Final answer:
The difference between a macule and a patch is 'c) Size.' A macule is less than 1 centimeter, while a patch is larger than 1 centimeter.
Step-by-step explanation:
The difference between a macule and a patch is primarily related to their size. A macule is a flat, distinct, colored area of skin that is usually less than 1 centimeter in diameter, making it smaller in size, while a patch is similar except that it is larger than 1 centimeter. For instance, Figure 5.20 in the reference material describes melanomas as typically presenting as large brown or black patches, suggesting that these are larger than 1 centimeter and hence are referred to as patches rather than macules.
For clarity, other terms like lesions with irregular border or various color patterns, such as those mentioned for melanoma and measles, are describing either the configuration or the appearance but not the difference between a macule and a patch. Hence, with the information provided, the correct answer to the student’s question is 'c) Size.'