Urticaria, commonly referred to as hives, is the most frequent dermatologic disorder seen in the emergency department (ED).
It appears as raised, well-circumscribed areas of erythema and edema involving the dermis and epidermis that are very pruritic. A large variety of urticaria variants exist, including acute immunoglobulin E (Ig E)–mediated urticaria, chemical-induced urticaria (non-Ig E-mediated), autoimmune urticaria, cholinergic urticaria, cold urticaria, mastocytosis, periodic fever syndromes including Muckle-Wells syndrome, and many others.
To avoid or minimize the effect of histamines, antihistamines are used.
Antihistamines are the chemicals which block the receptors from binding with the histamines, and by doing this they inhibit the allergic reactions.
They're usually divided into two main groups: They also come in several different forms – including tablets, capsules, liquids, syrups, creams, lotions, gels, eye drops and nasal sprays.
There's not much evidence to suggest any particular antihistamine is better than any other at relieving allergy symptoms.
Most antihistamines can be bought from pharmacies and shops, but some are only available on prescription.
This page covers: Types of antihistamines How to take them Side effects Taking them with other medicines, food or alcohol Who can take them – including pregnancy advice How they work There are many types of antihistamine.
While the itch can be intense, the skin is usually not scabbed or broken. Hives are very common with 10-20 percent of the population having at least one episode in their lifetime.
Hives can sometimes occur in deeper tissues of the eyes, mouth, hands or genitals.
Non-drowsy antihistamines are generally the best option, as they're less likely to make you feel sleepy.
But types that make you feel sleepy may be better if your symptoms affect your sleep.
Urticaria may be confused with a variety of other dermatologic diseases that are similar in appearance and are pruritic including atopic dermatitis (eczema), maculopapular drug eruptions, contact dermatitis, insect bites, erythema multiforme, pityriasis rosea, urticarial vasculitis, and others.