A raised blister-like area on the skin caused by an intradermal injection is called a:

A raised blister-like area on the skin caused by an intradermal injection is known as a wheal. This occurs due to the local accumulation of fluid and elevation of the skin in response to the injection, which is a common reaction for tests like the tuberculin skin test. Wheals are typically temporary and can vary in size, appearing as small, swollen areas that can often resolve within a few hours.

The other terms listed do not accurately describe this phenomenon. For instance, "deltoid" refers to the muscle region of the upper arm where intramuscular injections might be administered, rather than a characteristic of the skin. "Colloids" denote mixtures that do not settle out, often used in a medical context to refer to certain types of solutions or dressings, but they are not skin reactions. "Conjunctiva" refers to the membrane covering the eye and not related to skin reactions or responses to injections. Understanding these distinctions is vital in pharmacy practice, especially in relation to drug administration and the body's responses.