Final answer:
Primary lesions refer to various types of skin abnormalities such as macules, patches, papules, plaques, nodules, tumors, vesicles, bullae, pustules, and abscesses, each with its unique characteristics and potential indications for different skin conditions.
Step-by-step explanation:
Primary lesions refer to different types of skin abnormalities that have distinct appearances and characteristics. Here are definitions for several types of primary lesions:
- Macule/macula: A flat, distinct, discolored area of skin less than 1 centimeter wide that does not involve any change in the thickness or texture of the skin.
- Patch (such as vitiligo): A large macule, greater than 1 centimeter wide.
- Papule: A small, raised, solid pimple or swelling on the skin that is usually less than 1 centimeter in diameter.
- Plaque: A raised, firm, and rough lesion with a flat top surface greater than 1 centimeter in diameter.
- Nodule: A growth of abnormal tissue or a lesion that resembles a cyst but with a less defined boundary, and that is deeper and firmer than a papule.
- Tumor: A solid, abnormal mass of tissue that can be benign or malignant. It is larger than a nodule.
- Vesicle: A small fluid-filled blister on the skin, less than 5 millimeters in diameter.
- Bulla: A large blister that is usually more than 5 millimeters in diameter.
- Pustule: A small, pus-producing (suppurative), fluid- or pus-filled bump on the skin.
- Abscess: A pus-filled lesion; any suppurative (pus-producing) infection of the skin, often resulting from bacterial infection.
Examples of these lesions include a large brown spot on the skin sprinkled with darker specks, which could be a macule or patch. Small lesions with an irregular border and parts that appear red, white, blue, or blue-black might suggest a more serious condition like melanoma, and a dark lesion on the palms, soles, fingertips, toes, or mucous membranes could be a concerning sign requiring medical evaluation.