This APP contains the therapeutic protocols developed and used by the Autoimmune Diseases Unit of the Department of Internal Medicine at Hospital Universitario Cruces (Osakidetza, Basque Health Service). It is aimed for clinicians of any specialty (Internal Medicine, Rheumatology, Dermatology, Nephrology, Hematology, Obstetrics, Pneumology...) looking after patients with systemic autoimmune diseases. Within this APP you will find a detailed description of topics such as glucocorticoid starting doses, tapering schedules, treatment duration, first and second-line thearpies and treatment options for refractory and relapsing disease. This is the first APP of this kind, it is free to download and available in Spanish, Basque and English languages. Our goal if providing clinicians with a simple and accessible tool, based on commonly used guidelines but also strongly reflecting our experience in routine clinical practice in real-world settings. It aims to be practical and detailed, in order to provide guidance on the management of most clinical scenarios involving patients with systemic autoimmune diseases.While taking into account all the diversity and complexity of this group of diseases, this APP is based on two main principles:1.- It is not necessary to use high doses of Prednisone in the treatment of patients with systemic autoimmune diseases. 2.- In general, use pulse Methylprednisolone and combine treatments in order to start with lower doses of Prednisone and rapidly taper-off. The APP Autoimmune is divided into the following sections:1.- GENERAL PRINCIPLES2.- GOOD USE OF DRUGS IN SYSTEMIC AUTOIMMUNE DISEASES • Antimalarials • Glucocorticoids • Immunosuppressive drugs • Immunoglobulins • Biological agents3.- GUIDE BY DISEASE • Temporal arteritis • Takayasu’s arteritis • IgG4-related disease • Behçet’s disease • Systemic sclerosis • Systemic lupus erythematosus • Inflammatory myopathies • Sarcoidosis • Antiphospholipid syndrome • Sjögren’s syndrome • Uveitis • ANCA-positive vasculitis4.- PREGNANCY AND AUTOIMMUNE DISEASESThe APP will be updated periodically whenever significant innovations in the treatment of systemic autoimmune diseases take place.