Important Dermatology Topics Flashcards
What are the signs and symptoms of acne rosacea?
- affects the nose, cheeks and forehead
- flushing
- telangiectasia
- persistent erythema and pustules later on
- rhinophyma (refer to dermatology)
- blepharitis
- may be exacerbated by sunlight
How do you manage rosacea?
- topical brimonidine gel (if limited telangiectasia)
- mild-moderate papules and pustules: topical ivermectin/topical metronidazole/topical azelaic acid
- moderate to severe: combination topical ivermectin + oral doxycycline
- laser therapy
- referral for rhinopehyma
What is acne vulgaris caused by?
Obstruction of pilosebaceous follicles with keratin plugs causing comedones, inflammation and pustules
Mild, moderate and severe acne vulgaris:
Mild: open and closed comedones with sparse inflammatory lesions
Moderate: widespread non-inflammatory lesions with number of papules and pustules
Severe: extensive inflammatory lesions, may include nodules, pitting and scarring
What bacteria can contribute to acne vulgaris?
Propionibacterium Acnes
How can acne vulgaris be managed?
- single topical: retinoids, benzoyl peroxide
- topical combination therapy (add antibiotic)
- oral antibiotic (max 3 months): tetracyclines, erythromycin (if pregnant)
- COCP (in combination with topical agents)
- oral isotretinoin (specialist supervision) - pregnancy contraindicated
In what cases should tetracyclines not be used to treat acne vulgaris?
pregnancy, breastfeeding or <12yo
What complication may occur as a result of acne vulgaris and how can you treat it?
Gram -ve folliculitis and treat with high dose trimethoprim
What are the 4 categories of burns?
Superficial epidermal
Partial thickness (superficial dermal)
Partial thickness (deep dermal)
Full thickness
What does a superficial epidermal burn look like?
Red and painful
What does a partial thickness (superficial dermal) burn look like?
Pale pink, painful, blistered
What does a partial thickness (deep dermal) burn look like?
White but may have patches of non-blanching erythema and reduced sensation
What does a full thickness burn look like?
White/brown/black in colour, no blisters, no pain
What is a Curling’s ulcer?
A stress ulcer that develops in the duodenum of burn patients
When should a burn be referred to secondary care?
- deep dermal and full thickness
- superficial dermal on >3% TBSA of adults and >2% in children
- involving face, hands, feet, perineum, genitalia, flexure or circumferential limbs, torso or neck
- inhalation injury
- suspicion non-accidental
Management of burns:
- superficial epidermal: symptomatic relief
- superficial dermal: cleanse, leave blister, non-adherent dressing, avoid creams
- severe burns: IV fluids if >10% TBSA in children and >15% in adults, escharotomies indicated in circumferential full thickness burns to torso or limbs (impaired ventilation otherwise)
How is the volume of IV fluids for burns calculated?
Parkland formula: TBSA x weight x 4
What is erythema nodosum?
- inflammation of subcutaneous fat
- cases tender, erythematous, nodular lesions
- usually shins
- resolves in 6 weeks
- heal without scarring
What are the causes of erythema nodosum?
- infection: streptococci, TB, brucellosis
- systemic: sarcoidosis, IBD, Behcet’s
- malignancy/infection
- drugs: penicillins, sulphonamides, COCP
- pregnancy
What is psoriasis exacerbated by?
- trauma
- alcohol
- beta blockers
- lithium
- anti-malarials
- NSAIDs
- ACEi
- infliximab
- steroid withdrawal
- strep infection and guttate psoriasis
Chronic plaque management in psoriasis:
- regular emollients
- 1st line: potent corticosteroids od with vitamin D analogue OD (one in morning and one in evening for up to 4 weeks)
- 2nd line: after 8 weeks, vitamin D analogue BD
- 3rd line: after 8-12 weeks, potent corticosteroids BD (e.g. betmethasone) or coal tar preparation
- short-acting dithranol
- phototherapy
- systemic - oral methotrexate, ciclosporin, retinoids, biologics
What are the risks of phototherapy?
- ageing
- squamous cell cancer
Scalp psoriasis management:
- potent topical corticosteroids od for 4 weeks
- different corticosteroid formulations
What are some consequences of using topical corticosteroids?
- skin atrophy
- striae
- rebound symptoms
What are vitamin D analogues and how are they used in psoriasis?
e. g. calcipotriol, calcitriol, tacalcitol
- reduced cell division and differentiation leading to reduced epidermal proliferation
- can be used long-term
- reduces scale and thickness but not erythema
- avoid in pregnancy
How does dithranol work and what are the ADRs?
inhibits DNA synthesis
wash off after 30 minutes
ADR: burning, staining
How does coal tar work in psoriasis?
inhibits DNA synthesis
What is acanthosis nigricans and how does it come about?
- symmetrical, brown, velvet plaques often on neck, axilla and groin
- insulin resistance leads to hyperinsulinaemia which causes keratinocyte and fibroblast proliferation via IGFR1
What is lichen planus, signs and symptoms and most common locations?
- itchy papular rash
- most common on palms, soles, genitalia and flexor surfaces
- white lines on surface (Wickham’s striae)
- Koebner phenomenon - lesion at site of trauma
- oral involvement 50%
- thinning nail plate and longitudinal ridging
Drug causes of lichen planus?
- gold
- quinine
- thiazides
Management of lichen planus:
- topical steroids
- benzydamine mouthwash/spray
- oral steroids or immunosuppression
What is seborrhoeic dermatitis, appearance and associations?
- chronic dermatitis due to fungus Malassezia Furfur (pityrosporum ovale)
- eczematous lesions on sebum-rich area: scalp, periorbital, auricular, nasolabial folds
- associated with HIV and Parkinson’s
Scalp treatment for seborrhoeic dermatitis:
- OTC zinc pyrithione (head and shoulders) and tar
- second line: ketoconazole
- selenium sulphide and topical corticosteroids
Face and body management for seborrhoeic dermatitis:
- topical antifungals e.g. ketoconazole
- topical steroids (short periods)
Where are venous ulcers commonly found?
Above the medial malleolus
Investigations for venous ulceration:
- ABPI normally 0.9-1.2
- <0.9 indicates arterial disease
- > 1.5 false negative due to calcification
Management of venous ulceration:
- compression bandaging (4 layers)
- oral pentoxyfylline (peripheral vasodilator)
- (flavonoids)
What is pityriasis rosea and what are the typical features?
- acute, self-limiting rash affecting young adults
- HHV7 may have role
- history of recent viral infection
- herald patch usually on trunk
- erythematous, oval, scaly patches with fir tree appearance
Differences between guttate psoriasis and pityriasis rosea?
- guttate psoriasis preceded by streptococcal sore throat 2-4 weeks
- guttate have tear drop appearance and scaly papules on trunk and limbs
- pityriasis is a herald patch followed 1-2 weeks later by multiple erythematous, slightly raised oval lesions with a fine scale and fir tree appearance
- guttate resolves spontaneously within 2-3 months
- pityriasis is self-limiting and resolves after 6 weeks
What is pityriasis versicolor?
- also known as tinea versicolor
- superficial cutaneous fungal infection by malassezia furfur
- most commonly affects trunk
- patches of hypo pigmented pink or brown
- scale
- mild pruritus
Predisposing factors for pityriasis versicolor:
- healthy individuals
- immunosuppression
- malnutrition
- Cushing’s
Management of pityriasis versicolor:
- topical anti fungal (ketoconazole shampoo)
- if not, consider alternative diagnosis
- oral itraconazole
What are actinic keratoses?
- common premalignant skin lesion due to chronic sun exposure
- small, crusty, scaly
- pink, red, brown or skin colour
- on sun-exposed areas
- multiple lesions
Management of actinic keratoses:
- prevent further exposure
- fluorouracil cream (2-3 weeks), can cause inflammation (add topical hydrocortisone)
- topical diclofenac
- topical imiquimod
- cryotherapy
- curettage and cautery
What is eczema herpeticum and how do you treat it?
- severe primary infection by HSV1 or 2
- more in children with atopic eczema
- rapidly progressing painful rash
- monomorphic, punched out erosions 1-3mm
- IV acyclovir and admit ASAP
What is dermatitis herpetiformis and how do you manage it?
- autoimmune blistering skin disorder associated with coeliac disease
- caused by deposition of IgA in dermis
- itchy, vesicular lesions on extensor surfaces
- diagnosis with skin biopsy - direct immunofluorescence
- manage with gluten free diet and dapsone
What are fungal nail infections caused by?
- onychomycosis
- caused by dermatophytes, yeasts and moulds
- RF: diabetes and age
- thickened, rough, opaque
- investigate with nail clippings (false negative in 30%
Management of fungal nail infections:
- dermatophytes - oral terbinafine, oral itraconazole
- 6 weeks - 3 months for fingernails
- 3-6 months for toenails
- candida - mild topical antifungals - oral itraconazole
- 6 months fingernails
- 9-12 months toenails
What is pyoderma gangrenosum?
- affecting the lower limbs usually
- starts as small red papule and develops into deep, red, necrotic ulcers with violaceous borders
- may cause systemic symptoms e.g. fever, myalgia
What are the causes of pyoderma gangrenosum?
- idiopathic (50%)
- IBD
- RA
- SLE
- myeloproliferative
- lymphoma
- myeloid leukaemia
- monoclonal gammopathy (IgA)
- primary biliary cirrhosis
Management of pyoderma gangrenosum:
- oral steroids
- ciclosporin and infliximab
What is scabies caused by and what are the symptoms?
- mite - Sarcoptes Scabiei
- spread by prolonged skin contact in children and young adults
- lays eggs in stratum corneum
- intense pruritus caused by delayed T4 hypersensitivity for 30 days
- linear burrows on side of fingers, interdigital webs, flexor surfaces e.g. wrist
- also affects face and scalp in infants
- excoriation and infection
Management of scabies:
- permethrin 5%
- malathion 0.5%
- pruritus 4-6 weeks post-eradication common
- avoid close contact until treatment complete
- treat all contacts and laundry
What is Norwegian scabies?
- crusted scabies
- suppressed immunity e.g. HIV
- ivermectin and isolation
What is shingles and the risk factors + symptoms:
- acute, unilateral, painful blistering rash caused by reactivation of VZV
- RF: increasing age, HIV, immunosuppressed
- most commonly T1-L2
- burning pain for 2-3 days, severe fever, headache, lethargy
- rash initially erythematous, macular rash becoming vesicular
- does not cross mid-line of dermatome but some bleeding into adjacent areas
Diagnosis and management of shingles:
- clinical diagnosis
- paracetamol and NSAIDs
- amitriptyline (or other neuropathic agents)
- oral corticosteroids if immunocompetent
- antivirals within 72 hours (unless <50yo and mild truncal rash with mild pain and no underlying risk factors) - reduced incidence post hepatic neuralgia
- aciclovir, famciclovir, valaciclovir
Complications of shingles:
- post-herpetic neuralgia
- herpes zoster ophthalmic (ocular division of trigeminal nerve)
- herpes zoster oticus (Ramsay Hunt Syndrome)
- may result in ear lesions and facial paralysis
What are the possible rashes occurring in pregnancy:
- atopic eruption of pregnancy
- polymorphic eruption of pregnancy
- pemphigoid gestationis
What is atopic eruption of pregnancy?
- most common skin disorder in pregnancy
- eczematous, itchy red rash
- no treatment needed
What is polymorphic eruption of pregnancy and how do you treat it?
- pruritic condition in last trimester
- lesions first in abdominal striae
- use emollients, mild potency topical steroids and oral steroids
What is pemphigoid gestationis and how do you treat it?
- pruritic blistering lesions
- often peri-umbilical region to trunk, back, buttocks and arms
- second and third trimester
- treat with oral corticosteroids
What are the risk factors for squamous cell carcinoma of the skin?
- excessive sun exposure
- actinic keratoses and Bowen’s disease
- immunosuppression e.g. following renal transplant, HIV
- smoking
- Marjolin’s ulcer
- genetic: xeroderma pigmentosum, oculocutaneous albinism
Management of squamous cell carcinoma:
- surgical excision with 4mm margins if <20mm diameter
- 6mm if >20mm diameter
What are signs of good prognosis with squamous cell cancer?
- well differentiated tumours
- <20mm diameter
- <2mm deep
- no associated diseases
What are signs of poor prognosis with squamous cell carcinoma?
- poorly differentiated
- > 20mm diameter
- > 4mm deep
- immunosuppression
What is erythema multiforme?
- hypersensitivity reaction mostly triggered by infections
- causes target lesions initially on back of hands/feet and moving to torso, upper limbs (more than lower) and sometimes mild pruritus
What are the causes of erythema multiforme?
- viruses (herpes)
- idiopathic
- mycoplasma
- strep
- drugs: penicillin, sulphonamides, carbamazepine, allopurinol, NSAIDs, COCP
- CTD: SLE, sarcoidosis, malignancy
What is erythema multiforme major?
- most severe form
- mucosal involvement
What is hereditary haemorrhagic telangiectasia and the 4 diagnostic criteria?
- Osler-Weber-Rendu syndrome
- autosomal dominant
4 diagnostic criteria:
- epistaxis - spontaneous, recurrent
- telangiectasia
- visceral lesions: e.g. GI, pulmonary AV malformations, hepatic AVM, cerebral, spinal
- FHx: 1st degree relative
Types of malignant melanoma:
- superficial spreading
- nodular
- lentigo maligna
- acral lentiginous
What is superficial spreading malignant melanoma?
- 70% cases
- arms, legs, back and chest
- young people
- growing moles
What is nodular malignant melanoma?
- most aggressive
- second most common
- sun exposed skin
- middle aged people
- red/black lump or easily bleeds/oozes
What is lentigo maligna malignant melanoma?
- less common
- chronically sun-exposed skin
- older people
- growing mole
What is acral lentiginous malignant melanoma?
- rare form
- nails, palms or soles
- African Americans or Asians
- subungual pigmentation (Hutchinson’s sign) or on palms or feet
Main diagnostic features (major criteria) for malignant melanoma:
- change in size
- change in shape
- change in colour
Secondary features (minor criteria) for malignant melanoma:
- diameter >=7mm
- inflammation
- oozing or bleeding
- altered sensation
Margins of excision related to Breslow thickness for malignant melanoma:
- 0-1mm thick: 1cm
- 1-2mm thick: 1-2cm
- 2-4mm thick: 2-3cm
- > 4mm thick: 3cm
What is toxic epidermal necrolysis?
- potentially life-threatening secondary to drug reaction
- scalded appearance
- systemically unwell - pyrexia and tachycardia
- positive Nikolsky’s signs - epidermis separates with mild lateral pressure
Drugs causing toxic epidermal necrolysis:
- phenytoin
- sulphonamides
- allopurinol
- penicillins
- carbamazepine
- NSAIDs
Management of toxic epidermal necrolysis:
- supportive care (electrolyte derangement and volume loss)
- ciclosporin, cyclophosphamide, plasmapheresis
What is vitiligo?
- autoimmune loss of melanocytes - depigmentation of skin
- 20-30yo
- well-demarcated patches of depigmentation, mostly peripheral
- Koebner phenomenon
What conditions are associated with vitiligo?
- T1DM
- Addison’s
- autoimmune thyroid
- pernicious anaemia
- alopecia areata
Management of vitiligo:
- sunblock
- topical corticosteroids
- topical tacrolimus
- phototherapy
Basal cell carcinomas and management:
- rodent ulcers - slow growth and local invasion
- metastases rare
- sun-exposed areas
- pearly, flesh-coloured papules and telangiectasia with central craters
- surgical removal, curettage, cryotherapy, imiquimod, fluorouracil, radiotherapy
What is hirsutism?
androgen-dependent hair growth in women
What are the causes of hirsutism?
- PCOS (most common)
- Cushing’s
- congenital adrenal hyperplasia
- androgen therapy
- obesity
- adrenal tumour
- androgen secreting ovarian tumour
- phenytoin
- corticosteroids
What assessment is used for hirsutism?
Ferriman-Gallway
What is the management for hirsutism?
- weight loss
- COCP
- facial - topical eflornithine
What are the causes of androgen-independent hypertrichosis?
- minoxidil, ciclosporin, diazoxide
- congenital hypertrichosis lanuginosa, congenital hypertrichosis terminalis
- porphyria cutanea tarda
- anorexia nervosa
What is impetigo?
- superficial bacterial skin condition caused by staph aureus or strep pyogenes
- primary infection or complication of eczema, scabies or insect bites
- common in children and warm weather
- spread by direct contact
- very contagious
What is the incubation of impetigo?
4-10 days
What is the management of impetigo and exclusion rules?
- limited/localised: hydrogen peroxide cream, topical fusidic acid, mupicorin
- extensive: oral flucloxacillin, erythromycin
- exclude until lesions crusted and healed or 48 hours after starting Abx
What is lichen sclerosus?
- inflammatory condition affecting genitalia and common in elderly females
- atrophy of epidermis
- white plaques
- prominent itch
- diagnosis clinical or biopsy
What are you at increased risk of with lichen sclerosus and the management?
- vulval cancer
- topical steroids and emollients
What is molluscum contagiosum?
- poxviridae
- transmission by direct personal contact or via contaminated surfaces
- mostly children
- characteristic pink or pearly white papules with central umbilication up to 5mm
- self-limiting (spontaneous resolution in 18 months)
Where does molluscum contagiosum appear?
- children: trunk, flexures, anogenital
- adults: genitalia, pubis, thighs, abdo
Management of molluscum contagiosum:
- not recommended
- squeezing, cryotherapy
- emollients or mild topical corticosteroids for itching
- appears infected - topical antibiotics
- HIV or ocular lesions - refer to specialist
What are seborrhoeic keratoses and how do you treat?
- benign epidermal lesions in older people
- may have keratitis plugs
- curettage, cryosurgery and shave biopsy
What is alopecia areata?
- autoimmune condition
- localised, well-demarcated patches of hair loss
- broken exclamation mark hairs at edge
- regrows in 1 year for 50% and 80-90% eventually
Management of alopecia areata:
- topical/intralesional corticosteroids
- topical minoxidil
- phototherapy
- dithranol
- contact immunotherapy
- wigs
What is bullous pemphigoid, how do you investigate?
- autoimmune sub-epidermal blistering condition
- secondary to development of antibodies against hemidesmosomal proteins BP180 and BP230
- itchy, tense blisters around flexures which heal without scarring
- usually no mucosal involvement
- skin biopsy with immunofluorescence showing IgG and C3 at dermoepidermal junction
In whom is bullous pemphigoid more common?
elderly
Management of bullous pemphigoid?
- refer to dermatology
- oral corticosteroids
- topical corticosteroids
- immunosuppressants and antibiotics
What is erysipelas and management?
- localised skin infection caused by streptococcus pyogenes
- more superficial, limited version of cellulitis
- flucloxacillin
What is guttate psoriasis?
- more common in children and adolescents
- precipitated by streptococcal infection 2-4 weeks before lesions
- teardrop papules on trunk and limbs
- resolves spontaneously in 2-3 months
- no antibiotics needed
- topical agents as per psoriasis
- tonsillectomy to prevent recurrence
What are keloid scars?
tumour-like lesions from connective tissue of scar which extend beyond original margins
Predisposing factors for keloid scar:
- ethnicity
- young adults
- sternum
- shoulder
- neck
- face
- extensor surfaces
- trunk
Management of keloid scars:
- less likely if incisions made along relaxed skin tension lines
- early treated with intra-lesional steroids e.g. triamcinolone
- sometimes excision
What is Koebner phenomenon?
- lesions appearing at site of injury
- psoriasis, vitiligo, warts, lichen planus, lichen sclerosus, molluscum contagiosum
Causes of pruritus:
- liver disease
- iron deficiency
- polycythaemia
- CKD
- lymphoma
- hypo/hyperthyroidism
- diabetes
- pregnancy
- senile pruritus
- urticaria
- skin disorders: eczema, scabies, psoriasis, pityriasis rosacea
What are salmon patches?
- vascular birthmark
- pink and blotchy
- forehead, eyelids, nape of neck
- fade over few months
What is Kaposi sarcoma?
- tumour of vascular and lymphatic endothelium
- purple cutaneous nodules
- associated with immunosuppression - aggressive
- affects elderly females
- growing
