Hives

Urticaria or hives is a relatively common form of allergic reaction that causes raised red skin welts. Urticaria is also known as nettle rash or uredo. These welts can range in diameter from 5 mm (0.2 inches) or more, itch severely, and often have a pale border. Urticaria is generally caused by direct contact with an allergenic substance, or an immune response to food or some other allergen. Hives can also be caused by stress.

Contents

1 Misconception
2 Types
3 Treatments 
 
 
Misconception
Angioedema is a related condition where similar types of swelling occur in a lower layer of the skin, mouth or throat. It is not identical to urticaria. They may, however, occur together.
The rash derived from poison-ivy is commonly mistaken for urticaria. Poison-ivy is caused by urushiol toxin. This resin can be spread by contact, but it is easily washed off.

Types
Acute urticaria usually show up a few minutes after contact with the allergen and can last a few hours to several weeks. Food allergic reactions typically fit in this category. Common causes of reaction include consumption of shell fish, nuts, eggs, fish, acid derivitives, dye.
Chronic urticaria refers to hives that persists for 6 weeks or more. There are no visual differences between acute and chronic urticaria. Some of the more severe chronic cases have lasted more than 20 years.
Drug-induced urticaria has been known to result in severe cardiorespiratory failure. The anti-diabetic suphonylurea glimepiride (trade name Amaryl®), in particular, has been documented to induce allergic reactions manifesting as urticaria. Other cases include aspirin, penicillin, sulfonamides and anticonvulsants.
Physical urticarias is often categorized into the following.
Aquagenic: Reaction to water (rare)
Cholinergic: Reaction to body heat, such as when exercising or after a hot shower
Cold: Reaction to cold, such as ice, cold air or water
Delayed Pressure: Reaction to standing for long periods, bra-straps, belts
Dermographism: Reaction when skin is scratched (very common)
Heat: Reaction to hot food or objects (rare)
Solar: Reaction to direct sunlight (rare)
Vibration: Reaction to vibration (rare)
Adrenergic: Reaction to adrenaline / noradrenalin (extremely rare)

Treatments
Oral antihistamines provide a good solution for acute urticaria. The medication will reduce the itching and help the welts disappear. Antihistimines mainly reduce sensitivity. Short term side effects include drowsiness, while long term side effects can lead to a less responsive immune system. In the case of chronic urticaria, a combination of H1 (ie, Zyrtec, Allegra etc) and H2 (ie, Zantac) antihistamines usually helps in these cases where H1 antihistamines alone do not give any results.
Oatmeal baths and anti-pruritic lotions can also be used to relieve the itching.
Detox baths usually consist of aromatherapic remedies such as Epsom salt in combination with body oil and water at high temperatures for 20 minutes. The method essentially forces the skin to perspire and excrete any potential toxin. It is not recommended for individuals with heart conditions. Efficacy of detox baths is suspect at best.
Chem-Free Technique otherwise known as Organic technique is a new method proving to be very effective against chronic urticaria. It directly counters detergent residue chemical compounds by reducing toxicity levels in the body. In the United States this method has not been well-promoted, since treatments are historically prescription and insurance oriented. It is perhaps the safest among all treatments. The technique requires the patient to wear newly acquired clothes that have never come in contact with laundry detergent chemicals. The clothes collection do include bed sheets and bath towels, which must all be washed with cold-water long rinse cycles and high volumes of baking soda NaHCO3. Clothes must also be hung dry to eliminate heat combustion with existing chemical residue in dryer. The patient's skin can only come in contact with the chemical-free clothes for the entire duration of 8-10 weeks. There should be a noticeable immune system boost after 4-6 weeks, followed by significant reduction if not complete elimination in hives count. This method has been proven to work for individuals suffering as much as 5 years of chronic urticaria.
Frequent use of moisturizers on the skin will add an extra layer of protection.