Dermatology Flashcards
In an inflammatory history, what key points are different in derm?
Nature, site and progression
Recent contacts, stressful events, travel
History of atopy
Occupation and improvement away from work
DH
In a neoplastic history, what key points are different in derm?
Initial appearance and rate of change/evolution
Itch? Pain?
History of sunburn (occupation), tanning machines
Skin type
History of skin cancer/lesions & FH
Immunosupression
What are the stages of examining the skin?
Inspect
Describe
Palpate
Systematic check
How do you describe a lesion?
SCAMM Size Colour Associated secondary change (eg texture) Morphology Margin
Pigmented lesion acronym?
ABCDE Asymmetry irregular Border two or more Colours Diameter>6mm Evolution
What do you note on palpation?
Surface Consistency Mobility Tenderness Temperature
What does the systematic check include?
Nails
Scalp
Hair
Mucous membranes
What is the derm way of saying mole?
Pigmented melanocytic naevus
What is a comedome?
A plug in a sebaceous follicle, containing altered sebum, bacteria and cellular debris
Open (blackhead), closed (whitehead)
What sites are described as flexural?
Body folds (groin, neck, behind ears, popliteal fossae, antecubital fossae)
What sites are described as extensor?
Sacrum, buttocks, ankles, heels
What is a Köebner?
A linear eruption arising at site or trauma
Opposite of discrete?
Confluent
What is purpura?
Red/purple due to bleeding into skin, does not blanche on pressure
Petechiae if small, ecchymoses are larger bruise like patches
What is eccyhymoses?
Big bruise-like pupura
What are flat lesions described as?
Small: macule
Larger: patch
What are raised lesions called?
Small: papule
Large and domed: nodule
Large and table top: plaque
What is a vesicle? eg?
Small raised fluid filled lesions
eg in varicella zoster
What is larger than a vesicle?
A bulla
What is a pus containing lesion called?
Small: pustule
Large: Abscess
What can staph infection in the skin form?
Small: boil/furuncle around hair follicle
Large: Carbuncle
What is it called if someone scratches off the epidermis (eg in eczema)
Excoriated lesion
What are scales?
Flakes of stratum corneam
What is it called when you lose epidermis/dermis
Loss of epidermis: erosion
Loss of dermis: ulcer
What is it called when you lose a patch of hair?
Alopecia
What is koilonychia?
Spoon shaped nail
Iron deficiency
What happens to the nails in psoriasis?
Onchylosis (nail comes away from nail bed distally)
Pitting
Craggy
6 functions of the skin
Protective barrier Thermoregulation Sensation Vit D synthesis Immunosurveillance Appearance/cosmetic
Name the skin appendages
Nails
Hair
Sebaceous glands
Sweat glands
Name the cell types found in the epidermis
Keratinocytes (produce keratin barrier)
Langerhans’ (antigen presenting)
Melanocytes (pigment, protects from UV)
Merkel (specialised nerve endings)
Layers of the epidermis
Stratum basale (stem cells) Stratum spinosum Stratum granulosum (secretion of lipid) Stratum corneum (keratin)
What is beneath the stratum corneum on the soles of the feet?
Stratum lucidum
What does the dermis mainly consist of?
Collagen Elastin Glycosaminoglycans Fibroblasts Immune cells nerves Skin appendages Lymphatics Blood vessels
What are the 3 main types of hair?
Lanugo (fine long hair in fetus) Vellus (fine short hair all over body) Terminal hair (coarse long hair on scalp, eyebrows, eyelashes and pubic areas)
What are the stages of hair growth?
Anagen (long growing phase)
Catagen (short regressing phase)
Telogen (resting/shedding phase)
What are the 2 different types of sweat glands and difference?
Eccrine: everywhere
Apocrine: axillae, areolae, genitalia and anus
What happens to the skin in anaphylaxis?
Urticaria and angioedema
What is urticaria?
Local increase in permeability of capillaries and small venules due to prostaglandins, leukotrienes, and HISTAMINE
Swelling of the superficial dermis raising the epidermis into wheals
What is angioedema?
Deeper swelling that involves dermis and subcutaenous tissues
Esp tongue and lips
Treatments of urticaria, angioedema and anaphylaxis?
Urticaria: antihistamines
Angioedema: Corticosteroids
Anaphylaxis: Adrenaline, corticosteroids and antihistamines
Diagnostic criteria of atopic eczema
itchy skin
flexural involvement (visible/history of)
Personal history of asthma/hayfever (or if under 4, parents/siblings)
Dry skin over last year
Onset under age 2
Different types of emollients
Ointment cream lotion bath oils soap substitutes
Name 4 topical steroids, weakest first
Hydrocortisone 1% Clobetasone Butyrate (Eumovate) Bethamethasone valerate (Betnovate) Clobetasol Propionate (Dermovate)
Which is stronger: Eumovate or Betnovate?
Betnovate
How to treat severe infected eczema
Emollients/ointments
Potent topical steroids
Flucloxicillin for bacterial infection
How would you describe classic chronic psoriasis?
Red scaly plaque, well demarcated edges
Due to hyperproliferation of keratinocytes and inflammatory cell infiltration
Name the areas most commonly affected by psoriasis
Scalp, exterior knees and elbows, lower back
Describe 5 nail changes seen in psoriasis
Nail pitting
Onchylosis (excessive proliferation of nailbed)
Salmon patch (discolouration in nailbed)
Beau’s lines (transverse, intermittent inflammation)
Leukonychia
What non-cutaneous manifestation of psoriasis is there?
Arthropathy
5-8% of psoriatic patients
Treatment of psoriasis
Emollients
Topical (coal tar, corticosteroids, vit D analogues, dithranol, keratolytics)
Phototherapy (UVB, PUVA)
Oral (methotrexate, cyclosporin, oral retinoids, mycophenolate mofetil)
Biological agents (infliximab, etanercept)
Describe eczema dermatology style
Macular papular rash affecting mainly the flexor surfaces.
Scaling crust secondary to infection
No well defined borders and always pruritic
Affects 20% of under 12s
Symptoms of rosacea
Telangiectasia
Aggravated by hot and spicy drinks and food and sun exposure
Sensitive skin: burning and itching with creams/makeup
Papules and pustules on nose/forehead/cheeks and chin
Rhinophyma & erythema
Treatments of rosacea
Topical metronidazole
If mod-severe papulopustular: tetracyclines (lymecycline)
How do you manage dermatitis of the scalp?
Ketoconazole 2% shampoo (or selenium sulphide) BD for at least a month
4 weeks of potent topical corticosteroid?
How do you manage dermatitis of the face?
2% ketoconazole cream
Hydrocortisone 0.5%
Eyelid hygiene
Signs of a nodular BCC?
Small shiny skin coloured/pinkish lump Central necrosis/ulcer/crust Rolled pearly edge Telangiectasia Bleed spontaneously and heal over
What are the main treatments of BCCs?
Surgical excision
Mohs micrographic surgery (expensive)
If frail/no surgery: radiotherapy
If superficial: cryotherapy/5FU
What is SCC in situ also called?
Bowen’s disease
Treatment of Bowen’s?
5-flurouracil cream
Cryotherapy
Curettage and cautery
Photodynamic therapy if difuse
Features of Bowen’s
Can often look like a small patch of psoriasis
Red inflammatory base, plaque
Characteristic tiny regular clods of blood vessels
Disordered structure
Well defined border
Keratin scale
Features of actinic keratosis?
Flat patch
Strawberry pattern of erythema
Risk factors for melanoma
Sun exposure
Susceptible genes
Type 1 fair skin
Atypical naevi elsewhere
What is atypical mole syndrome?
> 50 moles
>3 are atypical
Difference between pemphigus vulgaris and bullous pemphigoid
PV: flaccid, common mouth involvement, intraepidermal split, Desmoglein antigen
BP: tense, no mouth involvement, subepidermal split, basement membrane antigen
Which blistering disease is most fatal?
Bullous pemphigoid
Up to 41%
Which blistering disease commonly affects those above 70yrs?
Bullous pemphigoid
Treatment of blistering diseases?
Oral corticosteroids in pemphigus vulgaris and BP if severe
Topical corticosteroids in BP if not severe
What is dermatitis herpetiformis associated with
IgA
Coeliac disease
List 4 causes of erythroderma
Psoriasis
Dermatitis
Drug eruptions
Cutaneous T cell lymphoma
What is eczema herpeticum?
HSV-1 infection on eczematous skin
Treatment of eczema herpeticum
Acyclovir
Emollients
Antibiotics for secondary skin infection
What is staphylococcal scalded skin syndrome?
Epidermolytic toxin released from staph phage II Usually infants Intraepidermal blistering Low mortality Treat with antibiotics (erythromicin)
What is toxic epidermal necrolysis?
Drug induced full thickness epidermal necrosis with sub epidermal detachment
Any age
Mortality roughly % body affected
Treat by withdrawing drug
What usually causes necrotising fasciitis?
Group A haemolytic strep
More common in malignancy&diabetes
Treatment of necrotising fasciitis?
Surgical debridement
IV antibiotics
Presentation of necrotising fasciitis
Inflammation of body part Pain far beyond what would be expected Rapidly advancing Vascular occlusion, ischaemia, necrosis Fever, eiosinophilia, ALT>1000
1st line treatment of impetigo
Fusidic acid
Usual pathogens for impetigo and cellulitis?
Staph aureus, strep pyogenes
What usually causes warts?
How long do warts last with no treatment?
Human papilloma virus
2 yrs
Treatment options for warts
Cryotherapy
Topical salicylic acid
Describe molluscum contageousum like a dermatologist
Firm smooth umbilicated papules, 2-5mm in diameter
Skin colour/white/translucent
Usually in clusters
Treatment of mild acne
1st: topical retinoid, benzoyl peroxide
2nd: Azelaic acid
3rd: Combined oral contraceptive
Treatment of moderate/severe acne
Lymecycline + topical retinoid
Dianette COCP
When would you treat acne with isotertinoin?
If severe, hasn’t responded to antibiotics, depression and scarring
Whats the main risk of isotretinoin?
Teratogenicity
What is erythema nodosum?
Discrete tender nodules due to a hypersensitivity reaction to group A haemolytic strep/TB/pregnancy/malignancy/sarcoidosis/IBD/chlamydia/leprosy
What causes erythrma multiforme?
Herpes simplex?
What does the skin look like in acute meningococcaemia?
Non blanching purpuric rash on the trunk and extremities
-> haemorrhagic bullae and tissue necrosis
What are the complications of meningococcal septicaemia?
Septic shock
Disseminated intravascular coagulation
Multiorgan failure
Death
What is erysipelas?
Acute superficial form of cellulitis (dermis and upper subcutaneous tissue)
Has well defined red raised border
3 main forms of superficial fungal infections
Dermatophytes (ring worm/tinea)
Yeasts (candidiasis)
Moulds (aspergillus)
What does tinea look like?
Unilateral, itchy Circular/annular/polygonal lesions with clearly defined raised and scaly edges In nail: yellow thickened crumbling nail Areas fail to tan Purple w/Wickham striae
What does candidiasis look like?
White plaques on mucosal areas
Erythema with satellite lesions in flexure
Management of fungal infections?
Skin scrapings/nail clippings for diagnosis Treat underlying immunosupression? Decrease moist environment Topical antifungals (terbinifine cream) Oral if severe (itraconazole)
Describe SCC lesion
Locally invasive, potential to metastasise
Karatotic (scaly/crusty) ill defined nodule which may ulcerate
Main prognostic factor in melanoma?
Depth (Breslow thickness on biopsy)
>0.76cm med risk
>1.5cm high risk
Cause of eczema
Primary genetic defect in skin barrier function
Loss of function of protein filaggrin
Types of psoriasis
% population?
Chronic plaque Seborrhoeic (naso-labial, retroauricular) Pustular Erthrodermic Guttate 2% population
3 main types of ulcer
3 not so common causes
Arterial
Venous
Neuropathic
Infection(leischmaniasis), vasculitic, carcinoma
Venous ulcer features
Treatment?
Painful, worse on standing
Hx of varicose veins/DVT
Medial malleolar area
Large shallow irregular ulcer with an exudative granulating base
Warm skin, normal peripheral pulses
haemosiderin and melanin deposit, white scarring
TREAT: compression bandaging
Arterial ulcer features
Painful at night, worse on elevation
Hx of atherosclerosis
Found on pressure and trauma sights (pretibial, toes)
Small sharply defined deep (punch out lesions)
Necrotic base
Cold skin, weak peripheral pulses, shiny pale skin and hair loss
Arterial ulcer investigations and treatment
ABPI<0.8 Arterial insufficiency Doppler and angiography Vascular reconstruction NOT compression bandaging!
Features of a neuropathic ulcer
Painless, abnormal sensation Hx diabetes/neurological disease Pressure points (soles/heels/toes) Granulating base, callus Warm skin, normal pulses, peripheral neuropathy
Investigations and treatment in neuropathic ulcers
X ray to exclude osteomyelitis Wound debridement Regular repositioning Appropriate footwear Good nutrition
Where do you often find scabies?
Sides of fingers Finger webs Wrists, elbows, ankles, feet Nipples and genitals Look like linear burrows/rubbery nodules -> worse at night, V ITCHY, spares head
Treatment of scabies
Scabicide (permethrin/malathion)
Antihistamines
Function of fillagrin?
Binds keratin and hyaline into kerato-hyaline granules
This function is lost in eczema/dermatitis
Why is erythroderma dangerous?
Fluid and electrolyte balance is lost
High output cardiac failure
Septicaemia can occur
What is added in PUVA?
Topical psoralen to increase effectiveness of UVA
What is PASI?
Psoriasis area and severity index Areas affected & % of body Erythema Induration (thickness) Desquamation (scaling)
Name 9 subtypes of eczema
Atopic (most common)
Eczema herpeticum (when infected with HSV1)
Pompholyx eczema (palms and soles, sweating)
Discoid
Venous (haemosiderin deposits in legs, oedema, lipidomatosclerosis)
Allergic and irritant dermatitis
Seborrhoeic dermatitis (1st yr of life, immune reaction to yeast)
Chronic actinic dermatitis
Astatic (elderly, dry legs)
Name 2 non sedating antihistamines
Cetirizine
Fexofenadine
Causes of vasculitis
Viral hepititis Autoimmune (SLE, Sjögrens, RA, ulcerative colitis) Strep, staph Drugs (thiazides, iodines, penicillin) Lymphoproloferative
Signs of HSV1&2
HSV1: generally oral HSV2: generally genital Pain/burning preceded lesion Grouped vesicles->pustules->erosions->ulcers Scalloped edges Single ganglia affected
What is Ramsay Hunt Syndrome?
Varicella Zoster reactivation (shingles)
Causes facial nerve palsy
What is a pyogenic granuloma?
Overgrowth of blood vessels (esp after minor trauma)
Comes up over 3 months and bleeds profusely
Treatment of typical cellulitis versus cat/dog bite
Amoxicillin/fluclox
Dog/cat bite: Co-amoxiclav
