Asthma treatment should be optimized in patients continuing having poor symptom control and/or exacerbations, even though Step 4 and Step 5 treatments and contributing factors should be assessed, in order to treat modifiable risk factors that compromise disease stability (smoking, environmental exposures, allergen exposure (if sensitized on skin prick testing or specific IgE), and medications such as beta-blockers and NSAIDs) (Table 5). Here, IGHE is linked to asthma.