RxMed: Illness Information

Valuable information for over 200 common illnesses

General Illness Information

Common Name:

Hives

Medical Term:

Urticaria

Description:

Disorder characterized by a skin rash with raised areas with redness and itching. Commonly allergic but may also occur on a non-allergic basis.

Causes:

Allergic or non-allergic; massive histamine release from mast cells in skin.

· Drug reaction especially Aspirin, Non-steroidal anti- inflammatory drugs.

· Food or food additive allergy

· Allergy to peanuts and/or tree nuts a leading cause of severe (sometimes fatal) food-induced allergic reactions. Affects 1% of the general population. Other foods that cause hives are chocolate, fish, tomatoes, eggs, fresh berries, milk. Also food additives and preservatives.

· Inhalant, contact allergy

· Transfusion reaction

· Insect bite, sting

· Infection - viral upper respiratory infections (esp. in children) and infectious mononucleosis, viral hepatitis; bacterial (strep throat, sinusitis, dental abscess, otitis); vaginitis; fungal ; helminthic; protozoan. Helicobacter pylori has been increasingly associated with, and its eradication may stop, chronic urticaria.

· Collagen vascular disease (cutaneous vasculitis, serum sickness, lupus)

· Thyroid autoimmunity often associated. Administering thyroid hormone may alleviate chronic urticaria in hypothyroid patients with autoantibodies.

· Physical trauma (heat, cold, sunlight, etc.)

· Emotional stress.

Prevention:

If you have had hives and identified the cause, avoid the source.

Keep an anaphylaxis kit if you experience severe reactions.

Signs & Symptoms

Itchy skin papules (small, raised bumps) with the following characteristics:

They swell and produce pink or red lesions called wheals. Wheals have clearly defined edges and flat tops. They measure 1 cm to 5 cm in diameter.

Wheals join together quickly and form large, flat plaques (larger areas of raised, skin-colored lesions).

Wheals and plaques change shape, resolve and reappear in minutes or hours. This rapid change is unique to hives.

Risk Factors

Diagnosis & Treatment

This is a clinical diagnosis. Laboratory studies not usually helpful.

General Measures:

Emergency room care for life threatening reactions like difficulty swallowing, talking or breathing.

Laboratory studies are not usually helpful in the evaluation of acute or chronic reactions unless there are suggestive findings in the history and physical examination.

Cause of chronic reaction is rarely found.

Treatment aims are to prevent contact with the triggering factors.

Allergy skin tests are usually not helpful.

Desensitization injections are useful only when a specific allergen is found on skin testing .

Don't take drugs (including aspirin, laxatives, sedatives, vitamins, antacids, pain killers or cough syrup) not prescribed for you.

Don't wear tight underwear or foundation garments. Any skin irritation may trigger new outbreaks.

Hot baths or showers may aggravate the condition..

Apply cold-water compresses or soaks to relieve itching.

Using colloidal oatmeal in a tepid bath may help relieve the itching.

Medications:

Mainstay of treatment is antihistamines. Sometimes combination of antihistamines will be more helpful.

For rapidly progressing acute urticaria subcutaneous injection of epinephrine is used.

Corticosteroids may sometimes need to be prescribed for a severe acute reaction.

Tricyclic antidepressants appear to be effective in some cases of chronic urticaria.

Activity:
As desired. Avoid overheating.

Diet:
	As desired. Avoid foods implicated as possible etiologic agents

Possible Complications :
	Severe systemic allergic reaction (bronchospasm, anaphylaxis)

Prognosis

Of all patients with acute urticaria, 70% will be better in < 72 hours. 30% will become chronic.

20% have attacks for > 20 years.