Does inhaled corticosteroid treatment result in a secondary immune deficiency predisposing to recurrent infections?

It is well known that long-term treatment with systemic steroids exerts immune-suppressive effects on the cellular immune system and increase the susceptibility to all types of intracellular infections. Inhaled corticosteroids have been the mainstay treatment for asthma for a long period and are generally accepted as safe with no or minimal systemic absorption. Although, these medications are usually used for long periods and sometimes in high doses, there is scarce evidence on their impact on cell mediated immunity, reactivation of tuberculosis in tuberculin skin test positive patients, innate and anti-viral immunity. Hereby, the studies on immune-suppressive effects of inhaled steroids are discussed focusing on cell mediated and antiviral immunity.