Uncategorized • May 20, 2010

Hives

 
 Hives, or urticaria, can be acute or chronic. Acute urticaria is a common, allergic skin disorder characterized by well- circumscribed localized or generalized raised pink lesions (wheals or welts) of various sizes. It usually is a very itchy rash. Chronic urticaria is a type of urticaria that recurs or lasts longer than 6 weeks.

Causes:
· Ingestions (usually foods like sea foods, nuts, eggs food additives;  antibiotics like penicillin and sulfa drugs)
· Direct contact (plants like Poison Ivy, Poison Oak, Poison Sumac)
· Injected  agents (medicines, blood products, insect bites and stings)
· Inhalants (pollens, dander etc.)
· Infections (viral like Hepatitis, some bacterial and parasitic)
· Physical factors (cold, pressure, sun exposure)
· Systemic Illness (like malignancy, serum sickness )
· Associated with anaphylaxis or angioedema
· Rarely hereditary (cold urticaria)

Course:
· More than 10% of children get hives.
· Most children who develop hives have it only once. These hives usually come and go for 3 to 4 days and then resolve.
· If hives occur around the eyes, lips or genitals, it may cause large swelling. Some young children who become sensitized to insect bites may develop big hives called papular urticaria at the site of the insect bites that can sometimes last for up to months.
· Hives are usually self limited and benign with a good prognosis. They usually need only symptomatic treatment.
·  Chronic urticaria may persist intermittently for months to years and need further investigation.
Complications:
· It is important to watch for any potential life threatening complications that are rarely associated with urticaria. Swelling of the upper airways can be dangerous.
· Progression to anaphylaxis with wheezing and hypotension may also be life threatening.
Treatment:
· The best drug for hives is an antihistamine. It will not cure the hives but it will reduce the number of hives and the itching. Benadryl, one of the commonly used antihistamines is available over the counter. Give the appropriate weight based dosage indicated on the bottle every 6 hours. The most common side effect of this drug is drowsiness.
· Calamine or Caladryl lotion applied to the hives can help with the relief of itching. Cool baths or rubbing ice cubes briefly can also help with the itching.
· Avoidance of the possible trigger is the best approach. For hives trigger by pollen or animal contact, take a cool shower. For localized contact, wash the allergic substance off the skin with soap and water. Small localized hives usually disappear in a few hours and do not need Benadryl.
· Rarely, for severe urticaria, oral steroids maybe prescribed by your doctor.

Seek immediate medical care:
· For hives or rash that is worsening or spreading.
· If the rash looks infected.

 

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