Question: Can a person get Cushing's from using steroid nasal sprays and inhalers? Do any of these interfere with cortisol testing for Cushing's?
 
Answer: Cushing's syndrome results from the effects of too much cortisol action. Cortisol action can be produced by a variety of steroids termed glucocorticoids. What is important is the levels of cortisol action, not how they were achieved. Thus, Cushing's syndrome can be caused by glucocorticoids given by mouth, injected into a joint, or administered topically to the skin or via inhalation. The synthetic steroids used in sprays and inhalers include: beclomethasone, triamcinolone, budesonide, flunisolide, and fluticasone and they are all much more potent than cortisol. Their ability to cause clinical symptoms depends upon the dose, duration of use, and amount of absorption into the blood stream. Although the levels achieved may be high enough to suppress one's own normal cortisol, the doses of these inhalers that are used in clinical practice are generally not high enough to produce clinically evident Cushing's syndrome and such cases are extremely unusual. However, systemic effects can still be observed, e.g. easy bruisability, and there is the potential for contributing to the development of osteoporosis, among other things. In general, the synthetic glucocorticoids used in nasal sprays and inhalers do not get measured in the up-to-date lab tests for cortisol, but there is still a possibility for interference with cortisol testing. Most individuals with Cushing's syndrome would not suppress their cortisol levels if they were to use steroid inhalers. However, there are always exceptions to every rule.