Key Points

• Psoriatic arthritis affects 5% to 7% of psoriasis patients.

• Arthritis can occur before or after psoriatic lesions.

• Obtaining family history for psoriasis is important in those without current diagnosis and active psoriatic lesions.

Psoriatic arthritis is seen in approximately 5% to 7% of psoriasis patients, but it might affect up to 40% of hospitalized patients with extensive psoriatic lesions (Cuellar et al., 1994). The associated inflammatory peripheral arthritis might be monoarticular, asymmetric oligoarticular, or symmetric polyarticular, resembling RA. RF is usually absent. Psoriatic arthritis is associated with multiple HLA genes; environmental factors such as infections and physical trauma likely are also involved.

Psoriatic skin lesions predate arthritis in 70% of patients, occur with arthritis in 15%, and follow arthritis in 15%. Family history of psoriasis is therefore important for diagnosis in patients with an arthritis similar to psoriatic but without a known history. Psoriatic arthritis often manifests initially as an asymmetric monoarticular or oligoarticular arthritis of a large joint, such as a knee, evolving into asymmetric polyar-ticular arthritis. The distribution of involvement of psoriatic arthritis might resemble RA but involves the DIP joints more often, as well as causing enthesitis. Psoriatic arthritis might also cause spondylitis, sacroiliitis, chest wall pain from enthesitis, arthritis mutilans (destruction of phalanges and metacarpals, causing telescoping of fingers), conjunctivitis, and Achilles tendon and plantar fascia involvement. Radiographic abnormalities include marginal erosions at DIP and PIP joints, with new bone formation.

In addition to treating the psoriatic skin lesions, the arthritis is treated first with NSAIDs, followed by DMARDs for widespread disease and corticosteroid injections if only one or two joints are involved (Cuellar et al., 1994). A Cochrane analysis showed that high-dose methotrexate and sulfasalazine have efficacy in psoriatic arthritis (Jones et al., 2000). Aza-thioprine, etretinate, low-dose methotrexate, and colchicines all had some effectiveness versus placebo, but more studies are necessary. Anti-TNF medications are also used if patients continue to have symptoms despite DMARD treatment or if axial disease is present and NSAIDs have not worked. A meta-analysis of RCTs showed that anti-TNF drugs are effective against psoriatic arthritis (Saad et al., 2008). When contemplating local steroid joint injection the physician should keep in mind that bacterial colonization of psoriatic skin lesions with streptococcus or staphylococcus is common. Injecting through skin lesions should therefore be avoided.

How To Reduce Acne Scarring

How To Reduce Acne Scarring

Acne is a name that is famous in its own right, but for all of the wrong reasons. Most teenagers know, and dread, the very word, as it so prevalently wrecks havoc on their faces throughout their adolescent years.

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