Primary Lesions

Macule:

• Circumscirbed, Flat (without elevation or depression), Nonpalpable change in skin color.
•  <1 cm in diameter.
• e.g., freckle, petechiae

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Patch:

• Similar to macule but > 1 cm

 

Papule:

• Palpable, circumscribed, solid elevation,
• Less than 1 cm in diameter
• e.g., elevated nevus

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Wheal:

• Irregularly shaped
• Elevated area or superficial localized edema
• varies in size
• Edematous papule
• e.g., hive, mosquito bite

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Nodule:

• Elevated solid mass
• Deeper and firmer than papule
• 1-2 cm
• e.g., wart

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Tumor:

• Solid mass that extends deep through subcutaneous tissue
• similar to Nodule
• larger than 2 cm
• e.g., epithelioma

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Plaque:

• an elevation above the skin with a plateau-like surface.

 

Vesicle:

• Circumscribed elevation of skin
• filled with serous fluid
• less than 1cm.
• e.g., herpes simplex, chickenpox

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Bulla:

• Similar to vesicle but > 1 cm.

 

Pustule:

• Circumscribed elevation of skin
• Similar to vesicle but filled with neutrophils and dead bacteria.
  • Fluid is white or yellow (pus)
• Varies in size
• e.g., acne, staphylococcal infection

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Secondary Lesions

Scale:

• an excess of horny material on the skin

Crust:

• scab consisting of dried blood, serum, or pus

Erosion:

• Scooped out and shallow break.  No damage to the dermis

Fissure:

• linear form of an erosion

Ulcer:

• Deep lesion involving the dermis

Eschar:

• Dark colored, hard to remove crust on ulcer

 

Shapes and Arrangements of Lesions

Annular:

• round lesion, ring-like.
• The rim is different from the center

Linear:

• long, thin lesion or smaller lesions in a long, thin line.

Target or Iris:

• Concentric rings like an arches target.

Imbricated:

• Target lesions with near form of an erosion

Serpiginous:

• Snake-like.
• Partially circular and undulating

Geographic:

• Outline of a continent on a map

Vegetating:

• Lesion has a surface that grows outward in uneven, fleshy tufts that feel soft.

Verrucous:

• Wart-Like
• Tufts of protruding lesion are hyperkeratotic, not soft.

Zosteriform:

• Conforming to the distribution of a nerve root.

Polycyclic or Circinate:

• Annular lesions grow together, Parts of their cirlces form larger lesion.

Grouped:

• Several similar lesions located in close proximity surrounded by a large area of normal skin

 

Morphology of Lesions

The following aspects should be included in every description:

1. Size
2. Color
3. Consistency: Soft, Medium, Firm
4. Configuration: Shape or outline of lesion
5. Margination: sharp or diffuse
6. Surface Characteristics: Smooth or rough