Treatments as described above can be effective in reducing the frequency and degree of effusions. Deformative changes to joints are not a common feature of this mostly non-inflammatory condition. Epidemiology
Intermittent hydrarthrosis is uncommon and its prevalence is not known. (In 1974 more than 200 cases were reported in published literature). It affects men and women equally although some publications suggest the condition is slightly more prevalent in females. Case reports indicate that only white people are affected. First onset of IH is most common between the ages of 20 and 50 years, and in females, onset can often coincide with puberty.Usually the condition begins spontaneously or following trauma to the joint in otherwise healthy individuals. History
Perrin (France) is reported to have first recorded this condition in 1845. The periodic nature of infusions was noted by CH Moore (Middlesex Hospital, UK) in 1852. When the condition was first being reported in scientific journals, IH was classified as either ‘symptomatic’ or ‘idiopathic’ (of unknown cause). The symptomatic state was associated with existing disease such as rheumatoid arthritis, ankylosing spondylitis, other arthritis, or infection e.g. Brucellosis. With the idiopathic variant, an allergic component was believed to be involved since, in some patients at least, allergic phenomena (including cases of angioedema) were associated with episodes of inflammation.
More aggressive treatments such as synovectomy, achieved using intra-articular agents (chemical or radioactive) can provide good results, with efficacy reported for at least 1 year.Reducing acute joint swelling:
Arthrocentesis (or drainage of joint) may be useful to relieve joint swelling and improve range of motion. Local steroid injections can also reduce fluid accumulation short-term, but do not prevent onset of episodes. These treatments provide temporary relief only. Bed rest, ice packs splints and exercise are ineffective.A single case report of a patient with treatment-refractory IH describes the use of anakinra, an interleukin 1 receptor antagonist. At the first sign of any attack, a single 100 mg dose was given. With this dosing at onset of attacks, each episode of effusion was successfully terminated.Reducing frequency and severity of IH episodes:
Case reports indicate some success using long-term, low-dose colchicine (e.g. 0.5 mg to 1 mg daily). A recent single case report has shown hydroxychloroquine (300 mg daily) to be effective too.Small-sized clinical trials have shown positive results with (1) chemical and (2) radioactive synovectomy. (1) Setti et al. treated 53 patients with rifampicin RV (600 mg intra-articular injections weekly for approximately 6 weeks) with good results at 1 year follow-up. (2) Top and Cross used single doses of intra-articular radioactive gold in 18 patients with persistent effusions of mixed causes including 3 with IH. All 3 patients with IH responded well to treatment at one-year follow-up. Prognosis
Once established, periods of remissions and relapse can persist indefinitely. While IH may remit spontaneously for most people the condition is long-lasting.