A systematic review including 4 RCTs with a total of 303 subjects was abstracted in DARE. One trial yielded equivocal results. The remaining three trials reported that after 3 to 4 weeks, paraffin wax applications were accompanied by significant improvements in rheumatoid arthritic hand function when followed by exercise. Paraffin wax also relieved pain and stiffness immediately after its application, with no documented detrimental effects on the disease process, even though paraffin wax temporarily raises joint temperature.
Comment: No reliability estimates were forthcoming for any of the documented outcome measures. In addition, no standard deviations were reported, and no effective standardisation of the cointerventions was established.