And for my money, the best show in TV's greatest decade was Lost in Space. It's impossible to describe what watching this show was like in the 1960s. It's an experience that simply can't be re-produced today.
The reaction reaches its peak about 48 to 72 hours after the PPD is injected. Waiting too long or not long enough may cause an underestimation of the reaction and, therefore, affect how the test is read.A positive test will cause redness, itching and a raised, hardened area of skin called an induration.
PPD skin test. The PPD skin test is a method used to diagnose silent (latent) tuberculosis (TB) infection. PPD stands for purified protein derivative. You will need 2 visits to your doctor's office for this test. At the first visit, the health care provider will clean an area of your skin, usually the inside of your forearm. You will get a small shot (injection) that contains PPD. The needle is gently placed under the top layer of skin, causing a bump (welt) to form. This bump usually goes away in a few hours as the material is absorbed. After 48 to 72 hours, you must return to your provider's office.