Primary Skin Lesions Overview

Primary Skin Lesions

• Primary skin lesions appear on healthy skin, directly caused by the skin disease.
• Various forms, including macules, papules, nodules, plaques, wheals, vesicles, pustules, bullae, and cysts.

Macule

• A flat, discolored area of skin, with no visible change in thickness or texture.
• Size is less than 1 cm.
• Possible causes include hyperemia, dilated blood vessels, extravasation of red blood cells and changes in melanin production (e.g., freckles, vitiligo).

Papule

• A solid, raised area of skin
• Less than 1 cm in diameter
• Potential causes include epidermal thickening or cellular infiltration (e.g., skin tags, warts).

Nodule

• Solid, raised, and palpable lesion deeper than papule
• Size ranges from 0.5 cm to 5 cm
• Can be caused by various inflammations, growths or infections.

Plaque

• Elevated and solid area of skin, larger than 1 cm.
• May be flat or slightly raised. May be formed from many papules.

Wheal

• Elevated, transient skin lesion that is red or pale in color.
• Develops due to edema of the dermis
• Typically fades within 24 hours.

Vesicle

• Elevated skin lesion, filled with clear/serous fluid.
• Less than 1 cm in diameter

Pustule

• Vesicle containing purulent fluid (pus).

Bulla

• Fluid-filled lesion larger than 1 cm, often containing serous fluid.

Cyst

• A sac-like structure containing fluid or semisolid material.
• Enclosed within connective tissue.

This quiz covers the characteristics of primary skin lesions including macules, papules, nodules, plaques, and more. It highlights their appearances, sizes, and potential causes. Test your understanding of these important dermatological concepts.