The recruited patients had a median (inter-quartile ranges) FENO level of 19 ppb (12-30 ppb). Patients with chronic cough had a significantly higher median FENO level than those with subacute cough ( vs 16 ppb; Z=-, P=). A FENO level ≥25 ppb was recorded in 15 (%) patients with subacute cough, as compared with 20 (%) in patients with chronic cough (χ(2)=, P=). With a FENO ≥25 ppb as the critical value to justify ICS treatment, 15 patients with subacute cough received ICS and 14 (%) of them showed obvious relief of cough after 2 weeks of therapy, a response rate similar to that of % (17/20) in patients with chronic cough receiving the treatment (χ(2)=, P=). In patients with subacute cough, those with cough variant asthma (CVA) or eosinophilic bronchitis (EB) had a significantly higher median FENO level than those with postinfectious cough [(16 (11-31) ppb vs 11 (8-19) ppb, P<]. In the etiological analysis, CVA or EB was identified in 23 (%) of the patients with subacute cough, as compared 21 (%) in patients with chronic cough (χ(2)=, P=).
Corticosteroids have been used as drug treatment for some time. Lewis Sarett of Merck & Co. was the first to synthesize cortisone, using a complicated 36-step process that started with deoxycholic acid, which was extracted from ox bile .  The low efficiency of converting deoxycholic acid into cortisone led to a cost of US $200 per gram. Russell Marker , at Syntex , discovered a much cheaper and more convenient starting material, diosgenin from wild Mexican yams . His conversion of diosgenin into progesterone by a four-step process now known as Marker degradation was an important step in mass production of all steroidal hormones, including cortisone and chemicals used in hormonal contraception .  In 1952, . Peterson and . Murray of Upjohn developed a process that used Rhizopus mold to oxidize progesterone into a compound that was readily converted to cortisone.  The ability to cheaply synthesize large quantities of cortisone from the diosgenin in yams resulted in a rapid drop in price to US $6 per gram, falling to $ per gram by 1980. Percy Julian's research also aided progress in the field.  The exact nature of cortisone's anti-inflammatory action remained a mystery for years after, however, until the leukocyte adhesion cascade and the role of phospholipase A2 in the production of prostaglandins and leukotrienes was fully understood in the early 1980s.
Inhaled corticosteroids are medications used to treat asthma. They are taken by using an inhaler. This medication should be taken consistently so that it decreases inflammation in the airways of your lungs and prevents asthma flare-ups. Inhaled corticosteroids are considered the most effective long term usage medication for control and management of asthma. Depending upon the severity of your asthma, your physician may combine an inhaled corticosteroid with a long-acting beta-2 agonist to treat your condition. Oral and intravenous corticosteroids may be required for acute asthma flare-ups or for severe symptoms.