Dermatology Flashcards
What is the management of extensive fungal nail infection by dermatophytes?
- Oral terbinafine
How should a child with new-onset purpura be managed?
Immediate referral to secondary care to exclude ALL
Where are keloid scars most common?
Sternum
What is the management of athletes foot?
- Topical miconazole
- terbinafine
What medications exacerbate plaque psoriasis?
Beta blockers, lithium, antimalarias, NSAIDS and ACE
What should be used for long-term psoriasis?
Calcipotriol
What is pemphigoid gestationis?
Pruritic blistering lesions which in the peri-umbilical region and can then spread to trunk, back buttocks and arms in the 2nd/3rd trimester
When does pemphigoid gestationis present?
In the second/third pregnancy
How is pemphigoid gestationis managed?
Oral corticosteroids
What can make perioral dermatitis worse?
Topical steroids
What is the first line management of venous ulcers?
Compression bandaging
What is a rare side effects of penicllins?
Toxic epidermal necrolysis
What is the most common malignancy associated with acanthosis nigricans?
gastrointestinal adenocarcinoma
What are some causes of acanthosis nigricans?
- T2DM
- PCOS
- Obesity
- Cushing’s disease
- Acromegaly
- COCP
purple, polygonal, pruritic papules suggest what?
Lichen planus
What is a port wine stain?
A vascular birthmark: deep red or purple colour usually over the cheek
What is a strawberry naevus?
A soft raised vascular swelling which is bright red in colour
What is a salmon patch?
A flat dull-red area usually on the face and neck, usually in the midline which causes no symptoms
What derm feature is associated with Sturge Webber syndrome?
Port wine stain
What is pityriasis versicolor?
A superficial fungal (Malassezia) infection which affects the trunk causing pink/brown patches, sometimes after a suntan
What is the management of pityriasis versicolor?
Topical antifungal: ketoconazole
Salmon patch vs port wine stain?
Salmon patch will usually self resolve
What is toxic epidermal necrolysis?
A emergency scaled skin appearance usually secondary to a drug reaction
How does toxic epidermal necrolysis present?
- Systemically unwell patient
- Positive Nikolsky sign: epidermis separates with mild lateral pressure
What drugs are known to induce toxic epidermal necrolysis?
- Phenytoin
- Allopurinol
- Penicillins
- NSAIDs
- Carbamazepine
How is toxic epidermal necrolysis managed?
- Stop trigger
- Supportive care: fluid loss and electrolyte derangements are complications
- IV immunoglobulins are first line
What is pityriasis rosea?
An acute self limiting rash which affects younger people
How does pityriasis rosea present?
- Herald patch on trunk
- Followed by smaller red macules
- Lethargy
- Christmas tree distribution as on upper parts of arms and legs
Bowens vs SCC?
SCC will ulcerate, grow over weeks-months and may bleed
What is the management of Bowens?
Topical 5-fluorouracil
A rapidly progressing painful rash in children with atopic eczema suggests what?
Eczema herpeticum
How is eczema herpeticum managed?
Admission for IV aciclovir with urgent derm and opthal review
What are causes of erythema nodosum?
NO cause
Drugs
OCP
Sarcoidosis
UC and Crohns
Microorganisms such as TB, Strep and Chlamydia
What is erythema ab igne?
A skin disorder associated with over exposure to infrared radiation: hot water bottles or open fires
How should patients with moderate/severe papules in rosacea be managed?
Topical ivermectin and oral doxycycline
What is the management of refractory pain in shingles?
Prednisolone
What can iron deficiency anaemia cause?
Pruritus
What is the management of athletes foot?
- Topical imidazole
- Terbinafine
What is a complication of burns?
Curlings ulcers - acute gastric ulcers which develop in response to physiological stress: usually present with vomiting blood
What pathogen causes eczema herpeticum?
Herpes simplex 1/2
When to use skin patch vs skin prick test?
Skin patch - used for contact dermatitis
Skin prick - used for immediate hypersensitivity reactions e.g. food and resp allergies
Skin infection occurring 2-4 weeks after a strep infection?
Guttate psoriasis
‘tear drop papule on the trunk and limb’
Guttate psoriasis
What is livedo reticularis?
- A non-blanching, reticulated rash caused by obstruction of the capillaries
- Can be idiopathic or part of SLE, Ehlers-Danlos
non-healing painless ulcer associated with a chronic scar
Squamous cell carcinoma
How long will people with shingles be infectious?
Until the vesicles have crusted over - 5-7 days after onset
Steroid treatment in psoriasis?
Aim for 4 week break in between courses
What is the main reason for using antivirals for shingles?
Reduce post herpetic neuralgia
What phenomenon does psoriasis exhibit?
Koebner phenomenon - new skin lesions form at the site of cutaneous injury
What is the most important prognostic factor with malignant melanoma?
Depth of the lesion
intensely pruritic rash on the palms and soles
pomphlyx eczema
What term condition can isoniazid cause?
Pellagra - dermatitis, diarrhoea and dementia
How is rosacea managed?
Predominant flushing: topical brimonidine
Mild-moderate papules: topical ivermectin
Moderate-severe papules: tropical ivermictin + oral doxycycline
single well-demarcated, erythematous circular patch with a raised edge and central hypopigmentation
tinea corpis
Management of severe urticaria?
Short course of oral steroids plus anti-histamine
What should be screened for before starting isotretinoin?
Mental health conditions/Pregnany
What is a wheal?
Transient, raised lesions due to underlying dermal oedema -> urticaria
What does histology of eczema show?
IgE mediated response
- Epidermal acanthosis
- Hyperkeratosis
- Parakeratosis
red scaling plaques in sun exposed areas of skin
Discoid lupus
Actinic keratosis vs sebhorreic keratosis?
AK - lesions lighter in colour + more in line with the skin, SK - lesions will be much darker + stuck on appearance
What can be used for patients with severe childhood eczema?
Wet wrapping
Flu-illness, dry cough, target shaped lesions + anaemia
Erythema multiforme caused by Mycoplasma pneumonia
Which organisms cause necrotising fasciitis?
Type 1 - mixed
Type 2 - strep pyogenes
What are risk factors for malignant melanoma?
- Fair complexion
- FH
- Sunburn
- Sun exposure
What are sites where malignant melanoma can occur?
- Choroid of the eye
- CNS
- GI tract
- Neck
What are features of BCC?
- Small, pearly white lesion
- Rolled edge
- Central ulcer
- Can be pigmented
What surgical technique can be used for BCC?
Mohs micrographic surgery
What is the pathophysiology of acne?
Increased sebum production leads to the pilosebaceous follicles becoming blocked and infected
Which bacteria is involved with acne?
Propionbacterium acnes
What are S/E of isotretinoin?
Dry skin, dry eyes, depression, migraine, muscle aches
What is the name for SCC carcinoma in situ?
Bowens
What anatomical sites on head and neck give worst prognosis for SCC?
Ear and lip
What is the management of lichen sclerosus?
Topical steroids and emollients
What does lichen sclerosus increase the risk of
Vulval cancer
Most common organism for cellulitis?
Strep pyogenes then staph aureus
Incredibly itchy blisters + papules in someone with coeliac?
Dermatitis herpetiformis
What classification system is used for patients with cellulitis?
Eron
What is the Abx of choice for severe cellulitis?
Co-Amox / Clindamycin
Target lesions on back of hands/feet spreading to limbs?
Erythema multiforme
What is erythema nodosum?
Painful inflammation of the sub cut fat more common in females
Lichen planus vs lichen sclerosus
Planus - can affect inside the vagina, Sclerosus will only affect the external genitals
Planus - purpuric papular lesions, Sclerosus - small, white plaques
‘saw tooth pattern of epidermal hyperplasia, T-cell infiltration and reduced melanocytes’
Lichen planus
Round, pearly papules in crops in children?
Think Molluscum - no treatment needed
Erythema multiforme vs pityriasis vericolor?
Pityriasis - white/brown patches with dry scaly skin usually on trunk
Erythema - red, round lesions
Papular rash around abdomen/wrist/inner thigh which itches worse at night?
Scabies - treat with Permethrin for all household members
Flaky rash on face/scalp/trunk which is not itchy?
Seborrheic Dermatitis
Which fungus causes seborrheic dermatitis?
Malassezia furfur
What conditions are associated with seborrheic dermatitis?
Parkinsons / HIV
What are common complications of seborrheic dermatitis?
Otitis externa / Blepharitis
Most common and most aggressive form of melanoma?
Common - superficial spreading
Aggressive - Nodular
What is the management of actinic keratoses?
- Avoid sun
- Fluorouracil cream
What is erythroderma?
Complex process leading to rapid epidermal cell turnover -> large desquamated area which is red and painful
What is the management of erythroderma?
Urgent derm referral with admission to burns unit for emollients, fluids and wet balances
What can often cause erythroderma?
Drugs like sulphonylureas, isoniazid and sulphonamides
Which antibiotic causes red man syndrome?
Vancomycin
Signs of psoriasis on nails?
- Nail pitting
- Oncholysis
- Oil drop sign
What sign in psoriasis where pinpoint bleeding occurs when scales are scraped?
Auspitz sign
What are the ABCDE of lesions?
Asymmetry
Border
Colour change
Diameter > 6mm
Evolving lesion
What are cardinal signs of inflammation?
Dolor
Calor
Rubor
Tumour
Loss of function
What autoimmune diseases are associated with dermatitis herpetiformis?
- Coeliac
- Vitiligo
- Addisons
- T1DM
What are skin manifestations of liver disease?
- Flushing
- Hyperpigmentation
- Palmar erythema
- Jaundice
- Spider naevi
What are nail manifestations of liver disease?
- Clubbing
- Koilonychia
- Leukonychia
What is seborrheic keratosis?
Benign warty epidermal growths which occur in older patients - can be removed by cryotherapy/curettage
What is folliculitis?
Inflammatory condition of hair follicles caused by Staph aureus
Crusty lesion which may bleed easily when bumped or scratched?
SCC
What type of hypersensitivity reaction is scabies?
delayed type IV
How long can pruritus persist for with scabies?
6 weeks
Red or black lump, oozes or bleeds, sun-exposed skin
Nodular melanoma
Acute onset of tear-drop scaly papules on trunk and limbs
Guttate psoriasis
Afro-Carribean with nodule not on sun exposed area?
Think acral lentiginous melanoma
How often should people with scabies be treated?
Twice with treatments one week apart
PUVA therapy is associated with what?
SCC
Hard swelling near the umbilicus?
Think Sister Mary Joseph nodule - gastric cancer
Rash improving with sunlight?
Psoriasis
Small lower limb ulcer which develops into deep ulcer following minor trauma?
Think pyoderma gangrenosum - treat with prednisolone
What is pyoderma gangrenosum associated with?
- Diabetes
- IBD
- GPA
- Sarcoidosis
- Thyroid disorders
widespread raised papules with a central umbilication on his trunk, face, hands, legs and feet
Molluscum contagiosum
What can persistent molluscum be a sign of?
Immunocompromise -> HIV testing needed
Layers of the skin?
- Epidermis
- Dermis
- Subcut tissue
Topical corticosteroids can cause what?
Skin depigmentation in patients with darker skin
Bullous pemphigoid vs pemphigus vulgaris?
BP - elderly patient with deep blisters and no mucosal involvement -> treat with topical steroids
PV - middle aged patient with superficial blisters, mucousal involvement -> treat with oral steroids/immunosuppression
pruritic wheals?
Urticaria
red, scaly rash on the face and scalp which is itchy
Sebhorreic dermatitis
What is the most common infection which cause erythema multiforme?
Herpes simplex virus
What is vitiligo?
Loss of melanocytes in the skin’s epidermis
What causes erythroderma?
- Dermatitis
- Psoriasis
- Drug allergies
- Idiopathic
What is the management of keratoacanthomas?
Surgical excision
purpura, abdominal pain, and arthritis
Henoch-Schonlein Purpura - IgA mediated vasculitis triggered by infection
coin-shaped lesions that are well-demarcated, with exudates and crusting
Discoid eczema
Steroid makes a rash worse?
Think fungal causes
Deep pustular ulcer on leg which is very painful?
Think pyoderma gangrenosum
When to do wide local excision vs Mohs micrographic surgery?
Mohs used for lesions where tissue loss should be minimised e.g. face
Bullous pemphigoid has antibodies against what?
Epithelial basement membrane
Actinic keratosis is a precursor for what?
Squamous cell carcinoma
Sebhorreic keratosis is associated with what?
Gastric/Colorectal adenocarcinoma
Most common cause of erythroderma?
Skin condition such as psoriasis or eczema
Staph scalded skin vs TEN
TEN will have mucosal involvement - usually oral
What is the management of scalded skin?
IV Flucloxacillin
Withdrawal of steroids can be a trigger for what?
Psoriasis
Butterfly rash + ashleef macules + shagreen patch
Tuberous sclerosis
Management of molluscum
Watch and wait
Blistrs which cover most of the skin following an injury/graze?
Staph scalded skin
Skin prick vs patch testing?
Prick - T1 Hypersensitivity reactions
Patch - T4 Hypersensitivity
What is the most common type of BCC?
Nodular
Round/firm lesion following minor trauma?
Dermatofibroma
Hypopigmented skin on face/limbs/face with sensory loss in a traveller?
Leprosy -> treat with rifampicin, dapsone
