W. David Colby IV MSc MD FRCPC


Lyme Disease Rash

One symptom of Lyme disease is a red rash (called erythema migrans). The rash usually starts as a small red area and then expands over several days. The rash occurs at the site of the tick bite and usually gets bigger over time. Sometimes the rash clears in the center, so that it looks like a bull’s-eye. About half the…

Lyme Disease

Discusses Lyme disease, an infection spread by ticks. Includes info on deer ticks. Covers symptoms and Lyme disease tests. Covers treatment with antibiotics. Includes info on complications from not treating Lyme disease. Offers prevention tips.

Tuberculin Skin Test

A tuberculin skin test (also called a Mantoux tuberculin test) is done to see if you have ever been exposed to tuberculosis (TB). The test is done by putting a small amount of TB protein ( antigens ) under the top layer of skin on your inner forearm. If you have ever been exposed to the TB bacteria ( Mycobacterium…

Meningitis

Meningitis is inflammation of the tissues (meninges) that surround the brain and spinal cord. Meningitis is usually caused by an infection with bacteria or viruses.

Life Cycle of Malaria Parasites

You get malaria from a bite by an infected mosquito. This bite injects malaria-causing parasites into your blood, where they travel to liver cells. In the liver cells, the parasites breed. The cells later burst, letting loose thousands of new parasites that go on to infect more red blood cells. Mosquitoes get malaria…