Reactions can range from mild redness to more severe blistering or swelling at the test site. These reactions are classified into: - Negative: No reaction. - Irritant Reaction: Redness without swelling. - Weak Positive Reaction: Mild redness and swelling. - Strong Positive Reaction: Intense redness, swelling, and possible blistering. - Extreme Positive Reaction: Severe blistering and ulceration.
