Acute Urticaria

Treatment: Goal is symptom control; lesions may or may not completely resolve with treatment.

- Education:

o Majority of cases resolve spontaneously [10]

o Review signs/symptoms that warrant further evaluation

- Non-sedating 2nd generation H1 receptor blocking anti-histamines are first line

treatment (cetirizine, fexofenadine, levocetirizine, loratadine, desloratadine)

o Preferred over 1st generation H1 antagonists (diphenhydramine,

chlorpheniramine, hydroxyzine) due to favorable side effect profile (less

sedating, fewer anti-cholinergic effects, less QT prolongation), less frequent

dosing, fewer drug-drug interactions [4, 24]

▪ Consider 1st generation H1 anti-histamine at bedtime, as urticaria

symptoms can be more bothersome at night

▪ No one agent has definitively been shown to be more effective; well-

controlled comparative studies lacking [4]

o Anti-histamines can be increased up to 4 times standard dosing (2 tablets BID

or 1 tablet QID) [4]

o Loratadine and cetirizine preferred in pregnant and lactating patients [25]

- May add on H2 antagonist (famotidine, cimetidine – caution with latter with respect

to drug-drug interactions)

- Systemic glucocorticoids: may consider brief course if symptoms extremely

bothersome and not responsive to above measures

o Not for prolonged treatment

o Consider concomitant GI prophylaxis

- Epinephrine autoinjector prescription is indicated in cases of suspected food-, venom-

or cold-induced urticaria, as these etiologies can involve anaphylaxis and accidental

exposure is possible

- Avoidance of triggers (when identified) is key

o One study noted anti-histamine premedication prevented NSAID reactions in

the majority of patients, though this approach is controversial [26]

Prognosis: 2/3 of cases resolve spontaneously [10]

Associated and Emerging Conditions:

- Hereditary alpha tryptasemia (HaT): individuals with this may present with urticaria;

this disorder also involved heightened risk of idiopathic anaphylaxis and severe

recurrent anaphylaxis (especially to venom)[33]