Urticaria

Urticaria  is a kind of skin rash notable for pale red, raised, itchy bumps. Hives is frequently caused by allergic reactions; however, there are many non-allergic causes. Most cases of hives lasting less than six weeks (acute urticaria) are the result of an allergic trigger. Chronic urticaria (hives lasting longer than six weeks) is rarely due to an allergy. The majority of patients with chronic hives have an unknown (idiopathic) cause. Perhaps as many as 30–40% of patients with chronic idiopathic urticaria will, in fact, have an autoimmune cause. Acute viral infection is another common cause of acute urticaria (viral exanthem). Less common causes of hives include friction, pressure, temperature extremes, exercise, and sunlight.

Wheals (raised areas surrounded by a red base) from urticaria can appear anywhere on the surface of the skin. Whether the trigger is allergic or non-allergic, there is a complex release of inflammatory mediators, including histamine from cutaneous mast cells, resulting in fluid leakage from superficial blood vessels. Wheals may be pinpoint in size, or several inches in diameter. Angioedema is a related condition (also from allergic and non-allergic causes), though fluid leakage is from much deeper blood vessels. Individual hives that are painful, last more than 24 hours, or leave a bruise as they heal are more likely to be a more serious condition called urticarial vasculitis. Hives caused by stroking the skin (often linear in appearance) are due to a benign condition called dermographism.

Classification

Acute

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 often fit in this category.

Chronic

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. A survey indicated that chronic urticaria lasted a year or more in more than 50% of sufferers and 20 years or more in 20% of them.

Related conditions

Angioedema is similar to urticaria,but in angioedema, the swelling occurs in a lower layer of the dermis than it does in urticaria, as well as in the subcutis. This swelling can occur around the mouth, in the throat, in the abdomen, or in other locations. Urticaria and angioedema sometimes occur together in response to an allergen and is a concern in severe cases as angioedema of the throat can be fatal.

Cause

Many different substances in the environment may cause urticaria including: medications, food and physical agents.

Diet

The most common food allergies in adults are shellfish and nuts. The most common food allergies in children are shellfish, nuts, peanuts, eggs, wheat, and soy. It is uncommon for patients to have more than 2 true food allergies. A less common cause is exposure to certain bacteria, such as streptococcus or possibly Helicobacter pylori.

Physical agents

A number of physical urticarias include

 Aquagenic: Reaction to water (exceedingly rare)

 Cholinergic: Reaction to body heat, such as when exercising or after a hot shower

 Cold (Chronic cold urticaria): Reaction to cold, such as ice, cold air or water – worse with sudden change in temperature

 Delayed Pressure: Reaction to standing for long periods, bra-straps, elastic bands on undergarments, belts

 Dermatographic: Reaction when skin is scratched (very common)

 Heat: Reaction to hot food or objects (rare)

 Solar: Reaction to direct sunlight (rare, though more common in those with fair skin)

 Vibration: Reaction to vibration (rare)

 Adrenergic: Reaction to adrenaline / noradrenaline (extremely rare)

Other

Urticaria can be a complication and symptom of a parasitic infection as fascioliasis (Fasciola hepatica) and ascariasis (Ascaris lumbricoides).

The rash that develops from poison ivy, poison oak, and poison sumac contact is commonly mistaken for urticaria. This rash is caused by contact with urushiol and results in a form of contact dermatitis called Urushiol-induced contact dermatitis. Urushiol is spread by contact, but can be washed off with a strong grease/oil dissolving detergent and cool water and rubbing ointments.

 

Treatment

Treatment may not be needed if the hives are mild. They may disappear on their own. To reduce itching and swelling:

 Avoid hot baths or showers.

 Avoid irritating the area with tight-fitting clothing.

 Take antihistamines. Diphenhydramine is considered the most effective.

If your reaction is severe, especially if the swelling involves your throat, you may require an emergency shot of epinephrine (adrenaline) or steroids. Hives in the throat can block your airway, making it difficult to breathe

The homeopathic treatment for Chronic Urticaria is promising. It is much advanced and more scientific as it is not aimed at relieving the symptoms but treat the disease at immunological level. The treatment plans thus designed is addressed towards correcting the immune system, in turn treating Urticaria from within.