Primary lesions with examples

Question 1

What are primary skin lesions?

Answer 1

They develope from originally normal skin and are directly associated with a disease process.

Question 2

Which are the primary lesions?

Answer 2

• Macule/patche
• Papule
• Plaque
• Nodule
• Wheal
• Vesicle
• Pustule
• Cyst

Question 3

What are macules? Patches?

Examples?

Answer 3

Circumbscribed skin with altered color, without any elevation or depression.

A macular rash is called macular exanthema.

A patch is a macule > 1cm in diameter.

Examples of macules:

Vitiligo (white macules)

“Café au lait spots” (brown macules)

Mongolian spots (blue macules)

Port wine staines (red macules)

Question 4

What is a papule?

Examples?

Answer 4

Superficial, solid, raised lesions usually < 1cm in diameter with well or ill-defined borders. It is infiltrative.

A papular rash is called papular exanthema.

Examples:

• Solitary papules:
  
  • Dermal nevus, basal cell carcinoma, nodular melanoma
• Multiple papules:
  
  • ​Condyloma acuminata, lichen planus, syringomas, psoriasis, secondary syphilis, neurofibromatosis, …

Question 5

What is a plaque?

Examples?

Answer 5

Flat-topped, plateau-like solid elevation (papule) > 1cm with infiltration.

Examples:

• Solitary plaques:
  
  • Lichen simplex chronicus, Bowen’s disease, superficial spreading melanoma, …
• Multiple plaques:
  
  • Psoriasis, mycosis fungoides
• Lichenification:
  
  • ​Atopic dermatitis, eczematous dermatitis, psoriasis, mycosis fungoides, …

Question 6

What is a nodule?

Examples?

Answer 6

It is solid, round or oval, non-flat-topped elevation (papule) which is > 2cm in diameter. Arises from the dermis or subcutis.

​Examples:

• Solitary nodules:
  
  • Dermal nevus, basal cell carcinoma, nodular melanoma, …
• Mutliple nodules:
  
  • ​Lipoma, metastatic melanoma, metastatic cancer

Question 7

What is a wheal?

Examples?

Answer 7

Erythematous plaque of dermal origin. Edema under the surface. Characteristic of uritcaria.

Disappears within 24-48h.

A rash consisting of wheals is called urticarial exanthema or urticaria.

Question 8

What is a vesicle? Bulla?

Examples?

Answer 8

Circumbscribed epidermal or dermal clear fluid-filled raised lesion (blister) < 0.5cm in diameter. If > 0.5cm it is a bulla.

Examples of vesicular/bullous lesions:

Herpes simplex

Herpes zoster

Varicella bullous pemphigoid

Heat trauma

Question 9

What is a pustule?

Examples?

Answer 9

It is a raised vesicle filled with pus, which may be white, yellow, green or hemorrhagic.

Examples:

Folliculitis barbae

Impetigo

Pustular psoriasis

Smallpox

Herpes simplex and zoster

Question 10

What is a cyst?

Examples?

Answer 10

Cavity (closed sac) in the skin containing air, serous, pustular or haemorrhagic fluid, or semi-solid material (such as sebum). It’s covered by an epithelial wall.

Examples:

Epidermal cyst

Eccrine hydrocystoma

Cystic basal cell carcinoma