Dermatology Terminologies Flashcards
What is a macule?
- 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.
What is a patch?
• A macule with a diameter greater than 2 cm is called a patch.
What is a papule?
• A papule is a circumscribed, raised lesion, of epidermal or dermal origin, 0.5-1.0 cm in diameter.
What is a nodule?
• A nodule is similar to a papule but greater than 1.0 cm in diameter.
What is a plaque?
• A plaque is a circumscribed, superficial, elevated plateau area 1.0-2.0 cm in diameter.
What are vesicles and bullae?
- 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.
What is a bulla?
•A bulla is a vesicle larger than 0.5 cm.
What is lichenification?
- This is a hard thickening of the skin with accentuated skin markings.
- It commonly results from chronic inflammation and rubbing of the skin.
What are discoid lesions?
Coin-shaped lesions.
What are pustules?
- Lesions containing purulent material- which may be due to infection
- Sterile pustules (inflammatory polymorphs) are seen in pustular psoriasis and pustular drug reactions.
What is atrophy?
- 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.
What is ulceration?
- This results from the loss of the whole thickness of the epidermis and upper dermis.
- Healing results in a scar.
What is excoriation?
• This is a partial or complete loss of epidermis as a result of scratching.
What is erosion?
• Superficial loss of epidermis that generally heals without scarring.
When a lesion is crusted, what does it mean?
• Dry serous fluid forming a crust (underlying epidermis or dermis is usually disrupted)
What is fissuring?
• Fissures are slits through the whole thickness of the skin.
What is desquamation?
• Peeling of the superficial scales, often following acute inflammation.
What are angular lesions?
Ring-shaped lesions.
What does reticulate mean?
- Reticulate means ‘net-like’
* Most commonly seen when the pattern of subcutaneous blood vessels become visible
What does violaceous mean?
• A purple discoloration, usually of the skin.
What is acral distribution?
• Acral distribution of skin lesions involves the distal aspects of the head (ears, nose) and the extremities (hands, fingers, feet, toes)
What is dermatoscopy distribution?
• 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.
What is intertriginous distribution?
• Intertriginous distribution involves skin creases and folds. An intertriginous pattern includes involvement of the axillae, crural fold, gluteal crease, and possibly the inframammary fold.
What is a lymphangitic pattern?
•A lymphangitic pattern of skin lesions or subcutaneous lesions appears along the path of the lymph channels of the leg or arm.
What is a photodistributed pattern?
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.
What is a widespread distribution?
- 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.
What is ecchymosis?
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.
What is petechiae?
Tiny 1-2 mm, initially purpuric, non-blanchable macules resulting from tiny haemorrhages.
What is palpable purpura?
Raised, palpable discoloration of skin or mucous membrane due to vascular inflammation in the skin and extravasation of blood.
Character of a purpuric rash?
Petechiae, ecchymosis, and palpable purpura do not blanch because blood has leaked outside the vessels into the surrounding skin.
What is Eschar?
A scab or dry crust that results from trauma, infection or excoriating skin disease.
What is a gangrene?
Gangrene is a usually black tissue due to obstruction, diminution or loss of blood supply.
Gangrene may be wet or dry.
What are eschar and gangrene?
Necrosis
