Derm Flashcards
Examination of skin lesion
- Shape
- Pattern- grouped, scattered or generalised?
- Border
- Surface
- Elevation
- Colour
- Temperature
- Evolution
ABCDEF criteria to identify suspicious pigmented lesions
Asymmetry
Border irregularity or blurring
Colour variation with shades of black, brown, blue or pink
Diameter >6mm (cannot be covered by end of a pencil)
Elevation (all changing moles- size, elevation and/or colour are suspect)
Funny looking mole- stands out or different from others
Types of melanoma
Superficial spreading melanoma
Nodular melanoma- most aggressive type
Acrylic lentiginous melanoma
Lentigo maligna melanoma
Premalignant skin conditions
Acitinic keratoses
Bowen’s Disease
Treatment of mild psoriasis
Emollient
Steroids
Signs of palpation
Surface Consistency Mobility Tenderness Temperature
Open comedone
Blackhead
Closed comedone
Whitehead
Purpura
Red or purple colour (due to bleeding into the skin or mucous membrane) which doesn’t blanch on pressure
Lichenification
Well-defined roughening of skin with accentuation of skin markings
Ulcer
Loss of epidermis and dermis
Nail signs to look for on exam
Clubbing
Kolinychia
Onycholysis- psoriasis, fungal nail infection
Pitting- psoriasis, eczema and alopecia areata
Function of skin
- Protective barrier against environmental insults
- Temperature regulation
- Sensation
- Vitamin D synthesis
- Immunosurveillance
- Appearance/cosmesis
Layers of the epidermis
Stratum corneum- most superficial
Stratum granulosm
Stratum spinosum
Stratum basale- deepest layer
Urticaria, angioedema and anaphylaxis: presentation
Urticaria- itchy wheals. swelling of superficial dermis
Angioedema- swelling of tongue and lips. deeper swelling involving dermis
Anaphylaxis- bronchospasm, facial and laryngeal oedema, hypotension. can initially present with urticaria and angioedema
Management of urticaria
Antihistamines or corticosteroids if severe
Management of angioedema
Corticosteroids
Management of anaphylaxis
Adrenaline
Corticosteroids
Antihistamines
Erythema nodusm: definition and causes
Hypersenstivity to variety of stimuli
Causes: Group A- Beta haemolytic strep, primary TB, pregnancy, malignancy, IBD, chlaymida, sarcoidosis, leprosy
Erythema nodusm: presentation
Discrete tender nodules- may become confluent
1-2w and then leave bruise like discolouration as they resolve
Don’t ulcerate
Shins are most common site
Steven-Johnson syndrome and Toxic epidermal necrosis
SJS- mucocutaneous necrosis with at least two mucosal sites involved
TEN- drug induced severe disease characterised by extensive skin and mucosal necrosis accompanied by systemic toxicity
SJS and TEN: management and complications
Management: early recognition and call for help. Supportive care to maintain haemodynamic stability
Morality rate 5-12% SJS and >30% TEN- sepsis, electrolyte imbalance or multisystem organ failure
Acute meningococcal septicaemia
Features of meningitis
Non blanching purpuric rash on trunk and extremities which may be preceded by blanching maculopapular rash
Mx: Abx, prophylactic Abx for close relatives
Erythroderma- definition and causes
Exfoliative dermatitis involving at least 90% of skins surface
Cause- previous skin disease e.g. eczema or psoriasis, lymphoma, drugs or idiopathic
Erythroderma- presentation and management
Presentation:
Skin is inflamed, oedematous and scaly
Systemically unwell with lymphadenopathy and malaise
Management:
Treat underlying cause if known
Emollients and wet wraps- skin moisture
Topical steroids- inflammation
Mortality of 20-40%
Eczema herpeticum
Widespread eruption- serious complication of atopic eczema due to herpes simplex virus
Presentation- extensive crusted papules, blisters and erosions. Systemically unwell with fever and malaise
Mx- antivirals (aciclovir) and antibiotics for bacterial secondary infection.
Complications- herpes hepatitis, encephalitis, DIC and rarely death
Necrotising fascitis
Rapidly spreading infection of deep fascia with secondary tissue necrosis. Cause- group A haemolytic streptococcus
RF- abdo surgery and medical co-morbidities e.g. diabetes, malignancy
Presentation- Severe pain; erythematous, blistering and necrotic skin; systemically unwell with fever and tachycardia; presence of crepitus
Mx- urgent referral for debridement, IV Abx
Mortality up to 76%
Cellulitis: definition and causes
Deep subcutaneous tissue infection due to streptococcus pyogenes or S.aureus.
RF- immunosuppression, wounds, leg ulcers, minor skin injury
Cellulitis: presentation
Mostly lower limbs
Local signs of inflammation- swelling, erythema, warmth, pain, may be associated with lyphangitis
Systemically unwell- fever, malaise or rigors
Cellulitis: management
Abx- flucloxacillin/benzylpenicillin
Supportive care- rest, leg elevation, sterile dressings and analgesia
Complications- local necrosis, abscess and septicaemia
Staphylococcal scalded skin syndrome
Production of circulating epidermolytic toxin from benzyl-penicillin resistant staphylococci
Scald-like skin appearance, intraepidermal blistering, pain
Abx and analgesia
BCC (basal cell carcinoma): RF
UV exposure Hx of frequent/severe sunburn in childhood Skin type 1 Increasing age Male Immunosuppression Previous Hx of skin cancer Genetics
BBC : presentation
Small, skin coloured papule or nodule with surface telangiectasia and a pearly rolled egde
may have necrotic or ulcerate centre
Previously named rodent ulcer
Most common over head and neck
BCC: management
Surgical excision Radiotherapy if surgery not appropriate Crythotherapy Curettage and cautery Topical photodynamic therapy
SCC (squamous cell carcinoma): RF
Excessive UV exposure
Pre-malignant skin conditions e.g. actinic keratoses
Chronic inflammation- leg ulcers, wound scars
Immunosuppression
Genetic predisposition
SCC: presentation
Keratotic (e.g. scaly, crusty), ill-defined nodule which may ulcerate
SCC: management
Surgical excision- treatment of choice
Radiotherapy
Malignant melanoma
Invasive malignant tumour of epidermal melanocytes which has potential to metastasise.
More common on legs in women and trunk in men
Melanoma: RF
Excessive UV exposure
Skin type 1
Hx of multiple moles or atypical moles
FHx/ previous Hx of melanoma
Melanoma: Management
Surgical excision
Radiotherapy
Chemo for metastatic disease
Melanoma: Prognosis
Recurrence depends on Breslow thickness
5yr survival depends on TNM classification
Breslow thickness
Thickness of tumour
<0.76mm- low risk
0.76-1.5mm- medium risk
>1.5- high risk
Eczema: Definition and causes
Papules and vesicles on erythematous base
Defect in barrier function
Eczema: presentation
Itchy, erythematous, dry, scaly patches
More common on face and extensore aspect of limbs in infants and flexor aspects in children and adults
Acute- erythematous lesions that are vesicular and weepy
Chronic scratching/rubbing- excoriations and lichenification
Nail pitting and ridging of nails
Eczema: management
Avoid exacerbating factors
Emollients
Topical steroids
Oral antihistamines or Abx for secondary infection
Phototherapy or immunosuppression for severe non-responsive cases
Eczema: complications
Secondary bacterial infections- crusted weepy lesions
Secondary viral infection- molluscum contagiosum (pearly papules with central umbilication), viral warts, eczema herpeticum
Acne vulgaris: description and causes
Inflammatory disease of pilosebaceous follicles
Causes:
Hormonal- androgen
contributing causes- increased sebum production, abnormal follicular keratinization, bacterial colonisation and inflammation
Acne vulgaris: presentation
Non-inflammatory lesions (mild)- open and closed comedones Inflammatory lesions (moderate and severe)- papules, pustules, nodules and cysts Commonly affects face, chest and upper back
Acne vulgaris: management
Topical therapies (mild)- benzyl peroxide and topical Abx and topical retinoids Oral therapies (moderate to severe)- oral Abx, anti-androgens (females) Oral retinoids (severe acne)
Psoriasis
Description
Causes
A chronic inflammatory skin disease due to hyperproliferation of keratinocytes and inflammatory cell infiltration
Caused by complex interaction between genetic, immunological and environmental factors. Precipitating factors include- trauma, infection, drugs, stress, alcohol
Psoriasis: Types
Chronic plaque psoriasis- most common type
Guttate- raindrop lesions
Seborrhoeid- naso-labial and retro-auricular
Flexural
Pustular
Erythrodermic
Psoriasis: Presentation
Well-demarcated erythematous scaly plaques
Lesions can be itchy, burning or painful
Common on extensor surfaces of body and over scalp
Auspitz sign- scratch and gentle removal of scales cause capillary bleeding
Associated nail changes (50%)- pitting, onycholysis
Psoriatic arthropathy (5-8%)
Psoriasis: Management
Avoid precipitating factors
Emollients- reduce scales
Mild localised- topical therapies e.g. Vit D analogues, topical corticosteroids, coal tar preparations, topical retinoids
Extensive disease- phototherapy. UVB and photochemotherapy- UVA and psoralen
Extensive + severe disease/ psoriasis with systemic involvement- methotrexate, retinoids, ciclosporin, mycophenolate, biological agents
