Sedentary Work Exerting up to 10 pounds (4.5 kg) of force occasionally and/or a negligible amount of force frequently or constantly to lift, carry, push, pull, or otherwise move objects, including the human body. Sedentary work involves sitting most of the time, but may involve walking or standing for brief periods of time. Jobs are sedentary if walking and standing are required only occasionally and other sedentary criteria are met.

Light Work Exerting up to 20 pounds (9.1 kg) of force occasionally and/or up to 10 pounds (4.5 kg) of force frequently, and/or negligible amount of force constantly to move objects. Physical demand requirements are in excess of those for Sedentary Work. Light Work usually requires walking or standing to a significant degree. However, if the use of the arm and/or leg controls requires exertion of forces greater than that for Sedentary Work and the worker sits most the time, the job is rated Light Work.

Medium Work Exerting up to 50 (22.7 kg) pounds of force occasionally, and/or up to 25 pounds (11.3 kg) of force frequently, and/or up to 10 pounds (4.5 kg) of forces constantly to move objects.

Heavy Work Exerting up to 100 pounds (45.4 kg) of force occasionally, and/or up to 50 pounds (22.7 kg) of force frequently, and/or in excess of 20 pounds (9.1 kg) of force constantly to move objects.

Very Heavy Work Exerting in excess of 100 pounds (45.4 kg) of force occasionally, and/or in excess of 50 pounds (22.7 kg) of force frequently, and/or in excess of 20 pounds (9.1 kg) of force constantly to move objects.

Job Classification

In most duration tables, five job classifications are displayed. These job classifications are based on the amount of physical effort required to perform the work. The classifications correspond to the Strength Factor classifications described in the United States Department of Labor's Dictionary of Occupational Titles. The following definitions are quoted directly from that publication.

Sedentary Work Exerting up to 10 pounds (4.5 kg) of force occasionally and/or a negligible amount of force frequently or constantly to lift, carry, push, pull, or otherwise move objects, including the human body. Sedentary work involves sitting most of the time, but may involve walking or standing for brief periods of time. Jobs are sedentary if walking and standing are required only occasionally and other sedentary criteria are met.

Light Work Exerting up to 20 pounds (9.1 kg) of force occasionally and/or up to 10 pounds (4.5 kg) of force frequently, and/or negligible amount of force constantly to move objects. Physical demand requirements are in excess of those for Sedentary Work. Light Work usually requires walking or standing to a significant degree. However, if the use of the arm and/or leg controls requires exertion of forces greater than that for Sedentary Work and the worker sits most the time, the job is rated Light Work.

Medium Work Exerting up to 50 (22.7 kg) pounds of force occasionally, and/or up to 25 pounds (11.3 kg) of force frequently, and/or up to 10 pounds (4.5 kg) of forces constantly to move objects.

Heavy Work Exerting up to 100 pounds (45.4 kg) of force occasionally, and/or up to 50 pounds (22.7 kg) of force frequently, and/or in excess of 20 pounds (9.1 kg) of force constantly to move objects.

Very Heavy Work Exerting in excess of 100 pounds (45.4 kg) of force occasionally, and/or in excess of 50 pounds (22.7 kg) of force frequently, and/or in excess of 20 pounds (9.1 kg) of force constantly to move objects.

Psoriatic Arthritis


Related Terms

  • Arthritis
  • Psoriasis
  • Psoriatic Arthropathy
  • Rheumatoid Psoriatic Arthritis
  • Spondylitic Psoriatic Arthritis

Differential Diagnosis

Specialists

  • Clinical Psychologist
  • Dermatologist
  • Family Physician
  • Infectious Disease Internist
  • Internal Medicine Physician
  • Occupational Therapist
  • Ophthalmologist
  • Orthopedic (Orthopaedic) Surgeon
  • Physiatrist (Physical Medicine and Rehabilitation Specialist)
  • Physical Therapist
  • Psychiatrist
  • Rheumatologist

Comorbid Conditions

Factors Influencing Duration

The severity and extent of the condition, effectiveness of treatment in reducing symptoms, attitude, and motivation of individual, and job demands will influence the length of disability.

Medical Codes

ICD-9-CM:
696.0 - Psoriatic Arthropathy

Overview

Psoriatic arthritis is an immune-mediated (autoimmune), connective tissue disease that is associated with a skin disorder marked by bumps and scaling (psoriasis) and is characterized by inflammation of the ligaments, tendons, fascia, and joint capsules (enthesitis) of the upper extremities, especially the hands. Small joints of the feet and large joints of the legs such as hips, knees, and ankles may be also involved. Most commonly, psoriatic arthritis affects fewer than five joints. Its arthroscopic symptoms and clinical findings are similar to those of rheumatoid arthritis, but it differs in its high frequency of distal joint involvement (joints farthest from the center of the body, such as small joints of hands and feet) and the serum of affected individuals is negative for rheumatoid factor.

Psoriatic arthritis occurs in five general patterns: arthritis affecting the small distal joints of toes and fingers (distal interphalangeal arthropathy), asymmetrical oligoarticular arthritis of the extremities, symmetrical polyarthritis that resembles rheumatoid arthritis, deforming and destructive arthritis (arthritis mutilans) with resorption of bone (osteolysis) and dissolution of the joint, and arthritis of the spine and sacroiliac joints (psoriatic spondylitis). These patterns may change in an individual over time.

The etiology of psoriatic arthritis is unknown, but genetic, immunologic and less conclusively, environmental factors such as infection and trauma are considered important components. The disease is associated with increased frequency of certain human leukocyte antigens (including HLA-B27, HLA-DR4m -DR7, and –Cw6) in the tissue of those affected with psoriasis and/or psoriatic arthritis. Genome scans have shown linkages to specific gene loci. Serum levels of immunoglobulins (IgA and IgG) are higher in psoriatic arthritis patients. Psoriasis is present years before the onset of arthritis in about 70% of individuals with psoriatic arthritis; 10% to 15% develop psoriasis and arthritis simultaneously, and 15% to 20% have arthritis before skin involvement (Ruderman).

Incidence and Prevalence: Incidence of psoriatic arthritis in the general population is estimated to be 1%; about 1 million adults in the US are affected (Hammadi) compared to 2 million with rheumatoid arthritis (Hammadi). Although incidence varies among countries, the incidence of psoriatic arthritis internationally ranges from 1% to 40% depending on the clinical criteria applied and whether all races are included (Van Voorhees). Prevalence is higher among whites than among African Americans and Native Americans; the disease occurs in 2.5% of white North Americans and 0.05% to 0.24% in the international white population (Hammadi).

Source: Medical Disability Advisor



Causation and Known Risk Factors

Individuals with psoriasis are at greatest risk for developing psoriatic arthritis; approximately 5% to 8% of individuals with psoriasis develop psoriatic arthritis (Hammadi). In contrast to rheumatoid arthritis, which affects women more than men, psoriatic arthritis shows no gender preference. Psoriatic arthritis usually occurs in individuals between ages 35 and 55 years, but can develop at any age. Risk is greater among whites than other races. A family history of psoriatic arthritis is a risk factor for developing the disease.

Source: Medical Disability Advisor



Diagnosis

History: The individual may describe a family history of psoriasis or psoriatic arthritis. The individual may complain of pain, stiffness, and swelling of the joints, especially the small joints of the hands and feet. Depending on the area affected by psoriatic arthritis, other complaints may include back pain, chest pain, pain on walking or climbing stairs, pain around the eyes, and shortness of breath. Humidity and temperature changes may affect arthritis symptoms. Fever may be present in patients with the arthritis mutilans subtype of psoriatic arthritis. Individual may report that psoriasis has been present for some time before arthritis symptoms or that psoriasis developed at the same time as arthritis symptoms. The physician will obtain a history of recent and prior illness, particularly bacterial or viral infections.

Physical exam: Psoriasis is usually present but may be limited to patches (lesions) between the buttocks, behind the ears, or other inconspicuous areas such as the umbilicus or scalp; psoriasis can be severe in some individuals. Swelling may be seen as well as deformity of the joints, especially finger joints in severe, chronic cases. Overgrowth of bone (hyperostosis) may be seen. "Sausage digits" (dactylitis) of the hands and feet are common in individuals with psoriatic arthritis. Affected joints often have a purplish discoloration. An accumulation of fluid may be seen in a joint (effusion). Nails of the affected digits may be pitted or crumbling (onycholysis). Inflammation of the outer membrane of the eyes (conjunctivitis) or the uveal tract (uveitis) may occur in up to 30% of individuals with psoriatic arthritis (Van Voorhees).

Tests: There is no specific diagnostic test for psoriatic arthritis; observing the pattern of joint involvement is essential to correct diagnosis. Blood tests that may be helpful in making the diagnosis include erythrocyte sedimentation rate and C-reactive protein to evaluate inflammation, hemoglobin, rheumatoid factor (to rule out rheumatoid arthritis), uric acid (to rule out gout), human leukocyte antigen (HLA) typing, and antinuclear antibodies. A sample of joint fluid may be analyzed to determine the number and type of white blood cells. A cytokine profile may be done to assess T cell and monocyte activation, which may help differentiate between psoriatic arthritis and rheumatoid arthritis. X-rays usually are done to help differentiate psoriatic arthritis from other types of arthritis based on degree of joint erosion. Depending on areas affected and symptoms reported by the individual, either CT or MRI imaging can be done to examine soft tissue and joint characteristics in more detail. CT scans of the sacroiliac joint are considered to be sensitive for viewing spondylitis or sacroiliitis. MRI is especially sensitive for assessing pathology of the hands and feet.

Source: Medical Disability Advisor



Treatment

Treatment of the polyarthritis component focuses on controlling inflammation. It is subdivided into nonpharmacological, pharmacological, and surgical therapies. Nonpharmacological therapies include rest, wearing of splints over the affected joints, joint protection, and physical therapy. Pharmacological measures include nonsteroidal/anti-inflammatory drugs (NSAIDs), occasional corticosteroid injections into the joints, disease modifying antirheumatic drugs (DMARDs), and newer, injectable biologic agents that target tissue necrosis factor (TNF) and other cytokines. Surgery (hip or knee replacement) may be indicated in severe cases.

The psoriasis component is treated with topical therapy, systemic medications, and photochemotherapy (psoralen plus UV light). Treatment is individualized and depends on the size and location of psoriasis plaques. Immunosuppressive drugs (e.g., methotrexate) and retinoic-acid derivatives may be given in cases of severe skin involvement. These drugs have demonstrated effectiveness for both skin and joint symptoms. Cyclosporine, an antibiotic, has also demonstrated good results for psoriasis and psoriatic arthritis although it has toxic effects in some individuals.

Exercise is an important component of a treatment plan for psoriatic arthritis, resulting in reduced pain, swelling, and stiffness. Sufficient rest is also required.

Source: Medical Disability Advisor



Prognosis

Many individuals with psoriatic arthritis have mild disease with episodic flares and remissions. Because psoriatic arthritis is a chronic disease, joint deformities and movement limitations may increase over time. However, most individuals can maintain reasonable function of the affected joints. Medication can lead to periods of symptom remission. Individuals with many affected joints (polyarthritis), a family history of arthritis, early onset (younger than 20 years of age), or severe skin psoriasis have a poorer prognosis. Inflammatory arthritis of the spine (spondylitis) may develop in some individuals. Some will progress to a severe stage characterized by joint disintegration (lysis) or immobility (ankylosis).

Source: Medical Disability Advisor



Rehabilitation

The goals of rehabilitation are to promote independence in all functional activities while protecting the involved joints. Because psoriatic arthritis is a progressive, systemic disease, individuals may benefit from a comprehensive rehabilitation program.

In conjunction with pharmacological management, rehabilitation focuses on stretching and strengthening the involved body parts. During an inflammatory period, care must be taken to protect the joints while preventing loss of motion and strength. Modalities such as heat and cold may be used (Braddom), and hydrotherapy is highly recommended, when available.

Rehabilitation should include general conditioning exercises that emphasize full range of motion and weight bearing exercises. This is especially important because loss of motion and osteoporosis are common in these individuals. Loss of motion results from changes within the joint, while osteoporosis may occur from prolonged use of steroids (Gladman, "Current Concepts").

Because this is a chronic condition, individuals should learn pain-control techniques (such as the use of heat, cold or relaxation) that they can perform at home. A lifetime program of walking, aquatic exercise, stretching exercises, and other physical fitness programs should be initiated prior to discharge from therapy. The therapist must instruct individuals in the importance of maintaining their level of fitness and independence while preventing joint damage.

Occupational therapy may also be necessary to address daily living activities. A home assessment might be indicated to ascertain that the environment is optimal for the individual's needs and to recommend assistive devices that might be helpful for common daily tasks.

An ergonomic evaluation may be beneficial to modify the work station so that individuals with psoriatic arthritis are able to maintain their employment status.

Because individuals may experience depression if their activities become restricted as the disease progresses, counseling or a support group might be needed.

Additional information may provide greater insight into the rehabilitation needs of this population (Gladman, "Assessment of Patients"; Veale).

FREQUENCY OF REHABILITATION VISITS
Nonsurgical
SpecialistPsoriatic Arthritis
Physical or Occupational TherapistUp to 24 visits within 12 weeks
The table above represents a range of the usual acceptable number of visits for uncomplicated cases. It provides a framework based on the duration of tissue healing time and standard clinical practice.

Source: Medical Disability Advisor



Complications

Development of severe destructive polyarthritis may complicate psoriatic arthritis and result in significant joint dysfunction and immobility. Development of inflammation of the spine (spondylitis) can result in neurologic complications. Some individuals may develop inflammation of the aortic valve, leading to aortic insufficiency. Secondary amyloidosis may develop occasionally.

Source: Medical Disability Advisor



Ability to Work (Return to Work Considerations)

Individuals are advised to avoid tasks that are potentially injurious including those that cause extreme joint stress and repetitive micro-injury. Work place modifications depend upon the location of the affected joints. Special attention must be paid to support for weak or injured muscles (orthotics) to improve weight-bearing patterns. The individual may need regular time off to participate in ongoing physical therapy. Company policy on medication usage should be reviewed to determine if pain medication use is compatible with job safety and function.

Source: Medical Disability Advisor



Failure to Recover

If an individual fails to recover within the expected maximum duration period, the reader may wish to consider the following questions to better understand the specifics of an individual's medical case.

Regarding diagnosis:

  • Does individual have any risk factors for psoriatic arthritis?
  • What other symptoms are present?
  • Does individual have psoriasis?
  • Were swelling, deformity of the joints, or other symptoms characteristic of psoriatic arthritis present on physical exam?
  • Has individual received appropriate diagnostic testing? Did result conform psoriatic arthritis?
  • Have conditions with similar symptoms been ruled out?

Regarding treatment:

  • Does individual take NSAIDs to control inflammation?
  • Did individual use nonpharmacological therapy, e.g., exercise, rest, joint protection?
  • Has individual responded favorably to medications?
  • Has surgery become necessary?

Regarding prognosis:

  • Has individual been instructed in physical therapy? Has individual incorporated the instructions into a home exercise program?
  • Is individual's employer able to accommodate work restrictions?
  • Does individual follow restrictions at home as well as at work?
  • Does individual have any underlying conditions such as AIDS that may affect recovery?
  • If needed, is individual in counseling with an appropriate mental health provider?
  • Does individual have any complications?

Source: Medical Disability Advisor



References

Cited

Braddom, Randolph L. Physical Medicine and Rehabilitation. 3rd ed. Philadelphia: W.B. Saunders, 2006.

Gladman, D. D. "Current Concepts in Psoriatic Arthritis." Current Opinion in Rheumatology 14 4 (2002): 361-366. National Center for Biotechnology Information. National Library of Medicine. 24 Oct. 2008 <PMID: 12118168>.

Gladman, D. D., et al. "Assessment of Patients with Psoriatic Arthritis: A Review of Currently Available Measures." Arthritis and Rheumatism 50 1 (2004): 24-35. National Center for Biotechnology Information. National Library of Medicine. 24 Oct. 2008 <PMID: 14730596>.

Hammadi, Anwar. "Psoriatic Arthritis." eMedicine. Eds. Kristine M. Lohr, et al. 14 May. 2008. Medscape. 6 Mar. 2009 <http://emedicine.medscape.com/article/331037-overview>.

Ruderman, Eric M. "Evaluation and Management of Psoriatic Arthritis: The Role of Biologic Therapy." Journal of American Academic Dermatology 49 2-Suppl (2003): S125-S132.

Van Voorhees, Abby, and Darice Williams Fadeyi. "Psoriatic Arthritis." eMedicine. Eds. Alexa Boer Kimball, et al. 26 Jan. 2007. Medscape. 6 Mar. 2009 <http://emedicine.com/derm/topic918.htm>.

Veale, D., and O. FitzGerald. "Psoriatic Arthritis." Best Practice & Research Clinical Rheumatology 16 4 (2002): 523-535. National Center for Biotechnology Information. National Library of Medicine. 24 Oct. 2008 <PMID: 12406425>.

General

Mercier, L. R. "Arthritis, Psoriatic." Ferri's Clinical Advisor: Instant Diagnosis and Treatment. Ed. Fred Ferri. 2004 ed. St. Louis: Mosby, Inc., 2004. 97-97.

Source: Medical Disability Advisor






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