From the Guidelines

Inhaled corticosteroids are the best corticosteroid option for patients with asthma.

Inhaled corticosteroids are the most potent and consistently effective long-term control medication for asthma 1.
There are no clinically meaningful differences among the various types of inhaled corticosteroids 1.
The use of spacers (valved holding chambers) with metered dose inhalers can increase the percentage of the dose deposited in the lungs 1.
Systemic effects of inhaled corticosteroids may occur but are typically not clinically important, except with long-term use 1.
For patients who have asthma not sufficiently controlled with inhaled corticosteroids alone, the option to increase the dosage of inhaled corticosteroids should be given equal weight to the option of adding long-acting beta agonists to inhaled corticosteroids 1.

Inhaled corticosteroids are the preferred controller medication for persistent asthma, and studies have demonstrated that they improve asthma control more effectively than any other single long-term control medication 1.
Combining long-acting beta agonists and inhaled corticosteroids is effective and safe when inhaled corticosteroids alone are insufficient 1.
Oral systemic corticosteroids should be used to treat moderate to severe asthma exacerbations 1.
The dose of inhaled corticosteroids may be reduced 25% to 50% every 3 months to the lowest possible dose once asthma is well controlled for at least 3 months 1.

Smokers have a decreased responsiveness to steroids, possibly due to persistent irritation and scarring 1.
Black children may have an increased risk of corticosteroid insensitivity due to deficiencies in T cell pathways 1.
Patients with high levels of inflammation or reduced corticosteroid sensitivity may require alternative treatment options 1.

From the Research

Inhaled corticosteroids (ICS) are considered the cornerstone of asthma therapy and are the most effective anti-inflammatory medication for persistent asthma 2, 3.
For patients with mild persistent asthma, low-dose ICS are usually sufficient for control, while those with moderate persistent asthma may require a combination of ICS and a long-acting beta-agonist (LABA) 4.
Biologics such as omalizumab, mepolizumab, benralizumab, and dupilumab have been shown to reduce the need for oral corticosteroids (OCS) in severe asthma, while also reducing exacerbation rates and improving patient-related outcomes 5.
Systemic corticosteroids (SCS) are effective for acute exacerbations and long-term symptom control, but long-term use is associated with serious adverse effects, and SCS Stewardship strategies are needed to minimize harm 6.

ICS are more effective than leukotriene receptor antagonists (LTRAs) as initial maintenance therapy for persistent asthma, with greater improvements in lung function and asthma control 2, 3.
The combination of an ICS and LABA is preferred for patients with moderate persistent asthma, and is more effective than doubling or quadrupling the dose of ICS alone 4.
Biologics have been shown to be effective in reducing OCS use and improving outcomes in severe asthma, and may be considered as an alternative to SCS 5.

The use of SCS should be carefully evaluated, and benefits should be weighed against potential harms 6.
Patients receiving long-term SCS or frequent acute courses should be closely monitored for emergence of SCS-related adverse effects 6.
SCS Stewardship strategies, including primary prevention of exacerbations and improvement of asthma control, are needed to minimize harm from SCS use 6.