Dermatology Flashcards
1
Q
What is acanthosis nigricans ?
A
Describes symmetrical, brown, velvety plaques that are often found on the neck, axilla and groin.
2
Q
What are some causes of acanthosis nigricans ?
A
T2DM
GI cancer
Obesity
PCOS
Acromegaly
Cushing’s syndrome
Hypothyroidism
Prader willi syndrome
3
Q
What is the pathophysiology of acanthosis nigricans ?
A
Insulin resistance leads to hyperinsulinaemia
This stimulates keratinocytes and dermal fibroblast proliferation via interaction with insulin like growth factor receptor 1.
4
Q
What is a comedone ?
A
Dilated sebaceous follicle
5
Q
What is acne fulminans ?
A
Very severe acne associated with systemic upset ( fever )
6
Q
How is acne fulminans managed ?
A
Hospital admission and oral steroids
7
Q
What is acne vulgaris ?
A
It is characterised by the obstruction of the pilosebaceous follicles with keratin plugs which results in comedones, inflammation and pustules.
8
Q
What are the features of mild acne ?
A
Open and closed comedones with or without sparse inflammatory lesions
9
Q
What are the features of moderate acne ?
A
Widespread non-inflammatory lesions and numerous papules and pustules
10
Q
What are some features of severe acne ?
A
Extensive inflammatory lesions which may include nodules, pitting and scarring
11
Q
What is the management of mild to moderate acne ?
A
12 week course of topical combination therapy
- topical adapalene with topical benzoyl peroxide
- topical tretinoin with topical clindamycin
- topical benzoyl peroxide with topical clindamycin
12
Q
What is the management of moderate to severe acne ?
A
12 week course of the following :
- topical adapalene with topical benzoyl peroxide
- topical tretinoin with topical clindamycin
- topical adapalene with topical benzoyl peroxide + doxycycline or lymecycline
- topical azelaic acid + either doxycycline or lymecycline
13
Q
What are some features of acne that require a referral to a dermatologist ?
A
Patients with acne conglobate
Patients with nodule-cystic acne
Failure to respond to treatment
Acne with scarring
Psychological stress or mental health disorder
14
Q
What is the pathophysiology of acne vulgaris ?
A
Follicular epidermal hyperproliferation resulting in the formation of a keratin plug. This causes an obstruction of the pilosebaceous follicle.
Hormone imbalance may also contribute
15
Q
What is actinic keratoses ?
A
A common premalignant skin lesion that develops as a consequence of chronic skin exposure.
16
Q
What are some features of actinic keratoses ?
A
Small, crusty or scaly lesions
Pink, red, brown
Typically on sun-exposed areas
Multiple lesions may be present
17
Q
What is the management of actinic keratoses ?
A
Prevention of further risk - sun avoidance, sun cream
Fluorouracil cream ( 2-3 weeks )
Topical Diclofenac
Cryotherapy
Curettage and cautery
18
Q
What is Alopecia areata ?
A
A presumed autoimmune condition causing localised well demarcated patches of hair loss.
19
Q
What is the management of Alopecia areata ?
A
Topical or intralesional corticosteroids
Topical minoxidil
Phototherapy
Dithranol
Contact immunotherapy
Wigs
20
Q
What is an example of a sedating antihistamine ?
A
Chlorpheniramine
21
Q
What are some examples of non-sedating antihistamines ?
A
Loratidine
Cetrizine
22
Q
What are antihistamines used to treat ?
A
Allergic rhinitis
Urticaria
23
Q
What are some side effects of sedating antihistamines ?
A
Anti-Muscarinic properties :
- Urinary retention
- dry mouth
24
Q
What is athletes foot ?
A
Also known as tinea pedis
Usually caused by fungi in the genus trichophyton
25
What are some features of athletes foot ?
Scaling, flaking and itching between the toes
26
What is the management of athletes foot ?
Topical imidazole, undecenoate or terbinafine
27
What is a basal cell carcinoma ?
Skin cancer characterised by slow growth and local invasion
The most common skin cancer in the western world
28
What are some features of a BCC ?
Sun exposed sites ( head and neck )
Pearly flesh coloured papule with telangiectasia which may ulcerate leaving a central crater
29
What are some management options for a BCC ?
Surgical removal
Curettage
Cryotherapy
Topical cream - imiquimod or fluorouracil
Radiotherapy
30
What is bowen’s disease ?
A type of precancerous dermatosis that is a precursor to SCC.
Common in the elderly
31
What are some features of bowens disease ?
Red scaly patches
Slow growing
Sun exposed areas
32
What are some management options for bowens disease ?
Topical 5-fluorouracil
Cryotherapy
Excision
33
What is bullous pemphigoid ?
An autoimmune condition causing sub-epidermal blistering of the skin.
It is secondary to the development of antibodies against hemidesmosomal proteins.
34
What are some features of bullous pemphigoid ?
Itchy, tense blisters around the flexures.
Heal without scarring
No mucosal involvement
35
How is bullous pemphigoid diagnosed ?
Skin biopsy
36
What is the management of bullous pemphigoid ?
Oral corticosteroids - mainstay
Topical corticosteroids, immunosuppressants and abx can be used
37
What is a cherry haemangioma ?
Benign skin lesions which contain an abnormal proliferation of capillaries.
38
What are some features of cherry haemangiomas ?
Erythematous papular lesions
Non-blanching
No mucosal involvement
39
What are some features of plaque psoriasis ?
Erythematous plaques covered with a silvery white scale
Extensor surfaces - elbows and knees
Clear delineation between normal and affected skin
40
What are the 2 main types of contact dermatitis ?
Irritant - non-allergen related
Allergic - type 4 hypersensitivity reaction
41
How does irritant contact dermatitis present ?
Erythema is common
Crusting and vesicles are rare
42
How does allergic contact dermatitis present ?
Acute weeping eczema which predominantly affects the margins of the hairline
43
What is the management of allergic contact dermatitis ?
Topical treatment with a potent steroid
44
What is dermatitis herpetiformis ?
An autoimmune blistering skin disorder associated with coeliac disease.
It is caused by deposition of IgA in the dermis.
45
What are the features of dermatitis herpetiformis ?
Itchy, vesicular skin lesions on the extensor surfaces
46
What is the diagnosis of dermatitis herpetiformis made ?
Skin biopsy - shows deposition of IgA in a granular pattern in the upper dermis
47
What is the management of dermatitis herpetiformis ?
Gluten free diet
Dapsone
48
What is a dermatofibroma ?
A common benign fibrous skin lesions.
Caused by the abnormal growth of dermal dendritic histiocyte cells
49
What are some features of dermatofibroma ?
Solitary firm papule or nodule
5-10 mm in size
Overlying skin dimples on pinching the lesion
50
What is eczema herpeticum ?
Describes a severe primary infection of the skin by herpes simplex 1 or 2.
51
What are some features of eczema herpeticum ?
Rapidly progressing painful rash
Monomorphic punched out lesions
52
What is the management of eczema herpeticum ?
Potentially life threatening
Admitted for IV aciclovir
53
What is a mild steroid ?
Hydrocortisone 0.5-2.5%
54
What is a moderate steroid ?
Betamethasone valerate 0.025% - betnovate
55
What are some potent steroids ?
Fluticasone propionate 0.05% - cutivate
Betamethasone valerate 0.1% - betnovate
56
What is a very potent steroid ?
Clobetasol propionate 0.05% - dermovate
57
What is erysipelas ?
A localised skin infection caused by streptococcus pyogenes.
( superificial limited version of cellulitis )
58
What is the management of erysipelas ?
Flucloxacillin
59
What is erythema ab igne ?
A skin disorder caused by over exposure to infrared radiation
60
What are the characteristic features of erythema ab igne ?
Reticulated, erythematous patches with hyperpigmentation and telangiectasia
61
What is erythema multiforme ?
A hypersensitivity reaction that is most commonly triggered by infections.
62
What are some features of erythema multiforme ?
Target lesions
Back of the hands and feet before spreading to the feet
Pruritus can be seen but is mild
63
What are some causes of erythema multiforme ?
HSV
Idiopathic
Mycoplasma
Drugs - penicillin
SLE
Sarcoidosis
Malignancy
64
What is erythema nodosum ?
Inflammation of subcut fat which typically causes tender erythematous nodular lesions
65
What are some causes of erythema nodosum ?
Infection - streptococci, TB
Systemic disease - sarcoidosis, IBD
Malignancy / lymphoma
Drugs
Pregnancy
66
What are some causative organisms of a fungal nail infection ?
Dermatophytes - trichophyton rubrum
Yeasts - candida
Non-dermatophyte moulds
67
What are some risk factors for a fungal nail infection ?
Increasing age
DM
Psoriasis
Repeated nail trauma
68
What are some features of a fungal nail infection ?
Unsightly nails
Thickened rough, opaque nails
69
What are some investigations for a fungal nail infection ?
Nail clippings +/- scrapings of the affected nail
Microscopy and culture
70
What is the management of a fungal nail infection ?
Do not need to treat if asymptomatic
Nail lacquer, terbinafine
71
What is guttate psoriasis ?
May be precipitated by a streptococcal infection 2-4 weeks prior to lesions appearing
72
What are the features of guttate psoriasis ?
Tear drop papules on the trunk and limbs
73
What is the management of guttate psoriasis ?
Spontaneously resolve within 2-3 months
Topical agents
UVB phototherapy
74
What is hereditary haemorrhagic telangiectasia ?
An autosomal dominant condition characterised by multiple telangiectasia over the skin and mucous membrane
75
What are the criteria for diagnosing hereditary haemorrhagic telangiectasia ?
Meet the following 3 :
- epistaxis
- telangiectases
- visceral lesions
- family history
76
What is hidradenitis suppurativa ?
A chronic painful inflammatory skin disorder,
Characterised by the development of inflammatory nodules, pustules and scars
77
What is the pathogenesis of hidradenitis suppurativa ?
Chronic inflammatory occlusion of folliculopilosebaceous units that obstructs the apocrine glands and prevents keratinocytes from properly shedding
78
What are some risk factors for hidradenitis suppurativa ?
Family history
Smoking
Obesity
DM
PCOS
79
What are some features of hidradenitis suppurativa ?
Recurrent painful inflamed nodules - axilla most common site
80
What is the management of hidradenitis suppurativa ?
Encourage good hygiene
Smoking cessation
Weight loss
Acute flares can be managed with steroids
Long term - topical clindamycin
81
What are some complications of hidradenitis suppurativa ?
Sinus tracts, fistulas
Comedones
Scarring
Contractures
Lymphatic obstruction
82
What is Hirsutism ?
Used to describe androgen dependent hair growth in women
83
What is hypertrichosis ?
Being used to describe androgen independent hair growth
84
What are some causes of Hirsutism ?
PCOS
Cushing’s syndrome
Congenital adrenal hyperplasia
Androgen therapy
Obesity
Adrenal tumour
85
What is the management of Hirsutism ?
Advise weight loss
Cosmetics
COCP
Topical eflornithine for face
86
What is hyperhidrosis ?
Excessive production of sweat
87
What is the management of hyperhidrosis ?
Topical aluminium chloride
Iontophoresis
Botulinum toxin
Surgery
88
What is impetigo ?
A superificial bacterial skin infection usually caused by either staph aureus or strep pyogenes.
89
How is impetigo spread ?
Direct contact - scabs
Indirect - toys, clothing
90
What are the features of impetigo ?
Golden, crusted skin lesions typically found around the mouth
Contagious
Common in children
91
What is the management of impetigo ?
Localised :
- Hydrogen peroxide 1% cream
- Topical abx - fusidic acid
Extensive :
- oral flucloxacillin
- oral erythromycin ( if penicillin allergy )
92
What is a keloid scar ?
Tumour like lesions that arise from the connective tissue of a scar and extend beyond the dimensions of the original wound.
93
What are some predisposing factors for keloid scars ?
Ethnicity - dark skin
Young adults
Sites - sternum, shoulder, neck, face, extensor surface of limbs, trunk
94
What is the treatment of keloid scars ?
Early keloid scar - intra-lesional steroids
Excision ( sometimes required )
95
What is keratoacanthoma ?
Benign epithelial tumour - common with advancing age and rare in young people
96
What are the features of keratoacanthoma ?
Initially a smooth dome - shaped papule
Rapidly grows to become a crater centrally filled with keratin
97
How are keratoacanthomas managed ?
Spontaneous regression within 3 months is common
Excision if clinically difficult to exclude SCC
98
What is the koebner phenomenon ?
It describes skin lesions that appear at the site of injury
99
What conditions is the koebner phenomenon seen in ?
Psoriasis
Vitiligo
Warts
Lichen planus
100
What is lentigo maligna ?
A type of melanoma in situ - typically progresses slowly but may become invasive causing melanoma
101
What is leukoplakia ?
A premalignant condition which presents as white, hard spots on mucous membranes of the mouth.
102
What are some differentials of someone presenting with leukoplakia ?
Candidiasis
Lichen planus
103
What can leukoplakia transform into ?
Squamous cell carcinoma
104
What are some features of lichen planus ?
Itchy, papular rash - ‘white lines, pattern
Koebner phenomenon may be seen
Oral involvement
105
What is the management of lichen planus ?
Potent topical steroids
Benzyldamine mouthwash or spray for oral licen planus
106
What is a lipoma ?
A common, benign tumour of adipocytes
107
What is the pathophysiology of lipomas ?
Generally found in subcutaneous tissues
108
What are some features of lipomas ?
Lumps :
- smooth
- mobile
- painless
109
What is the management of lipomas ?
Observation
Can be removed
110
What is livedo reticularis ?
Describes an purplish, non-blanching, reticulated rash caused by obstruction of the capillaries resulting in swollen venules.
111
What are the causes of livedo reticularis ?
Idiopathic
SLE
Polyarteritis nodosa
Antiphospholipid syndrome
Ehlers-danlos syndrome
112
What is the most common type of melanoma ?
Superficial spreading melanoma
113
What are the main diagnostic features of melanoma ?
Changes in size, shape and colour
Inflammation
Oozing or bleeding
114
How is a diagnosis of melanoma made ?
Excision biopsy
115
What is the management of melanoma ?
Excision with extended margins
116
What is molluscum contagiosum ?
A common skin infection caused by the molluscum contagiosum virus ( MCV ).
Pinkish or pearly white papules with central umbilication.
117
How is molluscum contagiosum transmitted ?
Direct - close personal contact
Indirect - via fomites ( contaminated surfaces )
118
What are the features of molluscum contagiosum ?
Pinkish or pearly white papules with central umbilication
Anywhere on the body
119
What is some self care advice for molluscum contagiosum ?
Reassure people it is self limiting
Resolves within 18 months
Lesions are contagious
Don’t scratch the lesions
120
What is the management of molluscum contagiosum ?
Treatment is usually required
If troublesome - simple trauma or cryotherapy can be used.
121
What is pellagra ?
Caused by niacin deficiency with classical features of dermatitis, diarrhoea and dementia.
122
What are some causes of pellagra ?
Consequence of isoniazid therapy - as it inhibits the conversion of tryptophan to niacin
Alcoholics
123
What are some features of pellagra ?
Dermatitis
Diarrhoea
Dementia, depression
Death if not treated
124
What is pityriasis rosea ?
Describes an acute, self limiting rash which tends to affect young adults.
125
What are some features of pityriasis rosea ?
Herald patch usually on trunk followed by erythematous oval scaly patches
126
What is the management of pityriasis rosea ?
Self limiting - usually resolves after 6-12 weeks
127
What are port wine stains ?
Vascular birthmarks that tend to be unilateral.
Deep red or purple in colour
Do not resolve spontaneously
128
What is the management of port wine stains ?
Cosmetic camouflage
Laser therapy
129
What are some conditions that cause pruritus ?
Liver disease
Iron deficiency anaemia
Polycythaemia
CKD
Lymphoma
130
What is psoriasis ?
Common and chronic skin disorders which generally presents with red, scaly patches on the skin
131
What are some complications of psoriasis ?
Psoriatic arthropathy
Increased incidence of metabolic syndrome, CVD, VTE
Psychological distress
132
What are some nail changes seen in psoriasis ?
Pitting
Onycholysis
Loss of nail
Subungal hyperkeratosis
133
What are some exacerbating factors of psoriasis ?
Trauma
Alcohol
Drugs - beta blockers, lithium, anti malarials, NSAIDs
Withdrawal of systemic steroids
134
What can trigger guttate psoriasis ?
Streptococcal infection
135
What is the management of plaque psoriasis ?
Potent corticosteroids
Vitamin D analogue
Phototherapy
Oral methotrexate - systemic therapy
136
What is the management of scalp psoriasis ?
Potent topical corticosteroids
137
What is purpura ?
Describes bleeding into the skin from small blood vessels that produces a non-blanching rash.
138
Why should children with a new purpuric rash be admitted immediately for investigations ?
May be a sign of meningococcal septicaemia or acute lymphoblastic leukaemia.
139
What are some potential causes of purpura in children ?
Meningococcal septicaemia
ALL
Congenital bleeding disorders
ITP
Henoch-schonlein purpura
Non-accidental injury
140
What are some potential causes of purpura in adults ?
ITP
Bone marrow failure
Senile purpura
Nutritional deficiencies
141
What is pyoderma gangrenosum ?
A rare, non-infectious inflammatory disorder but mainly affects the lower legs.
142
What are some causes of pyoderma gangrenosum ?
Idiopathic
IBD
RA
SLE
Haematological
143
What are some features of pyoderma gangrenosum ?
Location - lower limb
Small pustule, red bump which then breaks down resulting in an ulcer - painful
Fever
Myalgia
144
What is the management of pyoderma gangrenosum ?
Oral steroids
Immunosuppressive therapy - Ciclosporin and infliximab
145
What is isotretinoin ?
An oral retinoid used in the treatment of severe acne.
146
What are some adverse effects of retinoids ?
Teratogenicity - women ideally should be on 2 forms of contraception
Dry skin, eyes and mouth
Low mood
Raised triglycerides
Hair thinning
Nose bleeds
147
What is rosacea ?
A chronic skin disease of unknown aetiology
148
What are some features of rosacea ?
Typically affects nose, cheeks and forehead
Flushing
Telangiectasia
Later develops into persistent erythema with papules and pustules.
149
What is the management of rosacea ?
High factor suncream
Topical brimonidine gel for flushing
Mild to moderate - topical ivermectin
Moderate to severe - topical ivermectin + oral doxycycline
150
What is scabies ?
It is caused by the mite sarcoptes scabiei and is spread by prolonged skin contact. They burrow into the skin, laying its eggs into the skin.
151
What are some features of scabies ?
Widespread pruritus
Linear burrows on the side of fingers, interdigital and flexor aspects of the wrist.
Excoriation
152
What is the management of scabies ?
Permethrin 5% - first line
Malathion 0.5% - second line
Avoid close physical contact
153
What are some features of sebaceous cysts ?
Location - anywhere but most common scalp, ears, back, face and upper arm
Typically contain a punctum
154
What is seborrhoeic dermatitis ?
Chronic dermatitis thought to be caused by an inflammatory reaction related to a proliferation of a normal skin inhabitant.
155
What are some features of seborrhoeic dermatitis ?
Eczematous lesions on the sebum-rich areas - scalp, periorbital, auricular and nasolabial folds
Otitis externa and blepharitis
156
What are some associated conditions to seborrhoeic dermatitis ?
HIV
Parkinson’s disease
157
What is the management of scalp seborrhoeic dermatitis ?
First line - ketoconazole 2% shampoo
158
What is the management of face and body seborrhoeic dermatitis ?
Topical anti fungals - ketoconazole
Topical steroids
159
What are seborrhoeic keratoses ?
Benign epidermal skin lesions in older people
160
What are some features of seborrhoeic keratoses ?
Large variation in colour from flesh to light brown to black
Stuck on appearance
Keratotic plugs
161
What is the management of seborrhoeic keratoses ?
Reassurance as it’s benign
Removal - curettage, cryotherapy and shave biopsy
162
What can cause shin lesions ?
Erythema nodosum
Pretibial myxoedema
Pyoderma gangrenosum
163
What is pretibial myxoedema associated with ?
Graves’ disease
164
What is shingles ?
An acute, unilateral painful blistering rash caused by reactivation of the varicella-zoster virus.
165
What are the risk factors for shingles ?
Increasing age
HIV
Immunosuppressive conditions - steroids and chemotherapy
166
What dermatomes are most commonly affected in shingles ?
T1 - L2
167
What are some features of shingles ?
Prodromal period - burning pain for 2-3 dyas
Erythematous, macular rash becomes vesicular
168
What is the management of shingles ?
Remind patient they are potentially infectious - avoid pregnant women and Immunosuppressed
Analgesia - paracetamol and NSAIDs
Oral corticosteroids
Fast antivirals
169
What are some complications of shingles ?
Post-herpetic neuralgia
Herpes zoster ophthalmicus
Ramsey hunt syndrome
170
What are the skin manifestations of SLE ?
Photosensitive ‘butterfly’ rash
Discoid lupus
Alopecia
171
What is spider naevi ?
Describes a central red papule with surrounding capillaries.
The lesions blanch upon pressure
172
What is the difference between spider naevi and telangiectasia ?
Spider naevi fill from the centre while telangiectasia from the edge.
173
What are some associations of spider naevi ?
Childhood
Liver disease
Pregnancy
COCP
174
What are some risk factors for SCC ?
Excessive exposure to sunlight
Actinic keratoses and bowen’s disease
Immunosuppression
Smoking
175
What are some features of SCC’s ?
Typically on sun-exposed sites
Painless, ulcerate nodules
May have a cauliflower-like appearance
Bleeding
176
What is the management of SCC’s ?
Surgical excision with 4mm margins
177
What is stevens-Johnson syndrome ?
A severe systemic reaction affecting the skin and mucosa that is almost always caused by a drug reaction.
178
What are the causes of stevens-Johnson syndrome ?
Penicillin
Sulphonamides
Anti-epileptics
Allopurinol
NSAIDs
COCP
179
What are some features of stevens-Johnson syndrome ?
Maculopapular rash with target lesions
- may develop into vesicles and bullae
Mucosal involvement
Fever and arthralgia
180
What is the management of stevens-Johnson syndrome ?
Hospital admission is required for supportive treatment
181
What is tinea ?
A term given to dermatophyte fungal infections
182
What is tinea capitis ?
Scalp ringworm - trichophyton tonsurans
183
What are some features of tinea capitis ?
If untreated a raised, pustular, spongy/boggy mass called a kerion may form
Scarring Alopecia may occur
184
What is the management of tinea capitis ?
Oral anti fungals - terbinafine
Topical ketoconazole shampoo
185
What causes tinea corporis ?
Caused by trichophyton rubrum
186
What are the features of tinea corporis ?
Well-defined annular erythematous lesions with pustules and papules.
187
What is the management of tinea corporis ?
Oral fluconazole
188
What are the features of tinea pedis ?
Characterised by itchy, peeling skin between the toes
Common in adolescence
189
What is toxic epidermal necrolysis ?
A potentially life-threatening skin disorder that is most commonly seen secondary to a drug reaction.
Looks like a scalded appearance
190
What are some features of toxic epidermal necrolysis ?
Systemically unwell - pyrexia and tachycardia
Positive nikolsky’s sign - the epidermis separates with mild lateral pressure
191
What are some drugs known to induce toxic epidermal necrolysis ?
Phenytoin
Sulphonamides
Allopurinol
Penicillins
Carbamazepine
NSAIDs
192
What is the management of toxic epidermal necrolysis ?
Stop precipitating factors
Supportive care
IV immunoglobulin
193
What is urticaria ?
Describes a local or generalised superficial swelling of the skin.
Most common cause is allergy
194
What are the features of urticaria ?
Pale, pink raised skin - hives, wheals
Pruritic
195
What is the management of urticaria ?
First line - Non-sedating antihistamines - loratadine or cetirizine
Sedating antihistamine - chlorphenamine ( used at night )
196
Where is venous ulceration most commonly seen ?
Medial malleolus
197
What are some investigations for venous ulcerations ?
Ankle - brachial pressure index ( ABPI )
Normal is 0.9-1.2
198
What is the management of venous ulceration ?
Compression bandaging
Oral pentoxifylline - a peripheral vasodilator
199
What is vitiligo ?
An autoimmune condition which results in the loss of melanocytes and consequent depigmentation of the skin.
200
What are some associated conditions of vitiligo ?
T1DM
Addison’s disease
Thyroid disorders
Pernicious anaemia
Alopecia areata
201
What are the features of vitiligo ?
Well-demarcated patches of depigmented skin
Peripheries tend to be most affected
Trauma may precipitate new lesions
202
What is the management of vitiligo ?
Suncream for affected areas
Camouflage make up
Topical corticosteroids
203
What are some features of zinc deficiency ?
Acrodermatitis - red, crusted lesions
Alopecia
Short stature
Hypogonadism
Hepatosplenomegaly
