Dermatology Terminologies

Question 1

What is a macule?

Answer 1

• Macule is used to describe changes in colour without any elevation above the surface of the surrounding skin.
• There may be an increase in pigments such as melanin, giving a black or brown colour.
• Loss of melanin leads to a white macule.
• Vascular dilatation and inflammation produce erythema.

Question 2

What is a patch?

Answer 2

• A macule with a diameter greater than 2 cm is called a patch.

Question 3

What is a papule?

Answer 3

• A papule is a circumscribed, raised lesion, of epidermal or dermal origin, 0.5-1.0 cm in diameter.

Question 4

What is a nodule?

Answer 4

• A nodule is similar to a papule but greater than 1.0 cm in diameter.

Question 5

What is a plaque?

Answer 5

• A plaque is a circumscribed, superficial, elevated plateau area 1.0-2.0 cm in diameter.

Question 6

What are vesicles and bullae?

Answer 6

• They are raised lesions that contain clear fluid (blisters)
• They may be superficial within the epidermis or situated in the dermis below it.
• The more superficial the vesicles/bullae, the more likely they are to break open.

Question 7

What is a bulla?

Answer 7

•A bulla is a vesicle larger than 0.5 cm.

Question 8

What is lichenification?

Answer 8

• This is a hard thickening of the skin with accentuated skin markings.
• It commonly results from chronic inflammation and rubbing of the skin.

Question 9

What are discoid lesions?

Answer 9

Coin-shaped lesions.

Question 10

What are pustules?

Answer 10

• Lesions containing purulent material- which may be due to infection
• Sterile pustules (inflammatory polymorphs) are seen in pustular psoriasis and pustular drug reactions.

Question 11

What is atrophy?

Answer 11

• Atrophy refers to loss of tissue, which may affect the epidermis, dermis or subcutaneous fat.
• Thinning of the epidermis is characterised by loss of normal skin markings; there may be fine wrinkles, loss of pigment and a translucent appearance.
• In addition, sclerosis of the underlying connective tissue, telangiectasia or evidence of diminished blood supply may be present.

Question 12

What is ulceration?

Answer 12

• This results from the loss of the whole thickness of the epidermis and upper dermis.
• Healing results in a scar.

Question 13

What is excoriation?

Answer 13

• This is a partial or complete loss of epidermis as a result of scratching.

Question 14

What is erosion?

Answer 14

• Superficial loss of epidermis that generally heals without scarring.

Question 15

When a lesion is crusted, what does it mean?

Answer 15

• Dry serous fluid forming a crust (underlying epidermis or dermis is usually disrupted)

Question 16

What is fissuring?

Answer 16

• Fissures are slits through the whole thickness of the skin.

Question 17

What is desquamation?

Answer 17

• Peeling of the superficial scales, often following acute inflammation.

Question 18

What are angular lesions?

Answer 18

Ring-shaped lesions.

Question 19

What does reticulate mean?

Answer 19

• Reticulate means ‘net-like’

* Most commonly seen when the pattern of subcutaneous blood vessels become visible

Question 20

What does violaceous mean?

Answer 20

• A purple discoloration, usually of the skin.

Question 21

What is acral distribution?

Answer 21

• Acral distribution of skin lesions involves the distal aspects of the head (ears, nose) and the extremities (hands, fingers, feet, toes)

Question 22

What is dermatoscopy distribution?

Answer 22

• Dermatomal distribution involves an area of skin supplied with sensory innervation by a particular nerve root. Dermatomal distributions do not cross the midline of the body.

Question 23

What is intertriginous distribution?

Answer 23

• Intertriginous distribution involves skin creases and folds. An intertriginous pattern includes involvement of the axillae, crural fold, gluteal crease, and possibly the inframammary fold.

Question 24

What is a lymphangitic pattern?

Answer 24

•A lymphangitic pattern of skin lesions or subcutaneous lesions appears along the path of the lymph channels of the leg or arm.

Question 25

What is a photodistributed pattern?

Answer 25

A photodistributed pattern follows the sun-exposed skin.

Typical areas of involvement are the forehead, upper ears, nose, cheeks, upper lip, neck, forearms, and dorsum of the hands.

Question 26

What is a widespread distribution?

Answer 26

• A widespread distribution involves the entire - or almost the entire - body.
• Skin lesions occurring across many body locations can appear to be distributed randomly or haphazardly.
• Skin lesions found symmetrically on the extremities can be indicative of diagnoses of many aetiologies, including infectious, metabolic, genetic, and inflammatory causes.

Question 27

What is ecchymosis?

Answer 27

Extravasation of blood into the skin or mucous membranes.

Area of flat colour change may progress over time from blue-black to brown-yellow or green.

Question 28

What is petechiae?

Answer 28

Tiny 1-2 mm, initially purpuric, non-blanchable macules resulting from tiny haemorrhages.

Question 29

What is palpable purpura?

Answer 29

Raised, palpable discoloration of skin or mucous membrane due to vascular inflammation in the skin and extravasation of blood.

Question 30

Character of a purpuric rash?

Answer 30

Petechiae, ecchymosis, and palpable purpura do not blanch because blood has leaked outside the vessels into the surrounding skin.

Question 31

What is Eschar?

Answer 31

A scab or dry crust that results from trauma, infection or excoriating skin disease.

Question 32

What is a gangrene?

Answer 32

Gangrene is a usually black tissue due to obstruction, diminution or loss of blood supply.

Gangrene may be wet or dry.

Question 33

What are eschar and gangrene?

Answer 33

Necrosis