With RA, small joints are mostly affected in an inflammatory, destructive manner. This is not observed in IH. Rheumatoid factor, cyclic citrullinated peptide antibodies and antinuclear antibodies are usually negative in IH. Palindromic rheumatism. Like IH, palindromic rheumatism (PR) is also characterised by relapsing, short-episodes of sudden onset arthritis with no recognisable trigger. However, unlike PR, IH affects the knee almost exclusively and there is a predictable periodic, regularity of attacks, with laboratory tests during attacks being generally unremarkable. PR is also more likely to be associated with development of rheumatoid arthritis. Familial Mediterranean Fever. For some patients with FMF, episodes of knee or joint inflammation may be the only presenting symptom during an acute inflammatory episode. The MEFV gene mutations associated with FMF have been implicated in the pathogenesis of both palindromic rheumatism and IH. Other conditions for consideration (or exclusion) are other periodic arthropathies, crystal arthopathy, prepatellar bursitis (housemaids knee), pigmented villonodular synovitis, trauma and infectious causes. Treatment
No treatment has been found to be routinely effective. NSAIDs and COX-2 inhibitors are not generally helpful other than for general pain relief. They do not seem to help reduce effusions or prevent their occurrence. Low-dose colchicine (and some other ‘anti-rheumatic’ therapies e.g. hydroxychloroquine) have been used with some success. (Use of methotrexate and intramuscular gold have not been reported in the literature).
Rheumatoid disease did not develop in this latter variant.Today, a primarily auto-immune cause predominates literature with speculation that IH may be an inherited conditionOn the basis that IH is periodic in its presentation, early researchers proposed links with malaria where symptoms are also cyclical, even though the two have different duration cycles. Treatment with quinine (and arsenic) compounds were trialled with little benefit. Links to other infectious disease have also been posited over the years. These included Brucella, gonorrhoea, and syphilis.Adrenaline injections, mercury, various hormone treatments (ovarian extracts, growth hormone, stilboestrol), and ergotamine tartrate are among other treatments at some time used without significant or long-term benefit. Physiotherapy, surgery, exclusion diets (following allergen testing) have similarly shown no particular success in early reports of IH. References


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