Introduction to Dermatology (Basics of Dermatology)

Identify macules as flat, discolored skin areas under 1 cm and patches as discolorations over 1 cm, both without thickness changes; note vitiligo patches and psoriasis-related lesions over 1 cm.

Identify nodules as palpable solid lesions over 10 millimeters in dermis or subcutaneous tissue, and distinguish vertical epidermal elevations under five millimeters from vesicles and bullae by size and fluid.

Identify pustules and crusts, noting pus-filled lesions on the back, chest, or face, such as acne or smallpox, with dried exudate of serum, blood, or pus.

Identify scale as accumulation of the superficial epidermal layer, white or gray in color; differentiate erosion as superficial epidermal loss with an intact basement membrane, usually healing without scarring.

Ulcers involve epidermis loss with basement membrane and dermis exposure, unlike erosions that preserve the dermis; ulcers heal slowly and may get infected, while scars form fibrous tissue.

Explore skin atrophy, degeneration and thinning of the epidermis and dermis, linked to aging and corticosteroid use, and recognize a cyst as benign, round, encapsulated lesion containing fluid.

Lichenification arises from constant scratching, thickening the skin into a leathery, bark-like texture. A wheal is a superficial pale swelling with surrounding redness, lasting minutes to 24 hours and itching.

Learn how dermatoscopy uses a handheld instrument to examine skin lesions, visualize subsurface structures at the dermal-epidermal junction and upper dermis, and distinguish benign from malignant lesions, especially melanoma.

Practice self-assessment with dermatology MCQs that identify lesions from pictures, such as patches of discoloration, reddened allergic reactions, pustules, erosions, vesicles, crusts, and scales.