1. Department of Internal Medicine, Centro Hospitalar Universitário de Santo António, Porto, Portugal. analuisaviveiros@gmail.com
2. Department of Internal Medicine, Centro Hospitalar Universitário de São João, Porto, Portugal.
3. Department of Internal Medicine, Centro Hospitalar Universitário de Lisboa Norte, Porto, Portugal.
4. Centre for Rheumatology, Division of Medicine, University College of London, UK.