Dermatology Flashcards
(105 cards)
1
Q
Define pruritus
A
Itching
2
Q
Define lesion
A
Area of altered skin
3
Q
Define naevus
A
Localised malformation of tissue structure (mole)
4
Q
Define comedone
A
Plug in sebaecous follicle containing altered sebum, bacteria and cellular debris
Can present as either open (blackhead) or closed (whitehead)
5
Q
Define flexural
A
In body fold
6
Q
Define Koebner phenomenon
A
Linear eruption arising at site of trauma
7
Q
Define discrete
A
Individual lesions separated from each other
8
Q
Define confluent
A
Lesions merging together
9
Q
Define annular
A
Circle or ring
10
Q
Define discoid/nummular
A
Coin shaped/round lesion
11
Q
Define erythema
A
Redness which blanches on pressure
12
Q
Define purpura
A
Red or purple colour which does not blanch on pressure
- petechiae = small pinpoint macules
- ecchymoses = larger bruise like patches
13
Q
Define hypopigmentation
A
Areas of paler skin
14
Q
Define depigmentation
A
White skin due to absence of melanin
15
Q
Define hyperpigmentation
A
Darker skin
16
Q
Define macule
A
Flat area of altered colour
17
Q
Define patch
A
Larger flat area of altered colour or texture
18
Q
Define papule
A
Solid raised lesion < 0.5cm in diameter
19
Q
Define nodule
A
Solid raised lesion > 0.5cm in diameter with a deeper component
20
Q
Define plaque
A
Palpable scaling raised lesion > 0.5cm in diameter
21
Q
Define vesicle
A
Raised clear fluid-filled lesion < 0.5cm in diameter
Small blister
22
Q
Define bulla
A
Raised clear fluid-filled lesion > 0.5cm in diameter
Large blister
23
Q
Define pustule
A
Pus-containing lesion < 0.5cm in diameter
24
Q
Define abscess
A
Localised accumulation of pus in the dermis or subcutaneous tissues
25
Define wheal
Transient raised lesion due to dermal oedema
26
Define boil
Staphylococcal infection around or within hair follicle
27
Define carbuncle
Staphylococcal infection of adjacent hair follicles
| Multiple boils
28
Define excoriation
Loss of epidermis following trauma
29
Define lichenification
Well-defined roughening of skin with accentuation of skin markings
30
Define scales
Flakes of stratum corneum
31
Define crust
Rough surface consisting of dried serum, blood, bacteria and cellular debris that has exuded through eroded epidermis
32
Define scar
New fibrous tissue which occurs post-wound healing a- - atrophic = thinning
- hypertrophic = hyperproliferation within wound boundary
- keloidal = hyperproliferation beyond wound boundary
33
Define ulcer
Loss of epidermis and dermis
34
Define fissue
Epidermal crack often due to excess dryness
35
Define striae
Linear areas which progress from purple to pink to white
| - histopathological appearance of a scar
36
What are striae a/w?
Excessive steroid usage
Glucocorticoid production
Growth spurts
Pregnancy
37
Define alopecia
Loss of hair
38
Define hirsutism
Androgen-dependent hair growth in a female
39
Define hypertrichosis
Non-androgen dependent pattern of excessive hair growth
40
Define clubbing
Loss of angle between posterior nail fold and nail plate
41
What is clubbing associated with?
Suppurative lung disease
Cyanotic heart disease
Inflammatory bowel disease
Idiopathic
42
Define koilonychia
Spoon-shaped depression of nail plate
43
What is koilonychia a/w?
Iron-deficiency anaemia
Congenital
Idiopathic
44
Define onycholysis
Seperation of distal end of nail plate from nail bed
45
What is onycholysis a/w?
Trauma
Psoriasis
Fungal nail infection
Hyperthyroidism
46
Define pitting
Punctate depression of nail plate
47
What is nail pitting a/w?
Psoriasis
Eczema
Alopecia areata
48
Define cellulitis
Spreading bacterial infection of skin
| - involves deep subcutaneous tissue
49
Define erysipelas
Acute superficial form of cellulitis
| - involves dermis and upper subcutaneous tissue
50
Causes of cellulitis
Streptococcus pyogenes
| Staphylococcus aureus
51
Risk factors for cellulitis
```
Immunosuppression
Wounds
Leg ulcers
Toeweb intertrigo
Minor skin injury
```
52
Presentation of cellulitis
```
Most common in lower limbs
Local signs of inflammation
- tumor
- rubor
- calor
- dolor
Systemically unwell with fever, malaise or rigors
```
53
Management of cellulitis
Antibiotics - flucloxacillin or benzylpenicillin
| Supportive care - rest, leg elevation, sterile dressings and analgessia
54
Complications of cellulitis
Local necrosis
Abscess
Septicaemia
55
Define staphylococcal scaled skin syndrome
Serious skin infection caused by staphylococcus aureus
| Red blistering skin - looks like burn/scald
56
Causes of SSSS
Production of circulating epidermolytic toxin from phage group II, benzylpenicillin resistant (coagulase positive) staphylococci
57
Presentation of SSSS
Commonly seen in infancy and early childhood
Develops within few hours to few days
Worse over face, neck, axillae and groins
Scald-like appearance followed by large flaccid bulla
Perioral crusting
Intraepidermal blistering
Painful
58
Management of SSSS
Antibiotics - erythromycin
| Analgesia
59
Cause of superficial fungal infections
Dermatophytes - tinea/ringworm
Yeasts - candidiasis, malassezia
Moulds - aspergillus
60
Define tinea corporis
Tinea infection of trunk and limbs
| Itchy, circular or annular lesions with clearly define, raised and scaly edge
61
Define tinea cruris
Tinea infection of the groin and natal cleft
62
Define tinea pedis
Athlete's foot
| Moist scaling and fissuring in toewebs, spreading to sole and dorsal aspect of foot
63
Define tinea capitis
Scalp ringworm
| Patches of broken hair, scaling and inflammation
64
Define candidiasis
Candidial skin infection
| White plaques on mucosal areas, erythema with satellite lesions in flexures
65
Treatment of superficial fungal infections
Establish correct diagnosis - skin scrapings, hair or nail clippings or skin swabs
Treat know precipitating factors
Topical antifungal agents - terbinafine cream
Oral antifungal for severe - itraconazole
Avoid topical steriods
66
Describe squamous cell carcinoma
Locally invasive malignant tumour of epidermal keratinocytes or appendages
Potential to metastasise
67
Risk factors of squamous cell carcinoma
Excessive UV exposure
Pre-malignant skin conditions - actinic keratoses
Chronic inflammation - leg ulcers, wound scars
Immunosuppression
Genetic
68
Presentation of squamous cell carcinoma
Keratotic (scaly, crusty), ill-defined nodule which may ulcerate
69
Management of squamous cell carcinoma
Surgical excision
Mohs micrographic surgery - ill-defined, large, recurrent
Radiotherapy - large, non-resectable tumours
70
Describe malignant melanoma
Invasive tumour of epidermal melanocytes
| Potential to metastasise
71
Risk factors for malignant melanoma
Excessive UV exposure - always burns never tans
History of multiple moles or atypical moles
FH
PH
72
Presentation of malignant melanoma
```
Asymmetrical shape
Border irregularity
Colour irregularity
Diameter > 6mm
Evolution of lesion
Symptoms - bleeding, itching
More common on legs in women and trunk in men
```
73
Types of malignant melanoma
Superficial spreading
- common on lower limbs, in young and middle age
- related to intermittent high-intensity UV exposure
Nodular melanoma
- common on trunk, in young and middle aged adults
- related to intermittent high-intensity UV exposure
Lentigo maligna melanoma
- common on face, in elderly population
- related to long-term cumulative UV exposure
Acral lentiginous melanoma
- common on palms, coles and nail beds, elderly population
- no clear relation to UV exposure
74
Management of malignant melanoma
Surgical excision - definitive treatment
Radiotherapy
Chemotherapy - metastatic disease
75
Functions of normal skin
```
Protective barrier against the environment
Temperature regulation
Sensation
Vitamin D synthesis
Immunosurveillance
Appearance/cosmesis
```
76
Function of main cell types in the epidermis
Keratinocytes - produce keratin as a protective barrier
Langerhan's cells - present antigens and activate T-lymphocytes for immune protection
Melanocytes - produce melanin - gives pigment to skin and protects cell nuclei from UV radiation induced DNA damage
Merkel cells - contain specialised nerve endings for sensation
77
Layes of the epidermis
Stratum basale - actively dividing cells - deepest layer
Stratum spinosum - differentiating cells
Stratum granulosum - cells lose nuclei and contain granules of keratohyaline - secrete lipids into intracellular spaces
Stratum corneum - layer of keratin - most superficial
78
Types of sweat glands
Eccrine - universally distributed
Apocrine - found in axillae, areolae, genitalia and anus
- function only from puberty onwards
79
Stages of wound healing
Haemostatsis
- vasocontriction and platelet aggregation
- clot formation
Inflammation
- vasodilation
- migration of neutrophils and macrophages
- phagocytosis of cellular debris and invading bacteria
Proliferation
- granulation tissue formation and angiogenesis
- re-epilelialisation
Remodelling
- collagen fibre re-organisation
- scar maturation
80
Define atopic eczema
Characterised by papules and vesicles on an erythematous base
Atopic eczema - most common
- usually develops by early childhood and resolves during teenage years
81
Causes of atopic eczema
Not fully understood
Commonly positive FH of atopy
Primary genetic defect in skin barrier function
82
Exacerbating factors of atopic eczema
```
Infections
Allergens - chemicals, food, dust, pet fur
Sweating
Heat
Severe stress
```
83
Presentation of atopic eczema
Commonly presents as itchy, erythematous dry scaly patches
More common on face and extensor aspects of limbs in infants and flexor aspects in children and adults
Acute lesions are erythematous, vestibular and weepy
Chronic scratching/rubbing can lead to excoriations and lichenification
84
Management of atopic eczema
General measures
- avoid exacerbating agens
- frequent emollients/bandages/bath oil or soap substitute
Topical therapies
- topical steriods for use in flare-ups
- topical immunomodulators as steriod sparing
Oral therapies
- antihistamines for symptomatic relief
- antibiotics for secondary bacterial infections
- antivirals for secondary herpes infections
Phototherapy and immunosuppressants for severe non-responsive cases
85
Complications of atopic eczema
Secondary bacterial infection - crusted weepy lesion
| Secondary viral infection - pearly papules with central umbilications, viral warts
86
Define acne vulgaris
Inflammatory disease of the pilosebaceous follicle
87
Causes of acne vulgaris
Hormonal - androgen
88
Contributing factors of acne vulgaris
Increased sebum production
Abnormal follicular keratinization
Bacterial colonisation
Inflammation
89
Presentation of acne vulgaris
Mild acne - non-inflammatory lesions
- open and closed comedones (black and whiteheads)
Moderate and severe acne - inflammatory lesions
- papules, pustules, nodules and cysts
Commonly affects face, chest and upper back
90
Management of acne vulgaris
```
General measures
- no specific food identified
- treatment needs to be continues for at least 6 weeks to produce effect
Topical therapies
- benzoyl peroxide
- topical antibiotics
- topical retinoids
Oral therapies
- antibiotics
- anti-androgens (female)
Oral retinoids
```
91
Complications of acne vulgaris
Post-inflammatory hyperpigmentation
Scarring
Deformity
Psychological and social effects
92
Define psoriasis
Chronic inflammatory skin disease due to hyperproliferation of keratinocytes and inflammatory cell infiltration
93
Types of psoriasis
```
Chronic plaque - most common
Guttate - raindrop lesions
Seborrhoeic - naso-labial and retro-auricular
Flexural - body folds
Pustular - palmar-plantar
ERythrodermic - total body redness
```
94
Causes of psoriasis
Complex interaction between genetic, immunological and enviromental factors
95
Precipitating causes of psoriasis
```
Trauma
Infection - tonsillitis
Drugs
Stress
Alcohol
```
96
Presentation of psoriasis
Well-demarcated erythematous scaly plaques
Lesions can be itchy, burning or painful
Common on extensor surfaces of body and over scalp
Auspitz sign - scratch and gentle removal of scales causes capillary bleeding
50% -> nail changes - pitting, onycholysis
5-8% -> psoriatic arthropathy
97
Management of psoriasis
```
General measures
- avoid known precipitating factors
- emolients to reduce scales
Topical therapies
- vitamin D analogues
- corticosteriods
- coal tar preparations
- dithranol
- retinoids
- keratolytics
- scalp preparations
Phototherapy
Oral
- methotrexate
- retinoids
- ciclosporin
- mycophenolate mofetil
- fumaris acid esters
- biological agents - infliximab
```
98
Complications of psoriasis
Erythroderma
| Psychological and social effects
99
Causes of urticaria, angioedema and anaphylaxis
```
Idiopathic
Food
- nuts
- sesame seeds
- shellfish
- dairy
Drugs
- penicillin
- contrast media
- NSAIDs
- morphine
- ACE-i
Insect bites
Contact
- latex
Viral or parasitic infections
Autoimmune
Hereditary
```
100
Describe urticaria
Due to local increase in permeability of capillaries and small venules
Large number of inflammatory mediators play a role but histamine derived from skin mast cells = major
Local mediator release from mast cells can be induced by immunological or non-immunological mechanisms
101
Presentation of urticaria
Swelling involving superficial dermis, raising dermis
| Itchy wheals
102
Presentation of angioedema
Deeper swelling involving dermis and subcut tissues
| Swelling of tongue and lips
103
Presentation of anaphylaxis
Bronchospasm
Facial and laryngeal oedema
Hypotension
Can initially present as urticaria and angioedema
104
Management of urticaria, angioedema and anaphylaxis
Antihistamines - urticaria
Corticosteroids - severe acute urticaria and angioedema
Adrenaline, corticosteriods and antihistamines for anaphylaxis
105
Complications of urticaria, angioedema and anaphylaxis
```
Urticaria is normally uncomplicated
Angioedema and anaphylaxis can lead to
- asphyxia
- cardiac arrest
- death
```
