DR: Abnormal skin Flashcards
(124 cards)
1
Q
Define abrasion
A
superficial removal of the epidermis
2
Q
Define abscess
A
Localised collection of pus in a cavity formed by necrosis of tissue. Dermal or stratum corneum accumulation of pus
3
Q
Define acantholysis
A
Loss of cohesion between cells of living epidermis (especially stratum
spinosum: acanthus = thorn, spine)
4
Q
Define acanthocyte
A
Epidermal cell free in vesicle or pustule caused by acantholysis
5
Q
Define acanthosis
A
Hyperplasia of stratum spinosum
6
Q
Define acariasis
A
Infestation with any mites
7
Q
Define acral
A
Pertaining to the distal parts of the body
8
Q
Define actinic
A
Referring to the harmful effects of ultraviolet light
9
Q
Define adnexa
A
Cutaneous appendages (hair, claws and glands). Plural adnexae
10
Q
Define allergen
A
A substance capable of initiating an allergic response
11
Q
DEfine allergy
A
hypersensitivity reaction initiated by specific immunological
mechanisms
12
Q
Define alopecia
Histopathology
Example
A
Absence of hair in an area where it is normally present
HISTO: various, follicular atrophy or dystrophy if hairgrowth disrupted, may be inflammatory patterns if alopecia is traumatic
EXAMPLE = endocrine usually causes atrophic pattern. FAD cats often lead to traumatic alopecia
13
Q
Define anagen
A
Growth phase of hair cycle
14
Q
Define anaphylaxis
A
An exaggerated immune response to a foreign protein
15
Q
Define annular
A
ring-shaped
16
Q
Define anthropophilic
A
With a preference for man; dermatophytes
17
Q
Define atopy
A
Strictly ‘strange disease’. Popularly an inherited hypersensitivity state
mediated by reaginic antibody
18
Q
What is an auriscope
A
Synonym for ‘otoscope’
19
Q
Define bulla
Histopathology
Example
A
A large vesicle or blister (>1cm), contains clear fluid
HISTO: intra or subepidermal separation without marked cellular accumulation, often viral infection or autoimmune disease
EXAMPLE: FMDV, BP
20
Q
Define calcinosis
A
Accumulation of calcium crystals in the skin
21
Q
Define callus
A
Hypertrophy of the epidermis, especially over pressure points
22
Q
Define catagen
A
Transition phase of the hair cycle
23
Q
Define cellulitis
A
Used to described chronic, deep bacterial infection of the dermis and
subcutis with a diffuse, rapidly spreading, suppurative response
dissecting along and through tissue planes
24
Q
Define cerumen
A
The wax like secretions of the apocrine glands of the ear canal
25
Define comedo
Plugged (with keratinous debris) and dilated hair follicle, (pl. comedones). = blackheads. devoid of hair
HISTO = follicular keratinisation defects, +/- hair growth arrest
EXAMPLE dogs with Demodex. Also Cushings, Hypothyroidism, primary defects of keratinisation, idiopathic seborrhoea
26
Define cornification
The maturation process of epidermal cells (syn. keratinisation)
27
Define crust
Histopathology
Example
Solid accumulation of exudate on the skin surface. serocellular or haemorrhagic
HISTOPATHOLOGY: ulceration or exocytosis of inflammatory cells through epidermis, +/- spongiosis
EXAMPLE: canine scabies
28
Define cutis
The whole skin
29
Compare and contrast follicluitis with furunculosis
- FOLLICULITIS = inflammation of a follicle
- FURUNCULOSIS = inflammation and destruction of a follicle. E.g. perianal fistula and/or furunculosis in GSD. Deep pyoderma causing furunculosis.
30
Define demodicosis
A skin disease associated with infestation with Demodex mites
31
Define dermatitis
Inflammation of the skin
32
Define dermatome
Area of skin supplied with afferent nerve fibres by a single dorsal
spinal root also the lateral part of an embryonic somite. In surgery,
instrument for removing thin slices of skin for grafting.
33
Define dermatomycosis
Fungal disease of the skin (any fungus)
34
Define dermatophyte
A fungus parasite of skin, hairs or nails of the genera Microsporum,
Trichophyton or Epidermophyton
35
Define dermatosis
A pathological condition of the skin
36
Define dyskeratosis
Abnormal, premature or imperfect keratinisation of keratinocytes
37
Define dysplasia
Abnormality of development. Also alteration in size, shape and
organisation of adult cells
38
Define dystrophy
Wrong growth
39
Define ecchymosis
Dermal haemorrhage greater than 1 cm diameter
40
Define epidermal collarette
| Example
A peeling edge of epithelium surrounding an ulcer or erosion. (the footpad of a pustule, a secondary lesion. In dogs, most commonly caused by Staph). I.e. a circular lesion with a peripheral rim of scale. secondary lesion as evolves from pustule
EXAMPLE: canine pyoderma
41
Define epidermolysis
Degeneration of the epidermal basal layer resulting in separation of
the epidermis from the dermis
42
Define erosion
| Example
Superficial ulcer involving only epidermis and healing without scarring. The dermo-epidermal junction is intact. SECONDARY LESION. e.g. drug eruption
43
Define erythema
Reddening of the skin caused by congestion of the capillaries
44
Define excoriation
Histology
Example
linear trauma often with erosions and ulcers caused by self trauma
HISTOLOGY: if associated with pruritius, can expect various patterns of skin inflammation, especially perivascular dermatitis
EXAMPLE: feline FAD
45
Define exfoliation
The shedding of leaf-like scales or layers
46
Define fissure
Linear cleavage into epidermis or dermis caused by disease or injury
47
Define follicular cast
Histopathology
Example
An accumulation of keratin and follicular material that adheres/is compressed to the hair shaft extending above the follicular ostia.
HISTO: follicular keratinisation defect
EXAMPLE Demodecosis, idiopathic seborrhoea, endocrine disease
48
Define furunculosis
Rupture of hair follicles associated with severe inflammation
49
Define geophilic
Pertaining to organisms that normally inhabit the soil
50
Define glabrous
Strictly smooth, referring to hairless skin, popularly relatively hairless
51
Define granuloma
A circumscribed tissue reaction where the histiocyte is the
| predominant cell type
52
Define gynaecomastia
Enlargement of the male mammary gland
53
Define hyperhidrosis
Increases sweating
54
Define hyperkeratosis
An increased thickness of the stratum corneum (sacling, non-living layers).
55
Define hyperplasia
increase in stratum spinosum thickness (i.e. living layers) - stimulated by inflammatory cytokines, almost irrespective of cause.
56
Define hypersensitivity
Describes objectively reproducible symptoms or signs initiated by
exposure to a defined stimulus at a dose tolerated by normal persons
57
Define hypotrichosis
Less than the normal amount of hair
58
Define intertirginous
Rubbing against each other. Used to refer to areas in which the skin
layers opposed one against the other e.g. axilla
59
Define intertrigo
Frictional inflammation in poorly ventilated areas e.g. skin folds
60
Define keratinocyte
Epidermal cell undergoing maturation
61
Define keratolytic
Promoting loosening or separation of cells of the stratum corneum
62
Define keratoplastic
Promoting ordered keratinisation of stratum corneum. Term is also
used in a different sense in relation to plastic surgery of the cornea
63
Define keratosis
A condition of excessive development of horny tissue
64
Define kerion
A nodular, moist, circumscribed infection of the skin and hair follicles
with fungi or bacteria
65
Define lentigo
When describing a single lesion - a flat, spot due to increased melanin
deposition and an increased number of melanocytes. Plural is
“lentigenes”.
66
Define leukoderma
Lack of skin pigmentation
67
Define leukotrichia
Lack of hair pigmentation
68
Define lichenification
Histology
Example
A thickening of the superficial layers of the skin characterised by exaggerated crevices. Accentuation of normal skin markings leading to elephant skin appearance. SECONDARY LESION
HISTOLOGY: epidermal hyperplasia and superficial dermal inflammation
EXAMPLE: chronic, poorly controlled allergic diseases
69
Define macule
Histopathology
Example
Circumscribed change in skin colour less than 1 cm in diameter.
HISTO: erythema or pigment disturbance
EXAMPLE: loss of pigment in vitiligo
70
Define melanoderma
Inreased skin pigmentation
71
Define melanotrichia
Abnormal (increased) hair pigmentation
72
Define miliary
Resembling a millet seed
73
Define mycetoma
Localized deforming tumour with sinus tracts and 'grains' or 'granules'
of the aetiological agent. 2 distinct groups: actinomycetic mycetomas
associated with bacterial filaments of 1 um diameter or less, and
eumycotic mycetomas (eumycetoma) associated with septate, hyphae
of at least 2-4 um diameter. Diagnosis dependent upon demonstration
of the sinuses and granules. When granule is composed of a pure
population of non-filamentous bacteria, a diagnosis of bacterial
granuloma ('botryomycosis') should be made.
74
Define myxoedema
A localised mycotic or actinomycotic infection of skin characterised by
a nodular lesion with sinus tracts and granules in the exudate.
75
Define necrolysis
Necrosis of epidermal cells leading to separation or exfoliation of
tissue due to necrosis
76
Define nevus
A circumscribed developmental defect of the skin
77
Define nikolsky sign
Ability to dislodge normal looking epidermis by sliding digital
pressure The dermo-epidermal junction is taken out to be able to do this therefore it is a pathological finding.
78
Define nodule
Histopathology
Example
A circumscribed, solid elevation > 1 cm in diameter that usually extends into the deeper skin layers
HISTOPATHOLOGY: dense accumulation of neoplastic or inflammatory cells in dermis and/or pannniculus
EXAMPLE: MCT, mycobacterial skin infection
79
Define onychogryphosis
Deformed overgrowth of nails
80
Define onychomadesis
Complete shedding of nails
81
Define onychomycosis
Fungal nail infection
82
Define onychorrhexis
A breakage or brittleness of a nail
83
What is an otoscope?
Instrument for examining the ear
84
Define papule
Histopathology
Example
= Solid elevation of skin less than 1 cm diameter (nodule if >1 cm)
- HISTO: dense accumulation of inflammatory cells in superficial and/or deep dermis
- EXAMPLE: flea bite allery
85
Define parakeratosis
Abnormal cornification, keratinocytes retain nuclei
86
Define paronchia
Inflammation of the tissue fold around the nail bed
87
Define patch
Histopathology
Example
A macule more than 1 cm in diameter (a macule is a circumscribed change in skin colour less than 1cm in diameter)
HISTO: erythema or pigment disturbance
EXAMPLE: loss of pigment in vitiligo
88
Define pediculosis
Infestation with lice
89
Define petechia
Haemorrhage of less than 1 cm diameter
90
Define pigmentary incontinence
Release of melanin granules into the superficial dermis
91
Define plaque
Flat topped swelling more than 1 cm diameter
92
Define pruritus
Intense and persistent itchiness (note spelling)
93
Define pseudomycetoma
'Dermatophyte pseudomycetoma' is a confusing term used to describe
a form of dermatophytosis this is, amongst veterinary species,
primarily reported in Persian cats with M. canis as the aetiological
agent. 'Fungal granuloma caused by M. canis' or 'granulomatous
dermatitis and panniculitis caused by M. canis' fit more closely with
the accepted disease nomenclature than 'pseudomycetoma'.
94
Define pustule
A small circumscribed elevation of the epidermis filled with pus (c.f. abscess where pus accumulates in the dermis or the subcutaenous tissue).
HISTO: dense accumulation of neutrophils (or eosinophils) within epidermis or superficial dermis
EXAMPLE: canine pyoderma
95
Define scale
Histopathology
Example
An accumulation of fragments of stratum corneum
HISTOPATHOLOGY: hyperkeratosis, induced by wide arrange of processes
EXAMPLE: idiopathic seborrhoea
96
Define scar
An area of fibrous tissue that has replaced the damaged dermis or subcutaneous tissue
97
Define spongiosis
Intercellular oedema in the epidermis
98
Define telogen
The resting phase of the hair cycle
99
Define ulcer
| Example
A break in the continuity of the epidermis with exposure of the underlying dermis but with intact basement membrane. e.g. BP
100
Define vesicle
Histopathology
Example
A blister less than 1 cm diameter, contains clear fluid, a circumscribed elevation of the skin
HISTO: intra or subepidermal separation without marked cellular accumulation, often viral infection or autoimmune disease
EXAMPLE: FMDV, BP
101
Define vitiligo
Depigmentation in focal areas where melanocytes are absent
102
Define wheal
A sharply demarcated raised lesion caused by dermal oedema. A more extensive wheal is known as angioedema (affects whole body region)
103
Define zoophilic
Pertaining to organisms adapted to animals
104
List different ways skin can react
```
Change of colour
Rash
Change of thickness
Abnormal material on surface
Hair loss
Defect in integrity
Lump or swelling
```
105
What are common Ddx for erythematous circles 3 (i.e. points of inflammation expanding outwards)
Staphylococcal erythema
Flea bite hypersensitivity
Fly bites
106
Ddx - skin change of colour to black 3
- Post-inflammatory/ chronic inflammation - esp. allergic dx & Malassezia dermatitis
- Tanning
- Hormonal
107
Causes - skin change of colour from black to grey
Loss of melanin from epidermis into dermis. Certain dx with focus on epidermis
108
Causes - skin change of black to white/ pink
Loss of melanocytes (insult or idiopathic)
109
What should you decide if you see red skin?
erythema or rash
110
Define rash
collection of skin lesions - diffuse or confluent (e.g. erythema, papules, pustules, crusted papules/ pustules, colarettes)
111
Ddx - papules
```
Staphylococcal pyoderma
Flea bite hypersensitivity
Scabies
Atopic dermatitis
Fly-bite hypersensitivity
Contact dermatitis
```
112
Example of crusted papule
miliary dermatitis
113
Ddx - pustules
* Staphylococcal pyoderma*
- Demodecosis
- Pemphigus
- Other rare sterile pustular disorders
114
What is an epidermal collarette the remnant of?
a papule or pustule in Staph pyoderma
115
What might be seen with epidermal collarettes?
Circular scaling
+/- central alopecia
+/- peripheral erythema
+/- central hyperpigmentation
116
What is increased epidermal thickness?
lichenification
117
What is increased dermal thickness?
infiltration with cells or mucin
118
What is decreased skin thickness caused by? Tx?
Due to atrophy. Tx is steroids.
119
What abnormal material might be present on the skin surface?
- excessive scale - surface scaling or follicular cast
- exudate - crust
- sweat, lipid
120
What are the patterns of alopecia?
- diffuse/partial/total
- focal/regional
- multifocal
- symmetrical
121
Causes of circular hair loss - 3
- staph folliculitis
- demodex
- dermatophytes
122
Name 5 defects in skin integrity
```
Fissure
Excoriation
Erosion
Ulcer
Draining tracts
```
123
Causes of erosions/ ulcers
```
self-trauma
Physical/chemical insult
Infection
Auto-immune dx
• primary, or secondary to vesicles/bullae
vasculopathy
tumour
```
124
What may cause draining tracts?
Process in/under skin ‘trying to get out’
| Infection, foreign body, necrosis
