Is a Diet Necessary When Corticosteroid Treatment is Prescribed?

Inclusion criteria : * Age \> 18 years * All patients for whom corticoids initially prescribed at a dose \> 20 mg per 24 hours, during a period of 3 months minimum * Corticotherapy should be prescribed per os and continuously. (Alternating doses of corticoids, sequential intramuscular or intravenous injection of corticoids are not allowed in this clinical trial) * All diseases requiring corticotherapy may be subject to this clinical trial. The main pathologies will be systemic autoimmune diseases, asthma or chronic skin diseases justifying prolonged oral corticotherapy. * Time between first corticoids delivery and randomization \< 1 month * Patient who gave his non-opposition Note: Depending on their health condition, patient may receive one or more intravenous injections of methylprednisolone (until 3 injections), before the beginning of oral corticotherapy. Exclusion criteria : * Age \< 18 years or whose disability warrants a guardianship * All patients for whom corticoids prescribed \<20 mg per 24 hours or for an expected period \<3 months * Intramuscular or intravenous sequential corticoids delivery, without associated per os corticoids. * Any corticotherapies other than prednisone, prednisolone or methylprednisolone. * Any corticotherapies with alternating doses * Intravenous or intramuscular injection corticotherapy * Patient who received corticoids at a dose \>20 mg / day, during 3 last years * Allergy, hypersensitivity or cons-indication to corticoids * The existe…