This document defines and provides examples of various skin lesions and rashes. It describes macules as flat, circumscribed areas less than 1 cm in diameter that are changes in skin color, such as freckles or measles. Papules are elevated and firm areas also less than 1 cm in diameter, exemplified by warts or moles. Nodules are deeper elevated lesions between 1-2 cm in diameter like erythema nodosum. Plaques are elevated, rough lesions greater than 1 cm across found in conditions like psoriasis.

1. Macule: flat circumscribed area that is a change in the
color of skin, less than 1 cm in diameter
Example: freckles, flat moles, petechiae, measles, scarlet
fever

2. • Papule: an elevated, firm, circumscribed area; less
than 1 cm in diameter
• Examples: wart, elevated moles, lichen planus

3. • Wheal: elevated, irregular-shaped area of cutaneous
edema; solid, transient, variable diameter
• Examples: insect bites, urticaria, allergic reaction

4. • Nodule: elevated, firm circumscribed lesion; deeper
in dermis than a papule; 1-2 cm in diameter
• Examples: erythema nodosum, lipoma

5. • Pustule: elevated, superficial lesion; similar to a
vesicle but filled with purulent fluid
• Examples: impetigo, acne

6. • Telangiectasia: fine, irregular, red lines produced by
capillary dilation
• Examples: telangiectasia in rosacea

7. • Scale: heaped-up, keratinized cells; flaky skin;
irregular; thick or thin; dry or oily; variation in size
• Example: flaking of skin with seborrhic dermatitis
following scarlet fever or flaking of skin following a
drug reaction; dry skin

8. • Scar: thin to thick fibrous tissue that replaces
normal skin following injury or laceration to the
dermis
• Example: healed wound or surgical incision

9. • Fissure: linear crack or break from the epidermis
to the dermis; may be moist or dry
• Examples: Athlete’s foot, cracks at the corner of
the mouth

10. • Erosion: Loss of part of the epidermis; depressed,
moist, glistening; follows rupture of a vesicle or
bulla
• Examples: varicella, variola after rupture

11. • Keloid: irregular-shaped, elevated, progressively
enlarging scar; grows beyond the boundaries of the
wound; caused by excessive collagen formation
during healing
• Examples: keloid formation following surgery

12. • Bulla: vesicle greater than 1 cm in diameter
• Examples: blister, pemphigus vulgaris

13. • Vesicle: elevated, circumscribed, superficial, not
into dermis, filled with serous fluid; less than 1
cm in diameter
• Examples: varicella (chickenpox), herpes zoster
(shingles)

14. • Cyst: elevated, circumscribed, encapsulated
lesion,; in dermis or subcutaneous layer; filled
with liquid or semisolid material
• Examples: sabaceous cyst, cystic acne

15. • Plaque: elevated, firm, and rough lesion with flat
top surface greater than 1 cm in diameter
• Examples: psoriasis, seborrheic, and actinic
keratoses

16. • Crust: dried serum, blood, or purulent exudates;
slightly elevated; size varies; brown, red, black, tan,
or straw-colored
• Examples: scab or abrasion, eczema

17. • Lichenification: rough, thickened epidermis
secondary to persistent rubbing, itching or skin
irritation; often involves flexor surface or
extremity
• Examples: chronic dermatitis

18. • Ulcer: loss of epidermis and dermis; concave;
varies in size
• Examples: decubiti, statis ulcer

19. • Tumor: elevated and solid lesion; may or may not
be clearly demarcated; deeper in dermis; greater
than 2 cm in diameter
• Examples: neoplasms, benign tumor. lipoma

20. • Excoriation: loss of the epidermis; linear
hollowed-out, crusted area
• Examples: abrasion or scratch, scabies

21. • Atrophy: thinning of skin surface and loss of skin
markings; skin translucent and paper-like
• Examples: striae; aged skin

22. • Patch: a flat, nonpalpable, irregular-shaped macule
greater than 1 cm in diameter
• Examples: vitiligo, port-wine stains, Mongolian
spots, cafe au lait patch