Topical therapy with 5% doxepin cream (Zonalon) or capsaicin may also be used in refractory cases.Cyproheptadine may be useful to suppress recurrent cold urticaria.Histamines encourage the body to rid itself of the allergen by triggering ways to flush the allergen, such as watery eyes, a runny nose and sneezing; if the skin is the affected area, the histamines may produce a rash as protection.Antihistamines block histamines, thereby preventing some or all of the allergen's effects, but early antihistamines often caused drowsiness.Antihistamines are classified into two groups – the first-generation (“sedating”) and second-generation (“non-sedating”).Sedating antihistamines cause sedation as they are highly lipid soluble and readily cross the blood brain barrier.By inhibiting the activity of histamine, they can reduce capillary fragility, which produces the erythema, or redness, associated with allergic reactions.
When the body comes into contact with something to which it is allergic, whether through contact, respiration or consumption, substances called histamines are released to attack the allergen.
The efficacy and safety of omalizumab for CIU was demonstrated in two clinical studies that showed omalizumab significantly improved the mean weekly Itch Severity Score (ISS) from baseline by 9.4-9.6 in the 300-mg treatment arm (The dosing for use in asthma is based on weight and Ig E levels, but omalizumab can be administered in 150- or 300-mg doses and, unfortunately, there are no clinical markers that can predict whether or not it will be effective.
Although the evidence supporting its efficacy in treating urticaria is of high quality, the cost of the drug may preclude its use in many patients.
On the other hand, some patients experience none of these symptoms when taking sedating antihistamines.
Because each patient can react differently, individuals should determine how they react to a non-sedating antihistamine before driving, taking important tests or operating dangerous machinery.