Dermatology Flashcards
How to examine a skin lesion
Inspect - site, number of lesions, distribution and configuration
Describe - size, shape, colour, secondary changes, morphology, margin
If pigmented: Asymmetry, irregular Border, two or more Colours, >7mm Diameter
Palpate - consistency, mobility, tenderness, temperature
Systemic check - nails, scalp, hair + mucous membranes
What is a lesion?
Area of altered skin
Definition of a rash
An eruption
Definition of a naevus
Localised malformation of tissue structures
Definition of a comedone
Plug in sebaceous follicle containing sebum, bacteria and cellular debris
Open = blackheads
Closed = whiteheads
Definition of generalised
All over body
Definition of widespread
Extensive
Definition of localised
One area of skin only
Pressure areas
Sacrum, buttocks, ankles, heels
Photosensitive
Affects sun-exposed areas such as face, neck and back of hands
What is distribution?
Pattern of spread of lesions:
Generalised, widespread, localised?
Flexor/ extensor/ pressure areas/ dermatomes/ photosensitive area?
What is configuration?
Pattern or shape of grouped lesions:
Discrete, confluent, linear, target, annular, discoid
Definition of discrete
Individual lesions separated from each other
Definition of confluent
Merging together
Definition of linear
In a line
Definition of target
Concentric rings (bullseye)
Definition of annular
Rings
Definition of discoid
Coin shaped/ round
Types of colour of a lesion
Erythema/ purpura
Hypo/ hyper/ depigmented
Definition of erythema
Redness which blanches
Definition of purpura
Red or purple that does not blanch
Definition of petechiae
Purpura - small pinpoint macules
Definition of ecchymoses
Purpura - large bruise like patches
Hypo/ hyper/ depigmented
Hypo = paler skin Hyper = darker skin De = white skin due to absence of melanin
Definition of morphology
Structure of lesion
Definition of macule
Flat area of altered colour (freckle)
Definition of patch
Large flat area of altered colour
Definition of papule
Solid raised lesion <0.5cm (xanthomata)
Definition of nodule
Solid raised lesion >0.5cm
Definition of plaque
Palpable scaling raised lesion >0.5cm (psoriasis)
Definition of vesicle
Raised, clear fluid filled lesion <0.5cm (acute hand eczema)
Definition of bulla
Raised, clear fluid filled lesion >0.5cm (reaction to insect bites)
Definition of pustule
Pus containing lesion <0.5cm (acne)
Definition of abscess
Localised accumulation of pus in dermis
Definition of weal
Transient raised lesion due to dermal oedema (urticaria)
Definition of boil/ furuncle
Staph infection around or within hair follicle
Definition of carbuncle
Staph infection of adjacent hair follicles (multiple boils)
Definition of secondary lesions
Excoriation, scales, crust, scar, ulcer, fissure, striae
Definition of excoriation
Loss of epidermis following trauma
Definition of scales
Excoriations in eczema (psoriasis showing silvery scales)
Definition of crust
Rough surface made of serum, blood, bacteria and debris
Exuded through eroded epidermis
eg impetigo
Definition of a scar
New fibrous tissue post wound healing
Atrophic = thinning
Hypertrophic = hyperproliferation within would boundary
Keloidal = hyperproliferation beyond wound boundary
Definition of an ulcer
Loss of epidermis and dermis
Definition of a fissure
Epidermal crack due to excess dryness
Definition of striae
Linear areas going from purple > pink > white
Due to steroid use or growth spurts
Definition of hirsutism
Androgen dependant hair growth in a female
Definition of hypertrichosis
Non androgen dependant hair growth
Definition of koilonychia
Spoon shaped depression of nail due to anaemia
Definition of onycholysis
Separation of distal end of nail from nail bed
Due to psoriasis or hyperthyroidism
Definition of pitting
Punctate depressions of nail due to psoriasis and eczema
Psoriasis presentation
Raised area of red skin covered in silvery scales (plaques). Found on extensor surfaces + scalp, usually widespread confluent lesions. Itchy and painful
Pathophysiology of psoriasis
New cells move up skin layers to outermost level in 2-6 days - not fully mature cells build up causing red, flaky scales
What is guttate psoriasis?
In young children and adults
Small pink patches without scaling
Develops after strep throat
Treatment for psoriasis
Phototherapy Medications: 1) Acitretin (retinoid) - not for women of child bearing age 2) Ciclosporin 3) Methotrexate 4) Hydroxycarbamide
Atopic eczema presentation
Itchy erythematous dry scaly patches on face and extensor aspects in infants, and flexor aspects in children and adults
Acute lesions are exudative papules and vesicles on erythematous base
Chronic scratching can cause excoriations
May have nail pitting
Eczema management
Emollients
Topical steroids for flare ups
Oral abx for secondary bacterial infections
Oral steroids for severe resistant cases
Eczema complications
Secondary bacterial infections
Molluscum contagiosum
Viral warts
Eczema herpeticum
Presentation of acne
Open and closed comedones
Papules, pustules and nodules
Complications of acne
Hyperpigmentation
Scarring
Deformity
Basal cell carcinoma presentation
Nodular is most common
Small, skin coloured papule or nodule with surface telangiectasia + pearly rolled edge
Lesion may have necrotic or ulcerated centre
Usually over head or neck
Squamous cell carcinoma presentation
Keratotic (scaly, crusty) ill defined nodule, may ulcerate
Malignant melanoma presentation
Asymmetrical, irregular border, irregular colour, large diameter, changing in size or shape
Common on legs and trunk
May itch or bleed
What is erythema nodosum + what are the causes?
Inflammation of SC fat
Causes tender, red nodular lesions over shins/ forearms
Due to strep/ IBD/ sarcoidosis/ penicillins/ COCP
Treatment for actinic keratosis
Fluoruracil cream or imiquimod cream
Treatment for lupus
NSAIDs
Corticosteroids
Hydroxychloroquine (especially for the rash)
Erysipelas presentation and treatment
Sharply demarcated raised edge rash
Treat with penicillin/ erythromycin
Treatment for impetigo
Fusidic acid or mupirocin
Treatment for shingles
Oral acyclovir
What is atopic dermatitis?
Hypersensitivity to allergens
Form of eczema Infants: face + nappy area
Children: flexures, neck + Dennie-Morgan folds
Adults: flexures + hands
Treatment of atopic dermatitis
Emollients, steroids, immunomodulatory therapy
What is seborrhoeic dermatitis?
Rash appears in sebaceous glands ie scalp, sides of nose, behind ears
Cradle cap in infants (starts at 2-6 months)
Thick, yellow, waxy scales
Treatment for seborrhoeic dermatitis
Adult = medicated shampoo
Infants = emollients
What is stasis dermatitis?
AKA Varicose eczema
Common in later life
Vein walls weakened, blood pools in legs forming red-brown speckles on skin which are hot and itchy
RF for stasis dermatitis?
Poor circulation, DVTs, cellulitis, varicose veins, phlebitis, obesity
Treatment for stasis dermatitis?
Lose weight, treat varicose veins, compression stockings, emollients, topical steroids
What is asteatoic dermatitis?
Eczema cracquelee
Over 60s
Appears on shins with ‘crazy paving’ appearance
Treat with emollients + steroids
What is contact dermatitis?
Result of contact with irritants or allergens
Common on hands + face
Histological findings of psoriasis
Thick epidermis (acanthosis) with saw tooth appearance
Papillary dermis close to surface
Vascular proliferation (Auspitz’s sign)
How do you assess psoriasis?
Psoriasis Area and Severity index (PASI)
Dermatology Life Quality Index (DLQI)
Advise for pts with acne
Avoid over-cleaning
Use non-comedogenic makeup
Avoid picking or squeezing
Acne treatments take 8 weeks to work
Management of mild acne with open + closed comedones
Single topical treatment eg retinoid (adapalene) or benzoyl peroxide
Azelaic acid 2nd line
Management of moderate acne with inflammatory lesions
Add oral abx (lyme/doxycycline)
When should isotretinoin be considered for acne?
Non-response to 2 courses of abx or scarring
Pathology + S+S of warts
Small rough growths caused by HPV
Usually on hands + feet
What is a verruca?
Plantar wart (on sole of foot)
Types of warts
Common = firm + raised with rough surface, resembles cauliflower Plane = round, flat topped + yellow, commonly on hands Filiform = long + slender, commonly face + neck Plantar = soles of feet Mosaic = palmar or plantar warts coalesce into larger plaques
Management of warts
Watch + wait if asymptomatic
Salicylic acid, cryotherapy or combo
In secondary care: physical ablation, topical podophyllotoxin, virucidal tx
Types of pigmented lesion
Melanoma Moles (naevi) Seborrhoic keratoses Freckles Dermatofibromas Lentigines Pigmented BCC
Types of melanoma
Superficial spreading, nodular, lentigo maligna, acral lentiginous
RF for melanoma
Fam hx Pale skin + light eyes, burns easily Red or blonde hair Hx of sunburn Hx of indoor tanning Lots of moles Increasing age Organ transplant recipients
What is the weighted 7 point checklist?
Assess melanoma Major features (2 points) = change in size, irregular shape, border or colour Minor features (1 point each) = >7mm diameter, inflammation, oozing or crusting, change in sensation
Score >3 = suspicious
Pathology of leg ulcer
Break in skin below knee that has not healed in 2 weeks
Causes of leg ulcers
Venous, diabetic, arterial disease, RA, vasculitis, sickle cell, malignancy, drugs (nicorandil, steroids, NSAIDs)
Pathology of venous leg ulcers
Sustained venous HTN, due to chronic venous insufficiency due to valve incompetence or impaired calf muscle pump
RF for venous leg ulcers
Obesity Immobility Increasing age Varicose veins Hx od DVT
Complications of venous leg ulcers
Chronic pain
Infection
Contact dermatitis
Management of leg ulcers
Compression therapy
Pentoxifylline to increase blood flow
RF for BCC
Fam hx UV exposure (head + neck common) Increasing age Male sex Skin types 1 + 2
Types of BCC
Superficial - multiple on upper trunk/ shoulders, erythematous well-demarcated scaly plaques
Nodular = solitary, shiny red nodule with large telangiectatic vessels, commonly on face
Morphoeic = more aggressive, thickened yellowish plaques
Pigmented = brown, blue, grey, seen in dark skinned pts
Basosquamous = mixed SCC + BCC
RF for SCC
UV light Fair skin HPV Ionising radiation exposure Immunodeficiency
Pathology of actinic keratosis
UV induced DNA damage Epidermal lesion characterised by: Collections of atypical keratinocytes Epidermis abnormal in architecture Mitotic figures present
Description of actinic keratosis
Small rough spots
Can become red + scaly
Management of actinic keratosis
5-FU cream Salicylic acid Diclofenac gel Imiquimod cream Cryotherapy Photodynamic therapy
What is a keloid scar?
Overgrowth of dense fibrous tissue
Extends beyond borders of wound
Management of keloid scars
Intralesional steroid injections (triamcinolone) Pressure dressings RT Cryotherapy Laser
Pathology of Kaposi’s sarcoma
Connective tissue cancer caused by herpes 8, usually in immunosuppressed pts
Spindle cells
Highly vascular
Surrounding inflammatio
Types of Kaposi’s sarcoma
Classic
Endemic/ African - affect young adult men in Africa
Transplant related
Epidemic - occurs in HIV pts
Non-epidemic - occurs in homosexual men who do not have hiv
S+S of Kaposi’s sarcoma
Skin lesions that are nodular, papular or blotchy
Around mouth, nose + throat
Management of Kaposi’s sarcoma
RT
Cryotherapy
Surgery
What is staphylococcal scalded skin syndrome?
Caused by exotocin
Prodrome of fever, irritability, skin tenderness
Sudden onset of diffuse erythema, warm + tender to touch
Flaccid bullae that desquamate in large sheets
Usually in children
What is toxic shock syndrome?
Caused by superantigen from S aureus
Presents as shock + multiorgan failure with diffuse erythematous macular rash
