Infections - Overview

Viral Infections

Bacterial Infections

  • A virus consists of a core of nucleic acid (DNA or RNA) surrounded by a coat of antigenic protein.
  • The virus provides the genetic code for replication, whereas the host cell provides the energy and raw material for the virus to grow.
  • Bacteria are single cell organisms that do not have a nucleus and are among the most simple and most
    abundant life forms on earth.
  • antibiotics are effective against bacterial infections, not viruses.
  • Bacteria grow OUTSIDE the host cell and can be attacked by antibiotics

Common Conditions



What causes blepharitis?

Blepharitis occurs in two forms:

  1. Anterior blepharitis Posterior blepharitis
    1. affects the outside front of the eyelid, where the eyelashes are attached.
    2. two most common causes of anterior blepharitis are
    3. bacteria (Staphylococcus)
    4. scalp dandruff.

What are the symptoms of blepharitis?

What other conditions are associated with blepharitis?



Allergic Conjuctivitis


Seasonal allergic conjunctivitis affects people during specific seasons of the year while perennial allergic conjunctivitis impacts people throughout the year. Allergic conjunctivitis can cause much discomfort due to the symptoms listed above. In adds to, untreated allergic conjunctivitis might cause someone to often rub his/her eyes, which could lead to permanent eye damage.


Allergic Conjunctivitis Causes

Pollen – Pollen is released by trees, weeds, and grasses, and is propelled by the wind. Pollen affects those with allergic conjunctivitis by entering the throats and noses of those who are sensitive to the substance. Pollen levels are at the highest during the spring and fall months. Pollen is considered one of the hardest causes of allergic conjunctivitis to control. Some common types of pollen include, ragweed, cedar and ash.

Mold – Another main cause of allergic conjunctivitis is mold. When inhaled, minuscule fungal spores can instigate allergy eyes. Mold usually impacts those who are susceptible between spring and late fall. Cold temperatures and snow diminish the mold spores count, yet they are still present after frost begins. Mold spores are found in leaves, hay, and grasses.

Pets – The dander, saliva, urine, and hair from household pets are other major causes of allergic conjunctivitis. Dander are tiny scales that shed off of cats and dogs. Although it is commonly thought that the actual hairs of pets are the causes of allergic conjunctivitis, this belief is inaccurate. The hair/fur of a pet itself is not one of the causes of allergic conjunctivitis, but the hair/fur can collect dander, mold, pollen, dust, each of which cause the condition.

Dust Mites – Dust mites are minute bugs that are one of the fundamental causes of allergic conjunctivitis. Dust mites can be found on the sofas, curtains, bed sheets, and other such places within the home. By often vacuuming and washing bed sheets one can reduce the number of dust mites in the home.

Causes of Allergic Conjunctivitis - Other Allergens

Beyond the causes of allergic conjunctivitis mentioned above, there are several other allergens that can cause the condition. These include: