Hives (urticaria)
Urticaria, also known as hives, is a dermatological medical condition in which red itchy bumps form on the skin. Hives are usually caused by an allergic reaction to a food or medication. People with allergies are more prone to develop urticaria; stress and infections can also cause it.[1] Physical exercise may also cause hives.[2]
Symptoms
Itching and the formation of red welts, called wheals, typify hives. The wheals have clearly defined edges and appear individually or eventually group together forming large reddish formations. A wheal when pressed in the center will turn white: this is called blanching. The wheals can disappear within minutes or remain for hours. "A hive often will go away in 24 hours or less, but bouts can last longer."[3]
Diagnosis
Physical examination
A healthcare provider can visually diagnose the presence of hives, and tests can determine whether the cause is an allergy.
The presence of angioedema is important.
Laboratory tests
Laboratory tests are rarely helpful.[4] Clinical practice guidelines vary in their recommendations:
- Joint Task Force on Practice Parameters: Complete blood count, urinalysis, liver function tests, erythrocyte sedimentation rate, and thyroid-stimulating hormone[5]
- British Association of Dermatologists: complete blood count, erythrocyte sedimentation rate[6]
If patients only have angioedema, C1 esterase inhibitor may be measured.
Treatment
No treatment may be needed for mild hives. Patients can take an antihistamine such as diphenhydramine to help reduce the itching and swelling. Patients who have throat swelling due to hives may receive epinephrine (adrenaline) or steroids. In some severe cases those same medications may be used to treat the condition.
For chronic urticaria, omalizumab is a "an anti-IgE; a recombinant humanised monoclonal antibody which specifically binds to the C epsilon3 domain of immunoglobulin (Ig) E, the site of high-affinity IgE receptor binding"[7]that may help.[8]
Potential complications
Complications include anaphylaxis and swelling in the throat.[9]
References
- ↑ Hives (Urticaria). Retrieved on 2011-06-01.
- ↑ Hives and Exercise–What It Means and What to Do. Am Fam Physician. 2001 Oct 15;64(8):1374.. Retrieved on 2011-06-02.
- ↑ Hives: Diagnosis, treatment, and outcome. Retrieved on 2011-06-01.
- ↑ Tarbox JA, Gutta RC, Radojicic C, Lang DM (2011). "Utility of routine laboratory testing in management of chronic urticaria/angioedema.". Ann Allergy Asthma Immunol 107 (3): 239-43. DOI:10.1016/j.anai.2011.06.008. PMID 21875543. Research Blogging.
- ↑ Joint Task Force on Practice Parameters (2000). "The diagnosis and management of urticaria: a practice parameter part I: acute urticaria/angioedema part II: chronic urticaria/angioedema. Joint Task Force on Practice Parameters.". Ann Allergy Asthma Immunol 85 (6 Pt 2): 521-44. PMID 11190256. [e]
- ↑ Grattan C, Powell S, Humphreys F, British Association of Dermatologists (2001). "Management and diagnostic guidelines for urticaria and angio-oedema.". Br J Dermatol 144 (4): 708-14. PMID 11298527. [e]
- ↑ Anonymous (2024), omalizumab (English). Medical Subject Headings. U.S. National Library of Medicine.
- ↑ Saini S, Rosen KE, Hsieh HJ, Wong DA, Conner E, Kaplan A et al. (2011). "A randomized, placebo-controlled, dose-ranging study of single-dose omalizumab in patients with H(1)-antihistamine-refractory chronic idiopathic urticaria.". J Allergy Clin Immunol 128 (3): 567-573.e1. DOI:10.1016/j.jaci.2011.06.010. PMID 21762974. Research Blogging.
- ↑ Berman, Kevin. Hives. Retrieved on 2011-06-01.