Background/Purpose: Chikungunya (CHIK) is a
viral disease transmitted by the Aedes mosquito. The acute phase of the disease combines: fever, fatigue,
arthralgia, arthritis, rash . Studies of humans and animal models have shown that
disease signs and symptoms following infection  are associated with viral  infection of cells in musculoskeletal tissues,
such as fibroblasts and osteoblasts, and infiltration of inflammatory cells.

Joint imaging studies in CHIK are rare, except
one from Manimunda (3), showing joint effusion, bone
edema, synovial thickening, tenosynovitis and erosions on MRI in patients with
persistent pain beyond one month after the acute episode.

There are no data with ultrasound imaging.

Ultrasound showed interest in early diagnosis of
rheumatoid arthritis (RA), by analogy between these two diseases (RA / Chik) we hypothesized that ultrasound could be relevant to
study articular and juxta articular damage in early CHIK.

The EchoCHIK study is a prospective study part of the context of
studies of CHIK – during the epidemy that began in
Martinique in January 2014- aiming at describing ultrasound aspects of CHIK.
Preliminary results allow a description of joint
involvement during the acute phase.

Methods: patients with arthralgias and / or
arthritis related to CHIK for less than 10 days were included. Confirmation of
the diagnosis was made by serology or PCR. Exclusion criteria were:  history of chronic inflammatory rheumatic
disease, concomitant use of NSAIDs or steroids. Demographic data were recorded
and clinical examination was performed by a rheumatologist. Joint ultrasound of
the 3 most painful and / or swollen joints was performed in B-mode and Doppler
power research, looking for subcutaneous infiltration, effusion, tenosynovitis,
erosion and Doppler signal.

Results: 28 patients were enrolled, including 19 women and 9 men with a
mean age of 50.75 years and mean diseases duration of 6.15 days.

At baseline, all patients had arthritis, 18 patients had fatigue, 12 had myalgia 
and 3 had a fever.

Mean VAS  was 38.7,
the average number of painful joints was
6.2 and the average number of swollen joints was 3.3.

Joint effusion and /or synovial hypertrophy  were present in
92.8% of studied joints, with hand and wrist in 75%, ankle 50%, knees 35.7%,
mostly unilateral (in 75% of cases). A positive Doppler signal was found in
28.3% of effusions.

Tenosynovitis were
found in 2 patients only
(unilateral in 1, bilateral in 2). None had erosion
at that early visit.

Subcutaneous infiltration with ankles periarthritis
was present in 28.6% of patients, unilateral in 3 and bilateral in 5.

2/28 patients with a confirmed diagnosis of
CHIK had a normal ultrasound examination.

Conclusion: Ankle periarthritis has been described during acute sarcoïdosis in association with erythema nodosum. It’s the first time ankle periarthritis
is described with another acute arthritis. In epidemic situation of CHIK this
finding may help the clinician diagnosis.

We describe for the first time ankle periarthritis as a new sign for acute Chik
arthritis.