Background Chikungunya is an arthritogenic mosquito-borne virus causing an epidemic in the Caribbean and Central America. Fever, rash and diffuse, incapacitating polyarthralgia characterise acute infection, which may be followed by persistent arthralgia, often causing significant impairment. Most rheumatologists will have seen very few, if any cases. The extent of joint pathology has not been well defined and there are little data to guide treatment.
Objectives To describe the cohort of patients with chikungunya infection at University College London Hospital (UCLH), to use ultrasound to define the joint abnormalities and to assess a systematic treatment approach.
Methods Records of patients seen at UCLH with proven chikungunya infection between August 2014 and January 2015 were reviewed. A tropical diseases-rheumatology clinic was set up to assess patients with persistent arthralgia, using clinical examination, DAS-28, targeted MSK ultrasound and investigation for alternative diagnoses. Treatment was commensurate with symptoms, ultrasound findings and prior therapy. Follow-up assessed clinical progress and the need for treatment escalation.
Results Between August 2014 and January 2015, 54 patients with proven chikungunya infection were seen, compared to 5 patients had in the same period 12-months previously. 21 patients were seen in the tropical diseases–rheumatology clinic. 65% of patients were female, mean age was 50.5 years. 50 (93%) had travelled to the Caribbean. The median time between symptom onset and first review was 25 days (range 1-261 days), with initial illness manifest by diffuse arthralgia (93%), fever (72%), rash (52%), fatigue (20%), and headache (19%). At presentation mean CRP was 7.1mg/L (range <0.6-55) and ESR 16.8 (2-93 mm/h). 8 patients (15%) had a positive RF (range 14-242 IU/mL), but negative anti-CCP antibodies.
In the cohort with persistent arthrlagia, joints affected included knees (71%), feet (62%), ankles (57%), hands (57%), wrists (48%) and elbows (14%), with a mean DAS of 2.9 (range 0.42-5.0). 9 patients (43%) reported symptoms consistent with carpal tunnel syndrome. MSK ultrasound demonstrated effusions (90%), synovial hypertrophy (85%) and osteophytes (45%). Three patients had a grade 1 power Doppler. Bone erosion was not seen in any patient.
32 patients (59%) received NSAIDs and 5 (9%) steroids. One patient received chloroquine and sulphasalazine. Wrist splints were used for carpal tunnel syndrome. 83% of the total cohort and every patient in the specialist clinic had follow-up, at a median of 6.3 weeks (range 1-22 weeks), at which point 7% had improved, 83% were improving and 7% were unchanged. No patients deteriorated.
Conclusions Clinical manifestations in the current chikungunya outbreak are similar to those described previously, with arthralgia sometimes persisting for some months. Clinicians should enquire about symptoms of carpal tunnel syndrome. Ultrasound frequently demonstrated effusions and synovial hypertrophy, no patients had evidence of bone erosion. Most patients had persistent symptoms at follow-up, but only a minority with recalcitrant symptoms required systemic steroids or sulphasalazine. These findings should be used to reassure patients. Disease modifying agents should be considered in patients with ongoing symptoms despite NSAIDs and steroids.
Acknowledgements Mike Brown & Robin Bailey, Hospital for Tropical Diseases
Jane Osborne, Rare and Imported Pathogens Laboratory
Disclosure of Interest None declared