Erosive hand osteoarthritis is a form of hand osteoarthritis. Phase of the normal process or separate entity? This remains debated. It is defined by radiographic erosions with a central subchondral bone collapse. It is more frequent than initially described as recently evidenced by ultrasonographic and MRI images which have shown better sensitivity to detect erosions and osteophytes than conventional radiographs. Synovitis, detectable by Doppler ultrasonography, is a common feature. The classical clinical picture is made of inflammatory flares with severe pain, joint swelling and important functional impairment. It leads to severe joint destruction, with major deformations and sometimes ankylosis with mobility restriction. It carries high consequences in terms of aesthetic discomfort, functional impairment and impact on quality of life, justifying the earliest diagnosis as possible and a tight management using, among many other options, local and general anti-inflammatory therapeutics.