derm Flashcards
Mild acne vulgaris
Open and closed comedones with or without sparse inflammatory lesions
Moderate acne vulgaris
Widespread non-inflammatory lesions and numerous paperless and pustules
Severe acne vulgaris
Extensive inflammatory lesions, which may include nodules, pitting and scarring
Single topical therapy for acne
Topical retinoids and benzoyl peroxide
*for mild do not use antibiotics
For moderate acne management
Topical antibiotic, benzoyle peroxide, topical retinoid
Oral antibiotics for acne vulgaris
Tetracyclines though AVOID in pregnant women
How to differentiate between a pyogenic granuloma may mimic amelanotic melanoma
a pyogenic granuloma may mimic the amelanotic melanoma but is caused by trauma
Risk factors for developing a pyogenic granuloma
Trauma
Pregnancy
More common in women and young adults
Found most commonly on head/neck/trunk and hands
Management of pyogenic granuloma
Lesions associated with pregnancy = resolve spontaneously
Other = curettage, cauterisation, cryotherapy, excision
What are the 2 types of contact dermatitis
irritant contact dermatitis - non-allergic due to weak acids or alkalis often seen on hands
Allergic contact dermatitis - type IV hypersensitivity - rare - seen on scalp after hair dyes = potent steroids are indicated
Unusual cause of contact dermatitis - irritant
Cement
Buzzwordy = acute onset, tear-drop/small spot scale papules, trunk and limbs, young person, following a throat infection (streptococcal)
guttate psoriasis
Treatment of guttate psoriasis
most cases resolve spontaneously within 2-3 months
UVB phototherapy
Topical agents same as psoriasis
What is dactylitis
Diffuse swelling of the digits
What is only onycholysis
Painless detachment of the nail from the nail bed
What are the nail changes associated with psoriasis
Nail pitting
Onycholysis
BUZZWORD** pearly rolled edges with telangiectasia surrounds central crater
basal cell carcinoma
Topicals for basal cell carcinoma
Imiquimod, fluorouracil
What class of drugs exacerbate psoriasis
Beta blockers
NSAIDs
ACEi
TNF-a
Anti-malarials
Also lithium
Which acne medication is contraindicated in pregnancy
Oral isotretinoin
What are main medication to treat acne vulgaris
Topical retinoids
Benzoyl peroxide
What is the antibody associated with dermatitis herpetiforms
Anti-tissue transglutaminase antibody
What is dermatitis herpetiformis
Itchy vesicular rash that presents on elbows knees and buttocks and is associated with Coeliac
What malignancy is a renal transplant patient most at risk of in the future
Skin cancer - squamous cell carcinoma of the skin
Features of scabies
Widespread pruritus
Linear burrows on the side of fingers, interdigital webs and flexor aspects of the wrist
Scratching = excoriation, infection
Management for scabies - first line
Permethrin 5%
What is erythema nodosum
Inflammation of subcutaneous fat
Typically causes tender erythematous, nodular lesions
Usually occurs over shins - may occur forearms thighs
- ‘hives’ ‘wheals’ ‘nettle rash’
= urticaria
first line = antihistamines
First line for seborrhoeic dermatitis
Topical ketoconazole (anti-fungals)
What causes seborrhoeic dermatitis
Malassezia furfur
First line for pityriasis versicolor
Ketoconazole shampoo (anti-fungal)
Which medications can cause a flare up of psoriasis
Beta-blockers
Lithium
Anti-malarials (Chloroquine etc)
NSAIDs
ACEi
Infliximab
*exclamation mark hairs
= alopecia areata
What skin condition is associated with IBDs
Pyoderma gangrenosum
Skin problems make up x percent of GP consultations
15-23%
What is the enzyme deficiency in acute intermittent porphyria
PBG deaminase
Description of the hypersensitivity reactions …
Type I = immediate hypersensitivity
Type II = direct cell killing
Type III = immune complex mediated
Type IV = delayed type hypersensitivity
Function of collagen
Vitamin D metabolism
Function of subcutaneous fat
energy storage
Function of collagen
Tensile strength
Function of Basal cells
Epidermal proliferation
Function of mast cells
Release of inflammatory mediators
At what point of gestation do sweat glands develop
6 months
Where do melanocytes migrate from (gestation)
From: Neural crest
To: skin
T/F blashko’s lines develop in the distribution of cutaneous nerves
F - they are developmental
Which layer of the skin is the most metabolically active ?
Basal layer
Features of mucosal membranes
Highly specialised for function ie
They are often affected by skin disease, they are keratinised, have sensory functions (taste) and often contain glands
Why do steroids need to be lipophilic ?
To allow for passive diffusion across the plasma membrane where they combine with cell receptors and bind to steroid responsive elements in the DNA
They are anti-proliferatives, anti-inflammatory and vasoconstrictive
Describe which arteries to get from lungs to big toe
pulmonary vein > left side of the heart > aorta > abdominal aorta > common iliac artery > external iliac artery > femoral artery > popliteal artery > dorsalis pedis
Which 3 things are important in maintaining good peripheral vasculature
Venous valves
Pulse pressure
The muscle pump
How many days does it take for a cell to migrate from basal layer to keratin layer
28 days (later ahah lol :/ )
How many cells thick is the granular layer
2-3 cells thick
What percent of the keratin layer is keratin and filaggrin
80%
Which component of MRSA causes necrotising fasciitis
PVL - panton valentine leukocidin
Features of Langerhan cells
Formed in bone marrow
Migrate throughout epidermis and dermis
Travel via lymphatics to present antigen in lymph nodes
Describe the route to get from big toe to heart
deep plantar vein > great saphenous > femoral vein > external iliac vein > common iliac > abdominal vena cava > inferior vena cava > RA
What is this
Crust
What is this
Erosion
What is this
Scale
What is this
Lichenification
What is this
maceration
Breslow thickness arises from what layer in the skin
Granular layer
What does eczema look like on histology
What does spongiosis look like on histology
What is Buerger’s disease
A vasculitis disease most common in young males who smoke
-foot pain during exertion is a symptoms
Can lead to hypercellular occlusive thrombus
*tortuous corkscrew collaterals may reconstitute patent segments of the distal tibial or pedal vessels
*corkscrew shaped collateral vessels distally on angiogram
Buergers disease
What is Takayasu arteritis
Can be divided into: acute and chronic
In chronic - upper limb claudication
In later stages the vessels will typically show changes of intimacy proliferation, together with band fibrosis of the intima and media
what are the large vessel vasculitis
Temporal arteritis
Takayasu arteritis
what are the medium vessel vasculitides
Polyarteritis nodosa
Kawasaki disease
what are the small cell vasculitides
ANCA - associated (GPA, eGPA - churgstrauss)
Immune complex - henoch schonlein, anti-GBM
What is the most common associated malignancy of Acanthosis nigricans
Gastrointestinal adenocarcinoma
Investigation for distal limb ulcers
Ankle-brachial pressure index
Normal range = 0.9-1.2
Anything below or above could be due to arterial disease
*target lesions
=erythema multiforme
Child with atopic eczema has presented with a rapidly progressing painful rash, painful clustered blisters are noted
What is the most appropriate thing to do?
Admit to hospital for life-saving aciclovir
This child is presenting with eczema herpeticum
How does insulin resistance cause acanthosis nigricans
It causes hyperinsulineamia which stimulates keratinocytes and dermal fibroblast proliferation
This proliferation causes the characteristic darkened, thickened skin
What skin condition is due to autoimmune melanocyte destruction
Vitiligo
What does bullous pemphigoid look like
Treatment of bullous pemphigoid
Oral corticosteroids, topical “, immunosuppressants, antibiotics
what would immunofluorescence show for bullous pemphigoid
IgG and C3 at the dermoepidermal junction
Treatment to target dermatophyte nail infections
Oral terbinafine
Dermatophyte nail infection eg trichophyton rubrum
*shiny orange peel skin
Graves’ disease - Pretibial myxoedema
High electrical voltage burns are associated with what disease
Rhabdomyolysis
*crazy high creatinine
Rhabdomyolysis
what is curling’s ulcer
A stress ulcer may occur in the duodenum of burn patients and these are more common in children
Positive Ziehl-Nielsen staining for acid-fast bacilli ?
Think TB
What is a cause of erythema nodosum
TB
Patients will come in with the respective rash but also with haemoptysis, fever, weight loss, coughing
What is erythema nodosum
Inflammation of subcutaneous fat
What is nikolskys sign ?
Epidermis separating with mild lateral pressure
+nikolysky’s sign
Think : toxic epidermal necrosis
what is toxic epidermal necrosis
It is a potentially life-threatening skin disorder that is most commonly seen secondary to a drug reaction
Skin = scalded over an extensive area
Drugs that induce toxic epidermal necrosis
Phenytoin
Penicillins
Management of toxic epidermal necrolysis
Iv immunoglobulins
Features of rosacea
Appears of nose, cheeks and forehead
Flushing, erythema, telangiectasia —> papules and pustules
Sunlight may exacerbate symptoms
What is koebners phenomenon
Causes lesion to appear at site of injury
What is exhibited here
Molluscum contagiosum - virus
How long does pityriasis rosea rash last ?
6-12 weeks
What is alopecia areata
An autoimmune condition causing localised, well demarcated patches of hair loss
At the edge of the hair loss there may be small broken ‘exclamation mark hairs’
PMH of crohns and presents with a painful ulcer ?
Pyoderma gangrenosum
Itchy rash - purple, raised and has fine white lines on the surface
Lichen planus
*blue sclera
Osteogenesis imperfecta - type I collagen
What precedes pityriasis rosea
Viral infection
Virus associated with pityriasis rosea
Herpes hominis virus 7
According to NICE guidelines how long should you wait before starting a second course of topical hydrocortisone
4 weeks
What is pellagra
Caused by niacin deficiency = dermatitis, diarrhoea, dementia
Can be caused by isoniazid therapy
This rash is non-itchy - what is it
Erythema multiforme
= giant , non- itchy , target lesions
This rash is usually caused by by infections or drug interactions ie amoxicillin
“Herald patch” followed by later (a week) by additional lesions
Lethargy + limited lesions to the trunk
= stereo-typical presentation of what ?
Pityriasis rosea
Drugs that exacerbate psoriasis
Beta blockers , lithium , anti-malarials (chloroquine and hydroxychloroquine) , NSAIDs , ACEi + infliximab
*red or black lump that oozes or bleeds, and is located on sun exposed skin
Nodular melanoma
What to do if eczema herpeticum is suspected
It is potentially life threatening in children and so they should be admitted into hospital and given IV aciclovir
What is the most common side effect of isotretinoin
Dry skin
Iron deficiency anaemia
*heliotrope rash
Dermatomyositis
Initial investigation of dermatomyositis and polymyositis
Creatinine kinase
Dermatomyositis + polymyositis definitive diagnosis
Muscle biopsy
*gottrons papules
Dermatomyositis
What are the common complications of toxic epidermal necrolysis
Fluid loss
Electrolyte imbalance
Treatment for Toxic epidermal necrolysis
Supportive care - volume loss and electrolytes
IV immunoglobulins
Drugs known to cause toxic epidermal necrolysis
Phenytoin
Sulphonamides
Allopurinol
Penicillin - main one
NSAIDs
Carbamezapine
Can you prescribe oral isotretinoin in the GP practice ?
No - can only be prescribed under specialist care therefore if you suspect patient has severe acne then refer to dermatology
What should benzoyl peroxidase and retinoids be co-prescribed with
Antibiotics oral
Management of venous ulcers
Compression bandaging
Oral pentoxifylline
*deep, dry, punched out ulcer
Arterial ulcer
Would also present with burning pain in the leg
Ulceration over bony prominence
(Lateral malleolus)
*ulcer round medial malleolus / gaiter region
Venous ulcer
What is the organism that causes Athlete’s foot
Trichophyton
First line for athletes foot
Topical imidazole, undecenoate or terbafine
*monomorphic punched out erosions - circular, depressed ulcerated lesions
Eczema herpeticum
What are the two premalignant lesions to melanoma
Bowens
Actinic keratosis
What is erythema ab igne
A lesion caused by infrared radiation and is commonly associated with hot water bottles or open fire
What is this ?
Erythema ab igne
(Overexposure to infraredradiation)
If heat source isn’t removed in erythema ab igne , what could the patient go on to develop ?
Squamous cell carcinoma
1st line for lichen planus
Topical steroids
*antistreptolysin - O titre raised
Erythema nodosum
Common causes of erythema nodosum
Pregnancy
Streptococcal infection
*honeycomb arrangement on immunofluorescence
Pemphigus vulgaris
Virus infection of HSV-1 can cause what ?
Eczema herpeticum
*painless purple lesion associated with HHV-8
Kaposi’s sarcome
Management of scabies
2 treatments of Permethrin
All close contacts will require treatment
Management of impetigo
Topical fusidic acid + flucloxacillin
Patients are no longer contagious: after lesions have crusted over OR have been on 48 hours of treatment
First line for hyperhidrosis
Topical aluminium chloride
What is an associated complication of acne rosea
Blepharitis
Management of rosacea
Simple = concealer and high factor sunscreen
With flushing but limited telangiectasia = topical brimonidine gel
With mild - moderate papules = topical ivermectin is first line
With moderate - severe = dual therapy of ivermectin and oral doxycycline
(Prominent telangiectasia = laser therapy)
Management of vitiligo
Sunblock
Camouflage make up
Topical corticosteroids
(Topical tacrolimus and phototherapy)
1st line for lichen planus
Topical betamethasone
*net like pattern of reddish blue skin discolouration that is non-blanching
Livedo reticularis
Should psoriasis patients take a break from their topical corticosteroids ?
Yes - aim for a 4 week break in between courses of topical corticosteroids
What are the hyperinsulinaemic states (Acanthosis nigricans)
T2DM
GI cancer
Obesity
PCOS
Acromegaly
Cushings disease
Prader willi
Acute rash on face and neck , multiple red monomorphic blisters and erosions
Systemic upset - lymphadenopathy and fever
Eczema herpeticum
A serious complication of eczema caused by Herpes simplex virus
Most common nail change in psoriasis
Nail pitting
= squamous cell carcinoma
