specifically, facet joint arthritis is present in 19% of individuals between the ages of 45 and 65 years of age and 57% of patients over the age of 65 in the United States. Lumbar spine osteoarthritis affects approximately 30% of men and 28% of women from the ages of 55 to 64 in the United States. The L4-5 and L5-S1 vertebral levels are most commonly affected due to their higher load and joint mobility. A separate study found lumbar osteoarthritis-related back pain in over 20% of men and 22% of women between the ages of 45 and 64. Sixty-seven percent of patients between the ages of 45 to 64 and 89% of patients over 65 had evidence of facet joint arthropathy on imaging. There may also be ethnic differences in spine osteoarthritis, with a lower prevalence in Asians than whites. Often, osteoarthritic changes of the spine are more advanced in males than in females.
- Hip: Hip OA affects 7%–25% of people older than 55 years. Lifetime risk for symptomatic hip OA is 18.5% for men and 28.6% for women. Hip OA affects 7%–25% of people older than 55 years. Hip OA affects 7%–25% of people older than 55 years. Hip OA affects 7%–25% of people older than 55 years. Hip OA affects 7%–25% of people older than 55 years. The prevalence of primary radiographic hip OA increased from 0.7% in the 40–44 age group to 14% in the 85+ age group.
- Knee: Symptomatic knee OA occurs in 10% men and 13% in women aged 60 years or older. About 10% of people aged over 55 years have painful disabling knee OA of whom one quarter are severely disabled. Prevalence of knee OA in men is lower compared with women. This was shown in a meta-analysis of males and females in which the incidence of knee OA in males aged
- Hand: Estimates from the Zoetermeer survey found that radiographic involvement of the distal interphalangeal joint (DIP) affected more than half of men over the age of 65 and more than half of women over the age of 55. Thirteen percent of men and 26% of women over the age of 70 were found to have symptomatic hand OA involving at least one joint in the Framingham study. Yearly incidence rates from the Fallon Community Health Plan for hand OA were 0.35% and 0.21% for men and women over the age of 60 respectively. The incidence rates for those younger than 60 were dramatically lower.
Ankylosing Spondylitis (AS): Defined as a type of chronic, inflammatory arthritis that mainly affects the spine causing chronic back pain and progressive spinal stiffness as the most common features. Other characteristics and complications that may accompany the disease are buttock pain, hip pain, peripheral arthritis, enthesitis, inflammatory bowel disease, and vertebral fragility.
- The US population prevalence of AS is estimated to be 0.9%.
- AS is typically diagnosed in people (more common among men than women) younger than 40 years, with about 80% of patients developing symptoms when they are younger than 30 years.
Gout: Gout is one of the most common causes of chronic inflammatory arthritis in the United States, characterized by monosodium urate (MSU) monohydrate crystals deposition in the tissues. Hyperuricemia is the leading cause of gout. People with higher serum urate levels are not only at an elevated risk for gout flare-ups but will also have more frequent flare-ups over time. In a study of more than 2000 older adults with gout, those with levels more than 9 mg/dl were three times more likely to have a flare over the next 12 months than those with levels less than 6 mg/dl. Hyperuricemia is not the only risk factor for gout, and in fact, only a minority of these patients develop gout. Other factors implicated for gout and/or hyperuricemia include older age, male sex, obesity, a purine diet, alcohol, medications, comorbid diseases, and genetics.
- The prevalence of gout can vary by age, sex, and country of origin. In general, the prevalence of gout is 1 to 4%.
- In western nations, the prevalence of gout in men (3 to 6%) is 2 to 6 fold higher than in women (1 to 2%).
- Gout prevalence estimates in the United States range from less than three million to eight million or more individuals.
Inflammatory Bowel Syndrome (IBS): IBS is broadly defined as the presence of abdominal pain or discomfort with altered bowel habits. The pathophysiology of IBS includes abnormalities involving motility, visceral sensation, brain-gut interaction, and psychosocial distress. As such, altered gut immune activation, and intestinal and colonic microbiome are associated with IBS. Environmental contributors include early life stressors, food intolerance, antibiotics, and enteric infections. IBS can also be broken down into more specific diagnoses which includes IBS with diarrhea (IBS-D), IBS with constipation (IBS-C), and IBS with mixed bowel patterns (IBS-M). The prevalence of these three diagnoses differs in the United States versus Europe. In the United States, there is an equal distribution of these diagnoses whereas in Europe IBS-C or IBS-M can be more prevalent.
- Studies have demonstrated that the prevalence of IBS ranges between ten and fifteen percent, however, the majority of these patients do not seek medical care.
- In the United States, Canada, and Israel, IBS symptoms are 1.5 to 2 times more prevalent among women than men.
- IN individuals with IBS, women are more likely to report abdominal pain and constipation whereas men are more likely to report diarrhea.
- The prevalence of IBS also decreases with age.
Juvenile Idiopathic Arthritis (JIA): Juvenile idiopathic arthritis is the most common chronic rheumatological condition in children. There are seven different JIA subtypes with distinct phenotypes, genetic predispositions, pathophysiology, laboratory findings, disease course, and prognosis. They are a) oligoarthritis; b) rheumatoid factor (RF) positive polyarthritis; c) RF negative polyarthritis; d) systemic arthritis; e) psoriatic arthritis; f) enthesitis-related arthritis; g) undifferentiated arthritis.
- JIA is the most common rheumatic disease reported in children of the Western world. The incidence and prevalence are varied among 1.6 to 23 new cases for 100000 children, and 3.8 to 400 cases per 100000 children depend upon study designs, disease categories, and geographical areas.
- In a US and Canada study, the incidence of JIA is 0.041 to 0.061 per 1000 children.
- The Utah Population Database provides the prevalence of 1.2 per 1000 in white populations.
- The frequencies of different subtypes are 50% to 60% for oligoarthritis, 11% to 28% for RF negative polyarthritis, 2% to 7% for RF positive polyarthritis, 10% to 20% for systemic arthritis, 2% to 15% for psoriatic arthritis, 1% to 7% for enthesitis-related arthritis.
- Most JIA subtypes occur predominantly in females except enthesitis-related arthritis mainly affects males, and systemic JIA affects males and females equally.
Lupus or Systemic Lupus Erythematosus (SLE):Systemic lupus erythematosus (SLE) is a systemic autoimmune disease, with multisystemic involvement. The disease has several phenotypes, with varying clinical presentations in patients ranging from mild mucocutaneous manifestations to multiorgan and severe central nervous system involvement.
- Varying prevalence and incidence rates of SLE have been reported, with differences mostly attributes to the population differences. The Georgia and Michigan lupus registries reported prevalence of 72.1 to 74.4 per 100,000 persons and incidence rates of 5.6 per 100,000 person-years in primarily Caucasian and African-American populations.
- African-Americans have the highest rates, and rates are higher among Asian and Hispanic populations compared to Caucasians.
- SLE predominantly affects women of childbearing age, with female to male ratio of 9 to 1. The risk, however, decreases after menopause in women although still is twice as compared to men.
- SLE is more severe in children while in the elderly, it tends to be more insidious onset and has more pulmonary involvement and serositis and less Raynaud's, malar rash, nephritis, and neuropsychiatric complications.
Psoriatic Arthritis: Psoriatic arthritis is an autoimmune disease that causes pain and swelling in joints as well as soft tissues such as ligaments and tendons that attach to bones. The arthritis condition is sometimes preceded with the person already having a skin condition called psoriasis (approx. 205 to 30%) that produces a painful red rash condition on the skin. It shares various clinical features with other rheumatoid arthritis conditions.
- Approximately 33 to 50% of psoriatic arthritis patients have at least one first degree relative who also has psoriasis or psoriatic arthritis.
- Psoriatic arthritis has been estimated to have a prevalence of 0.05% to 0.25% in the general population and around 6% to 41% in psoriasis patients. This variability of psoriatic arthritis in psoriasis is partially due to underdiagnosis. A meta-analysis showed the prevalence of undiagnosed psoriatic arthritis might be as high as 15.5%.
- The onset of psoriatic arthritis is usually in the 30s and 40s and occurs about equally in males and females.
- In the majority of patients, the onset of skin disease precedes that of arthritis (68%), in about 15% of patients, the arthritic manifestations coincide with the skin disease, and in 17% of patients, arthritis occurs before the skin manifestations making the diagnosis more difficult.
- When examining the occurrence of psoriatic arthritis over time in a population of patients with psoriasis, the annual incidence of psoriatic arthritis was 1.9 to 2.7% per 100 patients with psoriatic arthritis. The cumulative incidence of psoriatic arthritis in patients with psoriasis was 1.7% at 5 years, 3.1% at 10 years, 5.1% at 20 years, and 20.5% at 30 years.
Reactive Arthritis: Reactive arthritis occurs in response or in “reaction” to an infection triggered by a bacterial pathogen in the digestive, urinary, or reproductive systems which causes inflammation of the joints, or eyes, or urinary tract, or in all three. The manifestation of the condition usually manifests itself within several days or week after infection. The areas that seem to be most commonly affected by reactive arthritis are the knees, ankles, and the sacroiliac joint of the low back area. Reactive arthritis is most commonly found in people ages 20 to 40.Reactive Arthritis can be self-limiting, recurrent, or continuous, and about 20% to 25% of the patients may progress to have chronic articular, ocular, and cardiac complications.
- The incidence is about 2% to 4% after a urogenital infection, mainly with Chlamydia trachomatis, and varies from 0% to 15% after gastrointestinal infections with Salmonella, Shigella, Campylobacter, or Yersinia.
- Reactive arthritis is relatively rare, and the incidence in population-based studies is reported to be 0.6 to 27 per 100,000. Reactive arthritis is more common in adult males in the second and third decades of their life.
- About 1-3% of patients with nonspecific urethritis will develop an episode of arthritis. Overall, higher disease activity and worse functional capacity are seen in the lower socioeconomic populations.
Rheumatoid Arthritis (RA): RA is a systemic autoimmune and inflammatory disease where the body’s immune defense system malfunctions and attacks cells and tissues (usually joint soft tissues and bones) in the body. It is thought to result from the interaction between patients’ genotype and environment. The most commonly affected joints are the hands, wrists, and knees and may also affect internal organs. Joint inflammation and damage to joint cartilage and bone can overtime cause chronic pain, joint instability, swelling, and deformity.
- The heritability of rheumatoid arthritis is approximately 40% to 65% for seropositive rheumatoid arthritis and 20% for seronegative rheumatoid arthritis.
- The worldwide prevalence of RA is about 0.24%. The annual incidence of RA in the United States and other western nations of northern Europe is about 40 per 100,000 persons.
- According to epidemiologic data, RA is more prevalent in women compared to men, with a lifetime risk of RA 3.6% in women compared to 1.7% in men.
- RA risk also increases with age, with a peak incidence between age 65 to 80 years of age.
- The typical 'western' diet that is rich, high in caloric content, and low in fiber increases the risk of RA.
- Among modifiable risk factors, cigarette smoking has the strongest association with RA. Diet and nutrition have been shown to play a significant role as environmental triggers for RA.
- Obesity is another well-established risk factor for RA. There is a 30% increase in the risk of RA for patients with a body mass index (BMI) of greater than 30 kg/m^2 and a 15% increased risk for those with a BMI of 25 to 29.9 kg/m^2.
Septic Arthritis: Septic arthritis is inflammation of the joints of the body secondary to an infectious etiology such as bacterial, fungal, mycobacterial, viral, or other pathogens. Septic arthritis is usually monoarticular involving one large joint such as the hip or knee; however, polyarticular septic arthritis involving multiple or smaller joints may also occur. A study of the healthcare burden of septic arthritis in the United States between 2009 and 2012 showed a 26% increase in total charges and a 24% increase in inpatient charges for septic arthritis but no time trends in duration or outcomes of admissions.
- The incidence of septic arthritis is between 2 to 6 cases per 100,000 people but varies based on the presence of risk factors.
- Septic arthritis is more common in children than in adults. The incidence of septic arthritis peaks between ages 2 and 3 years and has a male predominance (2:1). Subgroups of children at high risk include neonates, hemophiliacs with hemarthroses, immunocompromised (e.g., sickle cell anemia, human immunodeficiency virus infection), and those treated with chemotherapy.
- Risk factors in adults include age older than 80, diabetes mellitus, rheumatoid arthritis, recent joint surgery, joint prosthesis, previous intra-articular injection, skin infections and cutaneous ulcers, Human immunodeficiency virus, osteoarthritis, sexual activity (especially in cases of suspected gonococcal septic arthritis), other causes of sepsis.
Sjogren Syndrome: Primary Sjogren syndrome is a systemic autoimmune disorder commonly presenting with dryness involving the eyes and mouth due to inflammation and resultant pathology of the lacrimal and salivary glands. Up to one-half of affected individuals also develop extra-glandular involvement in organs such as the joints, skin, lungs, gastrointestinal (GI) tract, nervous system, and kidneys. This condition is frequently associated with other autoimmune disorders including rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE).
- Sjogren syndrome has an incidence approaching approximately one-half of that of rheumatoid arthritis (RA) or affecting 0.5% to 1.0% of the population.
- Between 400,000 and 3.1 million adults have Sjögren's syndrome. This condition can affect people of any age, but symptoms usually appear between the ages of 45 and 55. About half of patients also have rheumatoid arthritis or other connective tissue diseases, such as lupus.
- Sjogren has been reported worldwide in adults and more rarely in children, and there appears to be no racial, or geographic bias in incidence. The disorder, however, has a marked predilection for women and similar to SLE, the female:male ratio is approximately 9:1. The disease usually presents in middle age but may occur in children as well as the elderly.