Dermatology Flashcards
What is a macule?
Flat, non-palpable change in skin colour, <0.5cm diameter
What is a patch?
Flat, non-palpable change in skin colour, >0.5cm diameter
What is a vesicle?
Fluid within upper layers of skin, <0.5cm diameter
What is a blister?
Fluid within upper layers of skin, >0.5cm diameter
What is a bulla?
Large fluid-filled lesion below epidermis, >10cm diameter
What is a pustule?
Visible collection of pus in subcutis
What is a nodule?
Mass or lump >0.5cm diameter
What is a callus?
Hyperplastic epidermis, often found on the soles,
palms + other areas of excessive use
What is a plaque?
Raised area >2cm diameter
What is a wheal?
Dermal oedema
What is a fissure?
Linear crack
What is an ulcer?
Full thickness skin loss
What is an excoriation?
Scratch mark
What is lichenification?
Thickening of epidermis with exaggerated skin marking usually due to repeated scratching
What are telangiectasia?
Easily visible superficial blood vessels
What is purpura?
Rash caused by blood in skin
What is petechia?
Micro-haemorrhage, 1-2mm diameter
What are some examples of hypopigmented or depigmented lesions?
Vitiligo
Pityriasis versicolor
Pityriasis alba
What are some examples of hyperpigmented lesions?
Lentigos Café-au-lait spots Melasma (chloasma) Melanocytic naevi Seborrhoeic keratoses Systemic diseases: Addison’s, haemochromatosis
What are some examples of ring shaped lesions?
BCC
Tinea (ringworm)
Granuloma annulare
Erythema multiforme
What are some examples of round/discoid lesions?
Bowen’s disease Discoid eczema Psoriasis Pityriasis rosea Erythema migrans Impetigo
What are some examples of linear lesions?
Kobner phenomenon: lesions related to skin injury
Dermatitis artefacta: lesions induced by pt
Herpes zoster
Scabies burrows
What dermatological conditions cause itchy lesions?
Scabies, urticaria, atopic eczema, dermatitis herpetiformis, lichen planus
What systemic diseases are associated with itchy lesions?
Iron def., lymphoma, hypo/hyperthyroidism, liver disease, CKD, polycythaemia, drugs (statins, ACEi, opiates)
How should vitiligo be managed?
Sun protection, cosmetic camo, topical steroids may induce repigmentation, phototherapy
What is pityriasis versicolor?
Superficial slightly scaly yeast infection
Appears hypopigmented on darker skin
What is pityriasis alba?
Post-eczema hypopigmentation, often on child’s face
What are lentigos?
Brown macules/patches that persist in winter, unlike freckles
Describe the appearance of seborrhoeic keratoses:
Benign greasy-brown warty lesions usually on back,
chest and face
Stuck on appearance
What are actinic (solar) keratoses?
Pre-malignant crumbly yellow-white scaly crusts on sun-exposed skin
What are some management options for actinic keratoses?
Observation
Topical 5-FU, imiquimod or diclofenac
Cryotherapy, photodynamic therapy
Surgical excision and curettage
What is Bowen’s disease?
Well-defined slowly enlarging red scaly plaque with flat edge
3-5% progress to SCC
What are some management options for Bowen’s disease?
Cryo, topical 5-FU or imiquimod,
photodynamic, curettage, excision
What is keratoacanthoma?
Smooth dome-shaped papule, rapidly grows to become a crater centrally
What is the management for keratoacanthoma?
Urgent excision
Describe the appearance of squamous cell carcinoma:
Persistently ulcerated or crusted firm irregular lesion often on sun-exposed sites
What factors increase the risk of metastasis in squamous cell carcinoma?
If on lip, ear or non-sun exposed site
>2cm
Poor differentiation
Immunosuppression
What is the management for squamous cell carcinoma?
Local complete excision with 4-6mm margin
Describe the appearance of nodular basal cell carcinoma:
Pearly nodule with rolled telangiectatic edge on face or sun-exposed site
Describe the appearance of superficial basal cell carcinoma:
Red, scaly plaques with raised smooth edge, often on trunk or shoulders
How should basal cell carcinoma be managed?
Excision
Can use cryo, curettage, RT, photodynamic, topical if superficial at low risk site
What cancers may metastasise to the skin?
Breast, stomach + colon, lung, genitourinary
What is leukoplakia? Who is it more common in?
Premalignant condition, white hard spots on mucous membrane of mouth
More common in smokers
What is mycosis fungoides?
Cutaneous T-cell lymphoma
Well-defined itchy red scaly plaques progressing to red-brown infiltrated plaques and ulcerating tumours
What is Fitzpatrick skin type I?
Pale white skin, blonde/red hair
Always burns, does not tan
What is Fitzpatrick skin type II?
Fair skin, blue eyes
Burns easily, tans poorly
What is Fitzpatrick skin type III?
Darker white skin
Tans after initial burn
What is Fitzpatrick skin type IV?
Light brown skin
Burns minimally, tans easily
What is Fitzpatrick skin type V?
Brown skin
Rarely burns, tans darkly easily
What is Fitzpatrick skin type VI?
Dark brown or black skin
Never burns, always tans darkly
What are some risk factors for malignant melanoma?
UV exposure, sunburn, fair complexion, >50 melanocytic or dysplastic naevi, FH, previous melanoma, age
What are some signs of malignant melanoma (ABCDEF)?
Asymmetry in outline of lesion Border irregularity Colour variation Diameter >6mm Evolution (size, elevation, colour) Funny looking mole, different from others/mole signature
What are the types of malignant melanoma?
Superficial spreading (70%)
Nodular (15%)
Acral lentiginous (10%)
Lentigo maligna melanoma (5%)
How should malignant melanoma be managed?
Excision biopsy with 2mm margin allowing for histological diagnosis and Breslow thickness
If MM confirmed, wider excision (up to 3cm) to
ensure complete removal and may do SNLB
How should metastatic melanoma be managed?
Palliation: chemo, biological, novel targeting therapy and ipilimumab
What is psoriasis?
Chronic inflammatory skin condition characterised by scaly erythematous plaques, typically relapsing remitting course
What are some triggers for psoriasis?
Stress, infections, skin trauma (Kobner), drugs (lithium, NSAIDs, beta blockers), withdrawal of systemic steroids
What are the types of psoriasis?
Chronic plaque Flexural Guttate Pustular Generalised
Describe chronic plaque psoriasis:
Symmetrical well-defined red plaques with silvery scale on extensor aspects, scalp and sacrum
Describe guttate psoriasis:
Large numbers of small plaques <1cm (teardrop) over trunk and limbs, seen in young (esp. after acute strep infection), lasting 3-4m
What nail changes are associated with psoriaisis?
Pitting, onycholysis (separation from nail bed),
thickening, subungal hyperkeratosis
How should psoriatic arthropathy treated?
NSAIDs, DMARDs, anti-TNF
What are the management options for psoriasis?
Emollients
Topical corticosteroid and topical vit D
Phototherapy or systemic therapy if not controlled or if >10% body area affected
What are the side effects of phototherapy?
Increased risk of SCC, sunburn, dry skin, folliculitis, cold sores, polymorphic light eruption
What non-biologic oral drugs may be used in the management of psoriasis?
Methotrexate
Ciclosporin
Acitretin
Dimethyl fumarate and apremilast
What biologics may be used in the management of psoriasis and what is the MoA?
Inhibit T cell activation and function or neutralise cytokines
Infliximab, adalimumab, etanercept (anti-TNF), ustekinumab (interleukin inhibitor)
What are the diagnostic criteria for atopic eczema?
Child must have itchy skin with 3+ of:
- Onset before 2y
- Past flexural involvement
- History of generally dry skin
- Personal history of other atopy
- Visible flexural dermatitis or on cheeks/forehead if <4y
What are the management options for atopic eczema?
Emollients: use liberally (3-4x/day)
Topical steroids for exacerbations
Treat secondary bacterial infection with oral Abx
Topical tacrolimus if not controlled
Azathioprine, ciclosporin or methotrexate if uncontrolled severe disease
Describe adult seborrheic dermatitis:
Overgrowth of skin yeasts causes red, scaly rash affecting scalp (dandruff), eyebrows, nasolabial folds, cheeks and flexures
How should adult seborrheic dermatitis be managed?
Scalp: OTC preps containing zinc pyrithione (Head + Shoulders)
Body: mild topical steroid/antifungal prep e.g. Daktacort or ketoconazole
What can cause irritant dermatitis?
Detergents, soaps, oils, solvents, alkalis
How should irritant dermatitis be managed?
Avoiding irritants, hand care with soap substitutes, emollients, careful drying and gloves
What can cause allergic contact dermatitis?
Nickel (jewellery, watches), chromates (leather), lanolin, rubber, plants
How can allergic contact dermatitis be managed?
Patch testing and avoidance of allergen, use topical
steroid based on severity
What is an example of a mild topical steroid?
Hydrocortisone
What is an example of a moderate topical steroid?
Eumovate (Clobetasone)
What is an example of a potent steroid?
Betnovate (Betamethasone)
What is an example of a very potent steroid?
Dermovate (Clobetasol)
What are some side effects of topical steroids?
Skin thinning, irreversible striae, telangiectasia, worsening of untreated infection, contact dermatitis
Approximately what area is covered by one fingertip unit of topical steroid?
Palmar surface of 2 adult hands
What is the pathophysiology of acne vulgaris?
Basal keratinocyte proliferation in pilosebaceous follicles, ↑sebum production, Propionibacterium acnes colonisation, inflammation, comedones blocking secretions hence papules, nodules, cysts and scars
Describe mild acne:
Mainly facial comedones
What is the management for mild acne?
Topical BPO, topical retinoid e.g. isotretinoin or topical Abx alone
Describe moderate acne:
Inflammatory lesions (papules and pustules)
What is the management for moderate acne?
Topical BPO combined with Abx or topical retinoid (Epiduo)
Then lymecycline or erythromycin (pregnant or <12y), use for 3m with topical BPO
Describe severe acne:
Nodules, cysts, scars and inflammatory papules or pustules
What is the management for severe acne?
Oral isotretinoin
What is rosacea?
Chronic relapsing/remitting disorder of BVs and
pilosebaceous units in central facial areas
What can trigger rosacea?
Stress/blushing, alcohol and spices
What are some signs of rosacea?
Central facial rash with erythema, telangiectasia,
papules, pustules, inflammatory nodules
How should rosacea be managed (include mild + severe)?
Soap substitutes, avoid sun over-exposure, use sun-block
Mild: topical metronidazole or topical 15% azelaic acid gel
Moderate or severe: oral tetracycline for 4m
Describe morbilliform drug eruption:
Generalised erythematous macules + papules often on trunk within 1-3w of drug exposure
Describe urticaria drug reaction:
Itchy erythematous wheals appear rapidly after drug exposure ± angioedema/anaphylaxis
Describe erythroderma (exfoliative dermatitis):
Widespread erythema and dermatitis affecting >90% body surface
Describe Stevens-Johnson syndrome:
Painful erythematous macules evolving to form target lesions, severe mucosal ulceration of 2+ surfaces e.g.
conjunctiva, oral cavity, labia, urethra
Describe toxic epidermal necrolysis:
Widespread painful dusky erythema then necrosis of
epidermis with mucosa severely affected
What are some examples of drugs that can cause drug eruptions?
Sulphonamides, anti-epileptics, penicillins, NSAIDs, cephalosporins, allopurinol
What skin signs can diabetes cause?
Flexural candidiasis, acanthosis nigricans, granuloma annulare, folliculitis
What skin signs can lupus cause?
Facial butterfly rash, photosensitivity, diffuse alopecia, discoid lupus, livedo reticularis
What skin signs can IBD cause?
Erythema nodosum, pyoderma gangrenosum
How does erythema multiforme present?
Well defined target lesions on extensor surfaces of
peripheries
What can cause erythema multiforme?
Herpes simplex (70%), mycoplasma, CMV, drugs.
Describe erythema migrans:
Papule becomes spreading red ring lasting weeks to months (pathognomonic of Lyme disease)
Describe livedo reticularis:
Non-blanching vague pink-blue mottling caused by capillary dilatation and stasis in skin venules, most often in legs
Describe ringworm infection:
Round, scaly, itchy lesion with inflammed edge compared to centre
How should ringworm infection be investigated?
Sending skin scrapings from active edge, scalp brushings or nail clippings for microscopy and culture
How should ringworm infection be managed (include management for nail infection)?
Topical antifungal creams (terbinafine or imidazole) for 2w
If nail: oral terbinafine
What is the management for candida?
Imidazole creams
What is the management for pityriaisis versicolor?
Imidazole creams, ketoconazole shampoo
What is onychomycosis?
Thickened, rough, opaque nails
Mainly due to Trichophyton rubrum
When and how should onychomycosis be treated?
Only treat if symptomatic and use oral terbinafine for months
What is impetigo?
Contagious superficial infection caused by S. aureus Lesions usually start around nose and face with honey coloured crusts on erythematous base
How should impetigo be treated?
Hydrogen peroxide, topical fusidic acid or flucloxacillin if severe
What is erysipelas?
Sharply defined superficial infection caused by S. pyogenes
What are some signs of cellulitis?
Pain, swelling, erythema, systemic upset, lymphadenopathy
How should cellulitis be managed?
Benpen IV + fluclox PO
What is the cause of warts?
HPV in keratinocytes
How should common warts be managed?
If painful or persisting can use topical salicylic acid, cryotherapy, duct tape occlusion
How should genital warts be managed?
Observe, podophyllin/imiquimod cream, cryotherapy
Describe the appearance of molluscum contagiosum:
Pink papules with umbilicated central punctum
What is the cause of molluscum contagiosum?
Pox virus
Describe herpes simplex infection:
Grouped painful vesicles on erythematous base
When should shingles be treated with oral acyclovir?
If >50y, ophthalmic, severe, immunosuppressed
What are some complications of herpes zoster infection?
Post-herpetic neuralgia, meningitis, encephalitis
Describe the appearance of lichen planus:
Lesions are purple, pruritic, poly-angular, planar, papules
Can have white lines on surface (Wickham’s striae). Often on flexor aspects of wrists, forearms, ankle and legs
How should lichen planus be managed?
Topical steroids
Describe the appearance of pyogenic granuloma:
Fleshy moist red lesion which grows rapidly and bleeds easily
How should pyogenic granuloma be managed?
Curettage
Describe the appearance of pityriasis rosea:
Self-limiting rash preceded by herald patch (oval red scaly patch)
Describe alopecia areata:
Smooth well-defined round patches of hair loss on
scalp, exclamation mark hairs
What can cause scarring alopecia?
Lichen planus, discoid lupus, trauma, BCC, SCC
What is the cause of bullous pemphigoid and how does it present?
IgG autoantibodies to BM
Tense blisters on inflammed or normal skin
How should bullous pemphigoid be managed?
Very potent steroids (clobetasol), oral pred
What is the cause of pemphigus vulgaris and how does it present?
IgG autoantibodies against desmosomal components which leads to acantholysis (keratinocytes separate from each other)
Mucosal ulceration, skin blistering
How should pemphigus vulgaris be managed?
Treat with pred
Rituximab + IV Ig (if resistant)
What is eczema herpeticum?
Severe primary infection often by HSV1/2
More common in children with atopic eczema
How does eczema herpeticum present?
Rapidly progressing painful rash, monomorphic punched out erosions
How should eczema herpeticum be managed?
Admit for IV acyclovir
What can cause chondrodermatitis nodularis helicis?
Persistent pressure (sleep), trauma or cold
How should chondrodermatitis nodularis helicis be managed?
Use ear protectors during sleep, cryo, steroid infection, collagen injection
What is dermatitis herpetiformis?
Autoimmune blistering skin disorder associated with
coealic, deposition of IgA in dermis
How does dermatitis herpetiformis present?
Itchy, vesicular skin lesions on extensor surfaces and buttocks
How should dermatitis herpetiformis be managed?
Gluten free diet and dapsone
What is erythema ab igne?
Reticulated, erythematous patches with hyperpigmentation and telangiectasia due to exposure to infrared radiation
What is erythema nodosum?
Inflamm of subcut fat causes tender, erythematous, nodular lesions
Usually occurs over shins
What are some causes of erythema nodosum?
Infection (strep, TB), sarcoid, IBD, malignancy, pregnancy
Describe the appearance of pyoderma gangrenosum:
Small red papule -> deep, red, necrotic ulcer with violaceous border
What are some causes of pyoderma gangrenosum?
Idiopathic (50%), IBD, RA, SLE, malignancy
What is the cause of staphylococcal scalded skin syndrome?
Release of exotoxins by S. aureus
How should staphylococcal scalded skin syndrome be managed?
IV Abx
What are some common causes of skin ulcers?
Neuropathy
Vascular – venous (75%), arterial (10%), mixed (15%)
Trauma
What are some risk factors for venous ulcers?
Varicose veins, DVT, venous insufficiency, poor calf muscle function, AV fistula, obesity, leg fracture
How should venous ulcers be treated and what investigations must be performed before treatment?
Compression bandaging and occlusive dressings
Dopplers and ABPI to exclude arterial disease
What are some risk factors for pressure ulcers?
Extremes of age, reduced mobility and sensation, vascular disease, chronic/terminal illness
What are the 4 stages of pressure ulcers?
Stage I: non-blanching erythema over intact skin
Stage II: partial thickness skin loss
Stage III: full thickness skin loss, extending into fat
Stage IV: destruction of muscle, bone or tendon
How should pressure ulcers be managed?
Pressure-relieving mattress and cushions, freq repositioning, modern dressing, debride dead tissue, negative pressure treatment
How can pressure ulcers be prevented?
Initial and ongoing assessment, regular inspection of skin, minimise excess moisture, regular turning
What is the cause of Kaposi’s sarcoma?
HHV-8
How does Kaposi’s sarcoma present?
Purple patches or plaques on skin and mucosa of any organ
What is the treatment for Kaposi’s sarcoma?
HAART, systemic interferon alfa or chemo, excision
What are some signs of scabies infestation?
Very itchy papules, vesicles, pustules and nodules affecting finger webs, wrist flexures, axilla, abdo, buttocks and groins
How should scabies be managed?
Treat all members of household and close contacts with permethrin 5% cream
How should headlice be managed?
Malathion, dimeticone
Fine-toothed comb to remove lice and nits
What is a papule?
Raised area <0.5cm diameter
What are some side effects of oral isotretinoin?
Teratogen, skin and mucosal dryness, depression