[Various manifestations of calcium pyrophosphate-associated arthritis]. / De diverse uitingen van calciumpyrofosfaat-artritis.

In calcium pyrophosphate (CPP)-associated arthritis, deposits of calcium pyrophosphate lead to acute attacks of painful joint inflammation. The disease may present with signs of systemic inflammation such as fever, mimicking an infectious disease. Early recognition and treatment of this disease can prevent overdiagnosis and joint damage. In this article we describe three different patient cases of CPP-associated arthritis. The diversity of clinical presentation in CPP-associated arthritis can be of interest to different medical specialties who will occasionally encounter them in daily practice.

[Unexplained pain in the ankle and foot. Consider transient osteoporosis]. / Onbegrepen pijn van de enkel en voet. Denk aan voorbijgaande osteoporose.

Transient osteoporosis is an increasingly recognized condition that causes severe pain in weight-bearing joints and is characterized by otherwise unexplained bone-marrow oedema on MRI. We present two patients, a 40-year-old man and a 60-year-old woman, with longstanding severe pain in the foot and ankle. Both had invalidating pain with only mild swelling of the foot or ankle. Laboratory investigation was unremarkable, and conventional X-ray showed osteopenia of the bones involved. In both cases, consecutive MRIs showed migrating bone marrow oedema. The patients were treated with analgesics, immobilization of the body parts concerned and an intravenous bisphosphonate.

[A man with swollen fingers]. / Een man met zwellingen van de vingers.

A 28-year-old man was referred to our hospital because of localised swelling of his fingers, with suspicion of arthritis of the proximal interphalangeal (PIP) joints. At physical examination we observed a swelling, superficial to the PIP joints. Ultrasonography revealed a hypo-echoic structure above the extensor tendon, typical for knuckle pads.