Hives are often caused when the body releases a chemical called histamine. Histamine is released during an allergic reaction. Many people, though, get hives without being exposed to something they are allergic to.
While the cause is unknown in some cases, these factors may cause hives:
- Foods, most commonly:
- Fresh berries
- Reaction to allergy shots
- Insect bites or stings
- Cold or heat
Underlying medical conditions:
- Vasculitis (inflammation of the blood vessels)
- Thyroid disease—hypothyroidism or hyperthyroidism
- Some cancers, such as lymphoma
- Viral infections, such as HIV infection, hepatitis, and cytomegalovirus
You will be asked about your symptoms and medical history. A physical exam will be done. You may need to see a doctor who specializes in skin disorders (dermatologist) or allergies (allergist).
Your bodily fluids and tissues may be tested. This can be done with:
- Blood tests
- Skin prick test
- Skin biopsy
Images may be taken of your bodily structures. This can be done with x-rays.
The best way to treat hives is to find and then avoid the cause.
If the cause cannot be found, there are medicines to reduce symptoms or treat hives:
- Leukotriene antagonists
- Oral steroid medications for hives resistant to other treatments
- Anti-inflammatory medicines
- Immunosuppressant medicines
- Ultraviolet light therapy
- Prescription epinephrine (adrenalin) injections for cases when swelling affects the airways
This content is reviewed regularly and is updated when new and relevant evidence is made available. This information is neither intended nor implied to be a substitute for professional medical advice. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with questions regarding a medical condition.
Edits to original content made by Denver Health.
Copyright © EBSCO Information Services
All rights reserved.
a (Angioedema; Urticaria)
American Academy of Allergy, Asthma & Immunology http://www.aaaai.org
American Academy of Dermatology https://www.aad.org
Allergy Asthma Information Association http://aaia.ca
Calgary Allergy Network http://www.calgaryallergy.ca
Acute urticaria. EBSCO DynaMed website. Available at: https://www.dynamed.com/condition/acute-urticaria . Updated July 27, 2017. Accessed October 2, 2017.
Allergic skin conditions. American Academy of Allergy, Asthma & Immunology website. Available at: http://www.aaaai.org/conditions-and-treatments/library/at-a-glance/allergic-skin-conditions. Updated October 2, 2017.
Chronic urticaria. EBSCO DynaMed website. Available at: https://www.dynamed.com/condition/chronic-urticaria . Updated July 27, 2017. Accessed October 2, 2017.
Dibbern DA Jr. Urticaria: selected highlights and recent advances. Med Clin North Am. 2006;90(1):187-209.
Gambichler T, Breuckmann F, Boms S, Altmeyer P, Kreuter A. Narrowband UVB phototherapy in skin conditions beyond psoriasis. J Am Acad Dermatol. 2005;52(4):660-670.
Guldbakke KK, Khachemoune A. Etiology, classification, and treatment of urticaria. Cutis. 2007;79(1):41-49.
Hives. American Academy of Dermatology website. Available at: https://www.aad.org/public/diseases/itchy-skin/hives. Accessed October 2, 2017.
Kaplan Allen P. Chronic urticaria: pathogenesis and treatment. J Allergy Clin Immunol. 2004;114(3): 465-474.