Comprehensive evaluation of finger flexor tendon entheseal soft tissue and bone changes by ultrasound can differentiate psoriatic arthritis and rheumatoid arthritis.

OBJECTIVES: To determine whether a detailed sonographic evaluation of the hand flexor tendon compartment could help differentiate between psoriatic arthritis (PsA) and rheumatoid arthritis (RA). METHODS: Thirty-seven patients with PsA, 47 with RA and 10 healthy controls (HC) had flexor tendon (FT) compartment imaging of the dominant hand 2nd to 4th tendons using grey scale (GS) and power Doppler (PD) ultrasound (US) with evaluation for tenosynovitis, peri-tendinous lesions, soft tissue oedema and bony changes at FT insertions. 24/37 PsA and 19/47 RA cases had morning stiffness and 19/37 PsA and 10/47 RA had swollen and/or tender fingers. RESULTS: Tenosynovitis was more common in PsA (25/37) despite higher DAS28 scores in RA (25/37 versus 10/45; p<0.001). Peri-tendinous dermal soft tissue oedema with associated PD signal was evident in one third of PsA patients but in no RA patients (p=0.003). Flexor tendon enthesopathy including new bone formation at the insertional site was significantly more common in PsA (p=0.001). Considering a total inflammatory score per patient summing up the three modifications of the flexor tendon (tenosynovitis, peri-tendinous oedema and insertional enthesophytes) the difference between PsA and RA remained statistically significant (p<0.001). CONCLUSIONS: Our study adds to the growing body of literature that high resolution US of the hand FT compartment may help differentiate between RA and PsA, which needs assessment in the diagnostic setting.

A Beacon in the Dark: Canakinumab. A New Therapeutic Perspective in Chronic Tophaceous Gout.

Gout is the most common form of arthritis in adults. It is often associated with other comorbidities, which contraindicate the use of conventional therapies. The discovery of the role of interleukin-1ß (IL-1ß) in orchestrating the monosodium urate crystal-induced inflammatory response offered new therapeutic prospects to refractory patients, or to those in whom standard therapies are contraindicated. This paper describes a clinical case of a 65-year-old man with chronic tophaceous gouty arthropathy and subintrant flares, who had comorbidities contraindicating the use of conventional gout therapies-to which he did not respond-who was treated with canakinumab, a monoclonal selective inhibitor of IL-1ß. The patient reported a gradual, rapid, and significant reduction in pain, with a response observed within 12 h of the administration of the drug. Consistent with previous clinical studies, canakinumab appeared to be a viable, safe, and effective alternative to conventional therapies in this patient with gout who had limited therapeutic options. FUNDING: Novartis Farma, Italy.

'Deep Koebner' phenomenon of the flexor tendon-associated accessory pulleys as a novel factor in tenosynovitis and dactylitis in psoriatic arthritis.

OBJECTIVES: Skin and joint involvement in psoriasis (PsO) and psoriatic arthritis (PsA) are thought to relate to the so-called Koebner response. Given that dactylitis is non-randomly distributed in the digits, this study tested the hypothesis that the accessory pulleys linked to the flexor tendons were thickened in PsA and thus exhibited koebnerisation. METHODS: Ninety-six subjects (27 PsA, 27 rheumatoid arthritis (RA), 23 PsO and 19 healthy controls (HCs)) were enrolled. The A1, A2 and A4 pulley thickness was measured using a high-resolution probe (22 MHz). All patients were in remission or low disease activity with current dactylitis being excluded. RESULTS: Within 864 pulleys investigated, patients with PsA had thicker pulleys in every digit compared with both RA (P<0.001 and P=0.003) and HCs (P<0.001). RA and PsO groups had some pulleys in some digits thicker than HCs whereas some others were comparable. The second digit A1 pulley thickness was higher in patients with PsA with previous dactylitis (P=0.020). More pulleys were thickened in the PsA group (165/243, 68%) than RA (41/243, 17%; P<0.001) and HCs (13/171, 7.6%; P<0.001). CONCLUSIONS: In established PsA, the accessory pulleys are thickened compared with RA, PsO or HCs and especially in subjects with a history of dactylitis. These findings implicate the involvement of pulleys in PsA-related tenosynovitis and dactylitis supporting the idea of deep koebnerisation in dactylitis and sites of high physical stress.