Most Read Articles
Jairia Dela Cruz, 3 days ago
The selective serotonin reuptake inhibitor escitalopram holds promise in the prevention of Alzheimer’s disease, reducing amyloid-β-42 levels in cerebrospinal fluid and brain tissue in older adults with normal cognitive function, according to recent evidence.
Pearl Toh, 26 Nov 2020
Inhaled corticosteroid (ICS) should be the mainstay of long-term asthma management — such is the key message of the latest Singapore ACE* Clinical Guidance (ACG) for asthma, released in October 2020.
Elvira Manzano, 17 Nov 2020
Invasive fungal infections, particularly those caused by Candida species, are common in hospitalized, immunocompromised, or critically ill patients and are associated with considerable morbidity and mortality.
4 days ago
A meta-analysis suggests that virtual reality therapy helps older adults improve their functional mobility as compared with conventional interventions, although the quality of evidence is low.

Role of dermatologists in treating psoriatic arthritis

Prof. Alice Gottlieb
Icahn School of Medicine at Mount Sinai
New York, US
10 Nov 2020
Psoriatic arthritis (PsA) affects about one-third of patients with psoriasis. At a recent symposium in Hong Kong, Professor Alice Gottlieb of the Icahn School of Medicine at Mount Sinai, New York, US,  provided practical guidance for dermatologists for detecting PsA in patients with psoriasis and outlined the clinical presentation, risk factors, and treatment options for this inflammatory disease.

PsA is a potentially progressive, debilitating, systemic inflammatory disease that occurs in approximately 30 percent of patients with psoriasis. Patients develop PsA independently of the severity of their psoriasis, with >50 percent of PsA patients having mild or moderate psoriasis. [JAMA Dermatol 2013;149:1180-1185] PsA manifests in six domains: peripheral arthritis, axial disease, enthesitis, dactylitis, skin and nails. [J Dermatolog Treat 2020;31:662-679]

Importance of early diagnosis

“Dermatologists play a critical role in the early detection of PsA since cutaneous disease precedes PsA by an average of 10–12 years in most patients,” said Gottlieb.  [J Dermatolog Treat 2006;17:343-352; J Am Acad Dermatol 2005;52:1-19]However, PsA remains undiagnosed in many patients with psoriasis. A delay in PsA diagnosis of ≥6 months increases the risk of peripheral joint erosions and poor functional outcomes.” [J Am Acad Dermatol 2014;71:649-655; Ann Rheum Dis 2015;74:1045-1050]

In addition, PsA is associated with a higher level of comorbidities (including cardiovascular disease, hyperlipidaemia, obesity, diabetes, cancer, uveitis, and depression/anxiety) than psoriasis. [Arthritis Care Res (Hoboken) 2011;63:1729-1735]

Dermatologists treating patients with psoriasis need to screen for PsA, so that early PsA treatment can be initiated to prevent disability,” Gottlieb emphasized.

Indicators of PsA risk

The risk of PsA is increased in patients with psoriatic scalp lesions, inverse psoriasis, and nail psoriasis. A first-degree relative with psoriasis, severe psoriasis, obesity, subclinical muscular-skeletal inflammation, and the presence of certain biomarkers are also important risk factors. [Nat Rev Rheumatol 2019;15:153-166]

Enthesitis [inflammation where the tendon or ligament inserts into bone] is present in 35 percent of patients with early PsA,” said Gottlieb. [Arthritis Care Res (Hoboken) 2017;69:1685-1691] “Patients are often unaware of pain in these regions until the entheses are squeezed. In particular, the Achilles tendon insertion, plantar fascia or the lateral epicondyles should be examined.”

Diagnosis of PsA

Diagnosis of PsA according to CASPAR (Classification Criteria for Psoriatic Arthritis) criteria requires the presence of inflammation of the joint, enthesitis or spine. In addition, patients must score 3 points   from the following features: current psoriasis (2 points) or personal history of psoriasis or family history of psoriasis (1 point) dactylitis, juxta-articular new bone formation, rheumatoid factor negativity, or nail dystrophy (1 point each). [Arthritis Rheum 2006;54:2665-2673]

“Diagnosis of PsA can be complicated by the overlapping symptoms of many musculoskeletal diagnoses,” said Gottlieb. (Table) [J Am Acad Dermatol 2014;71:649-655; J Am Acad Dermatol 2008;58:851-864; Drugs 2014;74:423-441]

HK-SDV-098_01

Screening for PsA

Screening for PsA is done with the Psoriasis Epidemiology Screening Tool (PEST) and using a simple mnemonic “PsA”, which can be completed by patients at or before their visit to the clinic. [J Rheumatol 2011;38:551-552; J Am Acad Dermatol 2015;7:905-906]

The PEST questionnaire consists of five yes/no questions and a labelled diagram to indicate where the patient feels tender or sore. Patients who check “yes” to 3 questions should be considered at high risk of having PsA. [J Rheumatol 2011;38:551-552]

The “PsA” mnemonic is based on the presence of P (pain in joints), S (stiffness, swelling and/or sausage digits), and A (axial/spine involvement), with the presence of ≥2 of these factors indicating a risk of PsA. [J Am Acad Dermatol 2015;72:905-906]

Treatment options

NSAIDs are used to control pain and inflammation in peripheral arthritis and axial disease, but do not alter the natural history of PsA. Intra-articular corticosteroids are useful for peripheral disease, but also do not alter disease progression. Topical agents and phototherapy are effective for skin disease only. Disease-modifying antirheumatic drugs (DMARDs) control symptoms of peripheral arthritis, as well as skin and nail disease, but are generally not as effective as biologics.  Methotrexate is ineffective for axial disease. [J Dermatolog Treat 2020;31:662-679; J Rheumatol 2006;33:1417-1421; Ann Rheum Dis 2020;79:700-712]

Tumour necrosis factor (TNF) inhibitors are used across all PsA domains and inhibit radiographic progression. “However, their efficacy in axial PsA is inferred from data from ankylosing spondylitis trials,” Gottlieb noted. [J Dermatolog Treat 2020;31:662-679; J Rheumatol 2006;33:1417-1421; Ann Rheum Dis 2020;79:700-712]

Ustekinumab, a monoclonal antibody targeting interleukin-12 (IL-12) and IL-23, has received US FDA approval for treating signs and symptoms of peripheral arthritis, but not for inhibiting radiographic progression. It is effective for skin and nail disease, dactylitis and enthesitis, but does not have US FDA approval for axial disease. [J Dermatolog Treat 2020;31:662-679; J Am Acad Dermatol 2008;58:851-864; Stelara US prescribing information 2016; Ther Adv Chronic Dis 2018;9:191-198] The IL-23/p19 inhibitor guselkumab has received US FDA approval for treatment across all domains, except axial PsA. [J Dermatolog Treat 2020;31:662-679; Tremfya US prescribing information 2017]

IL-17 inhibitors, such as secukinumab and ixekizumab, are effective across all domains of PsA, including inhibition of radiographic progression. [J Dermatolog Treat 2020;31:662-679; Cosentyx US prescribing information 2018; TALTZ US prescribing information 2019] Secukinumab has demonstrated efficacy and safety in the MAXIMISE trial, the first randomized, double-blind, placebo-controlled study to investigate a biologic in patients with axial PsA. [Ann Rheum Dis 2019;78:195-196] Head-to-head studies comparing IL-17 inhibitors (secukinumab or ixekizumab) with the TNF inhibitor adalimumab showed that both IL-17 inhibitors and TNF inhibitors are effective in treating disease in the joints. However, IL-17 inhibitors achieved clearer skin, an aspect of treatment important for patients with PsA. [Lancet 2020;395:1496-1505; Ann Rheum Dis 2020;79:123-131; Ann Rheum Dis 2019;78:1215-1219]

The JAK inhibitor tofacitinib is approved by US FDA for treating the signs and symptoms of PsA, dactylitis and enthesitis only. [J Dermatolog Treat 2020;31:662-679; Xeljanz US prescribing information 2018]

Conclusion

Dermatologists play a key role in PsA management. Early diagnosis of PsA in patients with psoriasis by dermatologists can ensure initiation of appropriate treatment, which helps prevent PsA progression, irreversible joint damage, and resultant permanent disability.

Editor's Recommendations
Most Read Articles
Jairia Dela Cruz, 3 days ago
The selective serotonin reuptake inhibitor escitalopram holds promise in the prevention of Alzheimer’s disease, reducing amyloid-β-42 levels in cerebrospinal fluid and brain tissue in older adults with normal cognitive function, according to recent evidence.
Pearl Toh, 26 Nov 2020
Inhaled corticosteroid (ICS) should be the mainstay of long-term asthma management — such is the key message of the latest Singapore ACE* Clinical Guidance (ACG) for asthma, released in October 2020.
Elvira Manzano, 17 Nov 2020
Invasive fungal infections, particularly those caused by Candida species, are common in hospitalized, immunocompromised, or critically ill patients and are associated with considerable morbidity and mortality.
4 days ago
A meta-analysis suggests that virtual reality therapy helps older adults improve their functional mobility as compared with conventional interventions, although the quality of evidence is low.