Leukotriene antagonists
If there is no response to a higher dose of less-sedating antihistamine, or the patient does not tolerate the less-sedating antihistamine, change to a short-term trial of leukotriene antagonist (eg montelukast). However, if there is some response to a higher dose of less-sedating antihistamine but symptoms still persist, consider adding a short-term trial of leukotriene antagonist.
For urticaria, use:
montelukast1 montelukast montelukast montelukast
adult: 10 mg orally, daily
child 6 to 14 years: 5 mg orally, daily
child 2 to 5 years: 4 mg orally, daily.
If symptoms still persist, consider referring to a specialist (eg dermatologist, allergist, immunologist) for omalizumab and other specialist treatments. While waiting for specialist referral (or instead of specialist referral, if preferred), consider trialling a histamine H2-receptor antagonist and/or doxepin (in adults only) (either as an addition to existing therapy, or as an alternative to existing therapy).