Terminology Flashcards
Macule
circumscribed, flat discolored lesion. <5cm in diameter
example: freckle
patch
a macule >1cm in diameter.
Flat with discolored
Papule
SOLID elevation of the skin less than 0.5cm in diameter.
Significance: infiltration of the skin with fluid, cells and or debris
Examples: pyoderma, miliary dermatitis.
Pustule
elevated lesion of the epidermis that is filled with leukocytes.
Significance: inflammation
Examples: pyoderma, autoimmune disease.
Lesions often develop from papules into pustules
Epidermal Collarette
circular ring of scale-crust representing the remains of a pustule, vesicle or bulla
Significance: remnant (footprint) of primary lesions
Examples : pyoderma (most common cause) , autoimmune disease, dermatophytosis
Wheal
edematous plaque (flat elevated lesion)
Significant: inflammation, vascular leakage. Type 1 hypersensitivity reaction
Example: urticaria
Plaque
flat elevated lesions of the skin. >0.5 cm in diameter
Significance: cutaneous infiltration of cells or fluid
Example: feline eosinophilic plaque
Vesicle
circumscribed lesion of free fluid <0.5 cm in diameter.
significance: damage to vasculaure or (BMZ). Small blister.
Bulla
circumscribed lesion of free fluid > 0.5cm in diameter - large blister.
Nodule
solid lesion of the skin >0.5 in diameter.
Significance: cellular infiltration of the skin. (big papule)
Examples: neoplasia, granulomatous inflammation
Tumor
solid elevated lesion >1.0cm in diameter “large mass”
May involve any structure in the skin and or subcutis.
Significance: cellular infiltration of the skin
Examples: neoplasia, inflammation
scale
accumulation of dead epidermal cells on the surface.
Significance: hyperkeratosis, changed epidermal kinetics, inability to slough cells
Examples: familial seborrhea, sebaceous adenitis.
Follicular Cast
a collection fo keratin and follicular debris adhering to a hair shaft above the follicular osteum
Significance- follicular hyperkeratosis or inflammation
Example- sebaceous adenitis.
- if you don’t force this out, as the hair grows, it can come out as the hair is extruded
Crust
accumulation of cells, serum and or blood on the skin. Lay term: Scab
Significance: inflammation, leakage through the epidermis (good information on histopathology)
Examples: autoimmune diseases, pyoderma
Erosion
Definition- focal loss of epidermis not extending into the dermis
Significance: physical damage to the skin
Example: secondary to scratching or rubbing (pruritus)
Excoriation
Definition: an erosion caused by scratching
Significance: moderate to severe damage
Example: pruritus resulting in visible “scratches”
Ulcer
Break in continuity of the epidermis
Significance
- severe damage to the epidermis
- indicates loss of protective functions of the epidermis
Example: infectious diseases (fungal), autoimmune diseases
Fistulous draining tracts
an ulcer (opening) in the epidermis Allows clearing/removal of foreign material from dermis/subcutis - foreign bodies - hair - parasites Most often reflect furunclosis
Furunculosis
deep infection of the hair follicle leading to abscess formation with accumulation of pus and necrotic tissue.
- body has an autoimmune response to the hair itself.
Lichenification
Definition- an area of thickened epidermis, with accentuated skin markings
Significance: represents area of chronic irritation/inflammation
Example: changes secondary to rubbing (periocular)
Comedo
Definition: a plug of keratinized and/or subaceous material in a hair follicle Lay term: blackhead
-when kneeding the skin for skin scrapings, follicular plugs can be seen
Significance: hyperkeratosis of the follicle, genetic influences
Example is the schnauzer comedo syndrome
Scar
definition: abnormal formation of connective tissue suggesting dermal damage
Significance: area of previous damage, often irreversible
Example cicatricial alopecia due to dermatomyositis
medical term for a scar
cicatrix
Atrophy
definition: thinning of the epidermis or dermis as a result of loss of normal structures
Significance: physical damage, nutrient damage, alterations in growth factors or control mechanisms
Examples: fragile skin syndrome in hyperadrenocorticism. topical Glucocorticoids can cause epidermal atrophy
