Sunday, May 1, 2011

Pink Eye (Conjunctivitis)

What is "pink eye"?

Pink eye, or conjunctivitis, is redness and inflammation of the membranes (conjunctiva) covering the whites of the eyes and the membranes on the inner part of the eyelids. These membranes react to a wide range of bacteria, viruses, allergy-provoking agents, irritants, and toxic agents, as well as to underlying diseases within the body. Viral and bacterial forms of conjunctivitis are common in childhood, but they occur in adults as well. Pink eye can occur in people of any age. Overall, however, there are many causes of pink eye. These can be classified as either infectious or noninfectious. Pink eye does not cause any changes in vision.

What infections cause pink eye, what are infectious pink eye symptoms, and how are they treated?

Viral pink eye

The leading cause of a red, inflamed eye is virus infection. Adenoviruses are the type of virus that are most commonly responsible for the infection. Viral pink eye symptoms are usually associated with more of a watery discharge that is not green or yellow in color. Often, viral "cold-like" symptoms, such as sinus congestion and runny nose, are also present. The eyelids may be swollen. Sometimes looking at bright lights is painful.

While viral pink eye may not require an antibiotic, those affected should see a doctor, as occasionally this form of pink eye can be associated with infection of the cornea (the clear portion of the front of the eyeball). This infection must be correctly detected and treated. Viral pink eye is highly contagious. The symptoms of viral pink eye can last one to two weeks. Symptoms are pronounced for the first three to five days after symptoms appear, with slow resolution over the following one to two weeks.

Bacterial pink eye

Staphylococci and Streptococci, among others, are types of bacteria that commonly cause pink eye. Symptoms of bacterial pink eye include

  • eye pain,


  • swelling,


  • redness,

  • a moderate to large amount of discharge, usually yellow or greenish in color.

The discharge commonly accumulates after sleeping. Affected children may awaken most unhappy that their "eyes are stuck shut," requiring a warm washcloth applied to the eyes to remove the discharge. Bacterial pink eye is treated by repeated warm washcloths applied to the eyes (try applying these to your child's eye one eye at a time during a favorite video) and requires antibiotic eyedrops or ointment prescribed by the doctor.

Picture of Pink Eye or Conjunctivitis
What does pink eye look like?

Be careful not to use medication prescribed for someone else, or from an old infection, as these may be inappropriate for your current infection or may have been contaminated from other infections by accidentally touching the medicine bottle to infected areas. A safe, effective, and potentially less frightening method of putting drops into the eyes involves asking your child to lie down flat, with instructions to merely "close your eyes," and placing the recommended number of drops in the inner corner of the eye, next to the bridge of the nose, and letting them make a little "lake" there. When your child relaxes and opens the eyes, the medicine will flow gently into the infected mucous membranes without the need to "force open" the eyes.

When you feel that you or your child might have bacterial pink eye, it is very important to see your doctor immediately for several reasons. First, if the cause is a bacterial infection, an antibiotic will be needed to help the infection-fighting immune system to kill this infection. Secondly, if you are experiencing other symptoms such as a runny nose, cough, earache, etc., there is a good chance that these symptoms are caused by the same bacteria, and an oral antibiotic may also be needed to treat this infection along with the antibiotic drops or ointment for the eyes. Finally, your doctor will want to exclude the possibility that the infection has spread to areas where the symptoms may not yet be recognizable.

Chlamydia pink eye

Pink eye due to infection with chlamydia is an uncommon form of bacterial pink eye in the U.S., but it is very common in Africa and Middle Eastern countries. Chlamydia can cause pink eye in adults and neonates. It is a cause of pink eye in adolescents and adults that can be sexually transmitted. Chlamydia pink eye is typically treated with erythromycin (E-Mycin, Eryc, Ery-Tab, PCE, Pediazole, Ilosone) or oral tetracycline (Sumycin), except in children less than 8 years of age, because of possible discoloration of the teeth.

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Hives (Urticaria & Angioedema)

What are hives (urticaria)?

Hives (medically known as urticaria) appear on the skin as wheals which are red, very itchy, smoothly elevated areas of skin often with a blanched center. They appear in varying shapes and sizes, from a few millimeters to several inches in diameter anywhere on the body.

It is estimated that 20% of all people will develop urticaria at some point in their lives. Hives are more common in women than in men. One hallmark of hives is their tendency to change size rapidly and to move around, disappearing in one place and reappearing in other places, often in a matter of hours. Individual hives usually last no longer than 24 hours. An outbreak that looks impressive, even alarming, first thing in the morning can be completely gone by noon, only to be back in full force later in the day. Very few, if any other skin diseases occur and then resolve so rapidly. Therefore, even if you have no evidence of hives to show the doctor when you get to the office for examination, he or she can often establish the diagnosis based upon the history of your symptoms. Because hives fluctuate so much and so fast, it is helpful to bring along a photograph of what the outbreak looked like at its worst.

Swelling deeper in the skin that may accompany hives is called angioedema. This swelling may be seen on the hands and feet, as well as the lips or eyes, that can be as dramatic as it is brief.

What causes hives?

Hives are produced when histamine and other compounds are released from cells called mast cells, which are normally found in the skin. Histamine causes fluid to leak from the local blood vessels, leading to swelling in the skin.

Hives are very common. Although they can be annoying, they usually resolve on their own over a period of weeks and are rarely medically serious. Some hives are caused by allergies to such things as foods, medications, and insect stings, but in the majority of cases, no specific cause for them is ever found. Although patients may find it frustrating not to know what has caused their hives, maneuvers like changing diet, soap, detergent, and makeup are hardly ever helpful in preventing hives and are not necessary for the most part.

Having hives may cause stress, but stress by itself does not cause hives.

In rare cases (some hereditary, others caused by bee stings or drug allergy), urticaria and angioedema are accompanied by a striking decrease in blood pressure (shock) and difficulty breathing. This is called anaphylaxis. Ordinary hives may be widespread and disturbing to look at, but the vast majority of cases of hives do not lead to life-threatening complications.

Pictures of hives
What does urticaria (hives) look like?
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ELISA Tests

What is ELISA?

ELISA is an abbreviation for "enzyme-linked immunosorbent assay."

What is an ELISA test?

An ELISA test uses components of the immune system and chemicals to detect immune responses in the body (for example, to infectious microbes). The ELISA test involves an enzyme (a protein that catalyzes a biochemical reaction). It also involves an antibody or antigen (immunologic molecules).

What is the use of an ELISA test?

ELISA tests are widely utilized to detect substances that have antigenic properties, primarily proteins (as opposed to small molecules and ions such as glucose and potassium). The substances detected by ELISA tests include hormones, bacterial antigens and antibodies.

How does an ELISA test work?

There are variations of the ELISA test, but the most basic type consists of an antibody attached to a solid surface. This antibody has affinity for (will latch on to) the substance of interest, for example, human chorionic gonadotropin (HCG), the commonly measured protein which indicates pregnancy. A mixture of purified HCG linked (coupled) to an enzyme and the test sample (blood, urine, etc) are added to the test system. If no HCG is present in the test sample, then only HCG with linked enzyme will bind. The more HCG which is present in the test sample, the less enzyme linked HCG will bind. The substance the enzyme acts on is then added, and the amount of product measured in some way, such as a change in color of the solution.

What are the advantages of ELISA?

ELISA tests are generally relatively accurate tests. They are considered highly sensitive and specific and compare favorably with other methods used to detect substances in the body, such as radioimmune assay (RIA) tests. They have the added advantages of not needing radioisotopes (radioactive substances) or a costly radiation counter (a radiation-counting apparatus).

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Eczema

What is eczema?

Eczema is a general term for many types of skin inflammation (dermatitis). The most common form of eczema is atopic dermatitis (sometimes these two terms are used interchangeably). However, there are many different forms of eczema.

Eczema can affect people of any age, although the condition is most common in infants, and about 85% of those affected have an onset prior to 5 years of age. Eczema will permanently resolve by age 3 in about half of affected infants. In others, the condition tends to recur throughout life. People with eczema often have a family history of the condition or a family history of other allergic conditions, such as asthma or hay fever. The nature of the link between these conditions is inadequately understood. Up to 20% of children and 1%-2% of adults are believed to have eczema. Eczema is slightly more common in girls than in boys. It occurs in people of all races.

Eczema is not contagious, but since it is believed to be at least partially inherited, it is not uncommon to find members of the same family affected.

What are the causes of eczema?

Doctors do not know the exact cause of eczema, but a defect of the skin that impairs its function as a barrier, possibly combined with an abnormal function of the immune system, are believed to be important factors. Studies have shown that in people with atopic dermatitis there are gene defects that lead to abnormalities in certain proteins (such as filaggrin) that are important in maintaining the barrier of normal skin.

Some forms of eczema can be triggered by substances that come in contact with the skin, such as soaps, cosmetics, clothing, detergents, jewelry, or sweat. Environmental allergens (substances that cause allergic reactions) may also cause outbreaks of eczema. Changes in temperature or humidity, or even psychological stress, can lead to outbreaks of eczema in some people.

What are eczema symptoms and signs in babies, children, and adults?

Eczema most commonly causes dry, reddened skin that itches or burns, although the appearance of eczema varies from person to person and varies according to the specific type of eczema. Intense itching is generally the first symptom in most people with eczema. Sometimes, eczema may lead to blisters and oozing lesions, but eczema can also result in dry and scaly skin. Repeated scratching may lead to thickened, crusty skin.

While any region of the body may be affected by eczema, in children and adults, eczema typically occurs on the face, neck, and the insides of the elbows, knees, and ankles. In infants, eczema typically occurs on the forehead, cheeks, forearms, legs, scalp, and neck.

Eczema can sometimes occur as a brief reaction that only leads to symptoms for a few hours or days, but in other cases, the symptoms persist over a longer time and are referred to as chronic dermatitis.

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