Urticaria is a common mast cell-mediated dermatosis presenting with pruritic erythematous superficial plaques also known as hives or wheals. Angioedema is an acute condition manifesting as localized edema affecting the skin and mucous membranes. In contrast with urticaria, itching is often absent, the skin appears normal and the edema occurs in deeper dermal and subcutaneous tissues in angioedema. Spontaneous urticaria can either be acute lasting less than 6 weeks or chronic with a duration of more than 6 weeks. In acute urticaria cases, an underlying cause, mostly medications, foods and infections, may be found in approximately 50% of patients. However, spontaneous urticaria is generally idiopathic. First-line treatment option for both acute and chronic urticaria is non-sedating H 1 antihistamines. Patients with recalcitrant disease are candidates for therapy with corticosteroids, immunosuppressives or omalizumab treatment. There are two different mechanisms causing angioedema. The first is mast cell mediated and is considered to be part of the spectrum of spontaneous or inducible urticarias. Patients present with angioedema alone or angioedema combined with urticaria. The second is bradykinin-induced angioedema, as observed in the hereditary angioedema and angiotensin-converting enzyme (ACE) inhibitor-induced angioedema.