Dermatology Flashcards
State some basic functions of the skin
- Protective barrier
- Temperature regulation
- Sensation
- Vit D synthesis
- Immunosurveillance
State 3 layers of skin
- Epidermis
- Dermis
- Hypodermis/subcutaneous tissue
State the 5 layers of the epidermis
- Stratum corneum
- Statum lucidum
- Stratum granulosum
- Stratum spinosum
- Stratum basale
*Remember, Stratum Lucidum isn’t always present (not present in thin skin)
Which layer of epidermis are melanocytes most commonly found in
Stratum basale
Compare thick and thin skin
State the thinnest areas of skin on body
- Eyelids
- Scrotum
What is the dermis made of?
What 4 structures are found in the dermis?
- Collagen, elastin, fibrillin
- Contains nerve endings, glands, hair follicles and blood vessels
State 2 functions of subcutaneous tissue/hypodermis
- Insulation
- Protective padding
Remind yourself of the Fitzpatrick skin types
*Ignore bottom bit- referring to laser hari
What is the pH of normal skin?
5.5
State some key questions you should ask when taking a dermatology history
Presenting Complaint
- Site of onset
- Evolution
- Duration
- Distribution- asymmetrical/symmetrical, flexors/extensors, mucous membranes, sun exposed sites
- Describe appearance (if can’t see in practice)
- Symptoms e.g. itchy, sore
- Exacerbating & relieving factors
- Tried any treatments: where, how much used, how long for
PMH
- History of skin diseases or atopy
- History of systemic diseases
- History of sunburn, sunbathing, sunbed use
- FH of skin diseases including atopy
- FH of autoimmune diseases
- Drug history (including timeline)
Social History
- Social
- Occupation (sun exposure, contactants), does it improve when awary from work
- Travel history
- Sexual history
ICE
- Pyschosocial impact
Discuss some key components of a good dermatological examination
KEY IDEAS: inspect, palpate, describe, systemic check
- Ensure have adequete exposure & lighting (pt should remove makeup if wearing)
- Examination of affected areas and other areas such as hair/scalp, nails, mucous membranes
- Palpate
- Examine other systems if appropriate e.g. joints (e.g. is psorasis), lymph nodes (e.g.infection, malignancy)
Define the following terms:
- Papule
- Nodule
- Erythema
- Vesicle
- Bulla
- Pustule
- Telangiecta
- Alopecia
- Hirsutism
- Excoriations
- Striae
- Papule: small lump <5mm
- Nodule: larger lump 5-10mm
- Erythema: redness
- Vesicle: small water blister
- Bulla: large water blister
- Pustule: pus-filled vesicle
- Telangiecta: thread vein
- Alopecia: hair loss/thinning
- Hirsutism: hairness
- Excoriations: scratch marks
- Striae: stretch marks
Define the following terms:
- Pruritus
- Atrophy
- Macule
- Patch
- Plaque
- Erosion
- Ulcer
- Lichenification
- Pruritus: ithcing
- Atrophy: thinning
- Macule: non palpable area of discolouration
- Patch: macule >3cm
- Plaque: palpable flat topped area >1-2cm
- Erosion: loss of epidermis (superifcial)
- Ulcer: loss of epidermis & dermis (deep)
- Lichenification: thickening of skin with exagerated skin markings
Remind yourself of the SCAM mneumonic to help you describe skin lesions
Remind yourself of the framework for describing pigmented lesions
- Asymmetry
- Border (regular or irregular)
- Colour
- Diameter
Remember to see Sem 4: Integration for clinical application for further dermatology revision
Discuss the potential psychological, social and emotional impact of skin disorders
- Decreased confidence
- Self-conscious
- Decreased involvement in activities
- Impact on education
- Pressure to try and resolve condition
- Feeling like no-one understands
What is eczema?
At what ages is it prevelant?
Atopic eczema is a chronic, ithcy, inflammatory skin condition that can affect people of all ages although 70-90% present under 5 yrs with a high incidence in 1st year
What are signs & symptoms of eczema?
- Prurutic rash
- Erythematous rash
- Dry skin
- Excoriations
- History of atopy
Disucss how you diagnose eczema
What might make you suspect that someone’s eczema is infected?
Yellow crusting, signs of systemic infection e.g. pyrexia
State the7 different types of eczema and discuss how you can distinguish between them
- Atopic dermatitis:typical widespread itchy, erythematous, dry eczema
- Contact dermatitis: eczema in response to contact with iritant or allergen
- Neurodermatitis: usually confined to one or two patches of skin- continued scratching can irritate nerve endings in skin, intensifying both itching and scratching
- Dyshidrotic eczema: small, intensely itchy blisters on the palms of hands, soles of feet and edges of the fingers and toes
- Nummular eczema: scattered circular, often itchy and sometimes oozing patches
- Seborrheic dermatitis: appears on the body where there are a lot of oil-producing (sebaceous) glands like the upper back, nose and scalp
- Stasis dermatitis: gravitational dermatitis, venous eczema, and venous stasis dermatitis, happens when there is venous insufficiency, or poor circulation in the lower legs
It is possible to have more than one type of eczema on your body at the same time. Each form of eczema has its own set of triggers and treatment requirements, which is why it’s so important to consult with a healthcare provider who specializes in treating eczema. Dermatologists in particular can help identify which type or types of eczema you may have and how to treat and prevent flare-ups.
Discuss the management of eczema
- Education regarding triggers & management
- First line= emollients
- Second line= topcial corticosteroids
- Mild= Hydrocortisone 0.1-2.5%
- Moderate= Eumovate (active ingredient= clobetasone butyrate)
- Strong= Betnovate (betamethasone 17-valerate)
- Very strong= Dermovate (clobetasol propionate)
- Third line= non-sedating antihistamine
- Fourth line= oral corticosteroids (would be with specialist at this point)
- Antibiotics e.g. flucloxacillin if infected
State 3 examples of emollients that may be used in eczema
What advice would you give patients about the use of topical steroids?
- Work by reducing inflammation: decreased redness & itching
- Steroid ointments= more oily therefore better for treating dry skin
- Wash hands
- Apply fingertip amount (last crease of finger to tip) this is enough to treat an area of skin the size of two hands with fingers together
- Avoid applying steroids with emollients as this will dilute steroids
- Wash hands afterwards
What concerns do patients commonly have about topical steroids?
- Skin thinning (if use correctly risk is very low)
- Weight gain (risk low as topical not systemic)
What advice would you give to patients in regards to emollient use?
- Explain how emollients work: form layer on top of skin that prevents water loss and helps to keep skin moist
- Diff types: (least water) ointments, creams and lotions (most water)
- Always was or dry hands thoroughly
- If emollient in tub, use spatula or clean spoon to decant emollient to prevent introduction of bacteria into tub
- Apply in stroking motion in direction of hairs
- How much: depends- if dry skin more the better. OFten advised 4/5 times a day if very dry.
What are acneirorm eruptions?
Acneiform eruptions refer to the presence of one or more of the classical features of acne vulgaris. Those are comedones, papules, pustules and nodular cysts.
What is acne vulgaris?
Who is it common in?
- Chronic, inflammatory skin condition affecting mainly face, back and chest; charcterised by blockage and inflammation of pilosebaceous unit. Presents wtih lesions that can be non-inflammatory (comedones), inflammatory (papules, pustules, nodules) or both.
- Common in adolescents
Briefly discuss the pathophysiology of acne vulgaris
- Follicylar hyperkeratinisation
- Propionibacterium acne colonisation
- Increased skin sebum production
- Complex inflammatory response involving both innate and acquired immunity
State some potential differential diagnoses for acne vulgaris
- Rosacea
- Perioral dermatitis
- Folliculitis and boils
- Drug induced acne
- Keratosis pilaris
State some signs & symptoms of acne vulgaris
- Comedones
- Open= black heads
- Closed= white heads
- Papules
- Pustules
- Nodules or cysts which are often deeper palpable lesiosn which are painful and fluctuant
- Scarring
- Pigmentation (depigmentation post inflam or hyperpigmentation)
- Seborrhoea
There is no universally agreed scoring system for acne however we can categorise into mild, moderate and severe; discuss these categories
- Mild= predominatly non-inflammed lesions
- Moderate= more widespread with increased number of inflammatory lesions
- Severe= widespread inflammatory lesions. Scarring may be present
State soem drugs and underlying conditions which can exacerbate acneform rashes
Drugs:
- Corticosteroids
- Isoniazid
- Ciclosporin
- Lithium
- Androgens
Underlying conditions:
- PCOS
State some potential causes of an allergic rash/urticaria
Discuss the management of acne vulgaris
- Advice:
- Don’t overclean face
- Gentle cleansers
- Avoid picking & squeezing spots
- Healthy diet
- Pharmacological:
- Comedonal acne: topical retinoid e.g. adapalene
- Mild inflammatory lesions: topical antibiotics (e.g. clindamycin or erythromycin), topcial retinoids & topical benzoyl peroxide. Topical antibiotic ALWAYS presribed with benzyole peroxide. Azelaic acid may also be used as an adjunct/
- Moderate inflammatory lesions: add oral antibiotic e.g. tetracycline & consider anti-androgens or COCP
- Severe, scarrring or treatment resistance: dermatology review & additional treatment e.g. oral isotretinoin)
How do topical retinoids work?
State some examples
What advice should be given to someone using topical retinoids?
- Comedolytic and anti-inflammatory. They normalize follicular hyperproliferation and hyperkeratinization. Topical retinoids reduce the numbers of microcomedones, comedones, and inflammatory lesions.
- Examples include: adapalene, tazarotene, and tretinoin
- Think stratum corneum & have been associated with photosensitivity therefore advise on sun protection
State some ADRs of isotretion
What monitoring is required when pt is on isotretion?
- Alopecia
- Dry eyes
- Headache
- Arthralgia
- Anaemia
Need monitoring of LFTs and lipids
What is conglobate acne?
What is acne fulminans?
- Conglobate acne= extensive papules and nodules which coalesce to form sinuses & cysts on trunk & upper limbs
- Acne fulminans= sudden severe inflammatory reactin with deep ulcerations and sometimes systemic effects e.g. pyrexia and athralgia
What regions of face does rosacea commonly affect?
State signs & symptoms of rosacea
Chronic, inflammatory, relapsing skin condition predominantly affecting the convexities of the centrofacial region
Signs & symptoms:
- Phymatous changes
- Persistent erythema
- Telangiectasia
- Erythema acoss nose, cheeks, forehead and chin that comes and goes (facial flushing)
- Burning or stinging sensation when using water or other products on face
- Occular roseacea: eye discomfort, dryness, itching, photophobia, blurred vision, chalazion
At what age does rosacea commonly present?
Aged 30-50yrs, more common in those with fair skin
State some common triggers for rosacea
Discuss the diagnosis of acne rosacea
Rosacea should be diagnosed and managed using a ‘phenotype approach’, based on the presenting features in each person if there is at least one ‘diagnostic’ or two ‘major’ clinical features present:
- Diagnostic features — phymatous changes, persistent erythema
- Major features — flushing/transient erythema, papules and pustules, telangiectasia, eye symptoms (ocular rosacea)
- Minor features — skin burning and/or stinging sensation, skin dryness, oedema
Discuss the management of rosacea
-
Education & lifestyle:
- Identify & avoid triggers
- Sun protection
- Signpost to sources of information
- Eyelid hygiene information & lubricating drops
- Camouflage creams
-
Papulopustular lesions:
- Topical ivermectin
- Plus oral antibiotics if severe (e.g. tetracycline or erythromycin)
-
For erythema:
- Topical brimonidine
- Referral to dermatologist, plastic surgeon or opthalmologist (if suspsect keratitis) for specialist treatment e.g. CO2 laser ablation for rhinophyma
State, and briefly describe, the 2 types of contact dermatitis- highlighting main difference in pathophysiology
- Allergic contact dermatitis: type IV hypersensitivity reaction to contact with allergens. Prior sensitisation needed.
- Irritant contatct dermatitis: non-immunological localised skin reaction due to direct contact with irritant. No prior sensitisation needed.
Which is the more common cause of contact dermatitis, allergic contact dermatitis or irritant contact dermatitis?
Irritatnt contact dermatitis (80%)
What is the most common cause of allergic contact dermatitis?
Allergy to nickel (e.g. in jewellery)
Discuss the typical presentation of allergic contact dermatitis
State some common causes
- Pruritic erythemmatous scaly rash
- Usually develops hours-days after contact with irritatnt
- Location of rash helps identify irritant e.g. cosmetics & eyelids, jewellery and fingers, wrists etc…
Common causes: cosmetics, topical medications, rubber additives, epoxy resin adhesives, plants
How is allergic contact dermatitis diagnosed?
- Skin patch testing (patch tests with suspected allergens applied to skin and observe for reaction)
- *NOTE: latex allergy is diagnosed with skin prick testing as it causes a type I hypersensitivity reaction (contact uritcaria) which presents within minutes of contact*
Discuss the management of seborrhoeic dermatitis of scalp (cradle cap) in infants
- Wash scalp regularly with baby shampoo
- Brush scalp gently with soft brush
- Scales can be soaked in olive oil, baby oil or petroleum jelly
- Topical imidazole (e.g. clotrimazole) if above doesn’ work
Discuss the management of seborrhoeic dermatits of scalp in adults
Discuss the management of seborrhoeic dermatitis of face and body in adults
Scalp
- First line= ketoconazole 2% shampoo (can also use selenium sulphide shampoo or shampoo containing salicyclic acid or coal tar)
- Second line= add in topical corticosteroid if severe itching for max of 4 weeks e.g.betamethasone valerate 0.1%
Face & Body
- Topical imidazole e.g. ketoconazole
- Add in mild corticosteroid e.g. hydrocortisone 0.5% for short duration
For venous eczema, discuss:
- What it is
- Pathophysiology
- Risk factors
- Typical presentation
- Management
- Eczema associated with chronic venous insufficiency
- Exact mechanism unknown but thought that venous hypertension results in blood constituents leaking into surroudning tissues resulting in activation of inflammatory cells and fibroblasts
- Risk factors: obesity, physical inactivity, hypertension, diabetes, older age, PMH DVT
- Presents as erythematous scaly rash involving gaiter regions
- Investigations:
- Peripheral cardiovascular examination; palpate for pedal pulses to assess for arterial insufficiency
- Ankle-brachial index
- Venous duplex ultrasound to confirm venous insufficiency
- Swabs if think secondary bacterial infection present
- Management:
- General advice e.g. elevate legs, lifestyle changes
- Emollients
- Topical steroids for acute flares
- Venous compression stockings (once ruled out arterial insufficiency)
- Treat any secondary bacterial infections with antibiotics
State, and briefly describe, the 6 types of psoriasis
- Chronic plaque psoriasis: well demarcated erythematous plaques covered by silvery white scales often found on extensor surfaces, scalp, retroauricular, perianal and periumbilical regions. Lesions are usually asymptomatic.
- Inverse/flexural psoriasis: affects flexural regions. Usually less scaley due to moisture at these sites.
- Guttate psoriasis: scaly, raindrop-shaped plaques on the trunk commonly following a streptococcal URTI
- Pustular psoriasis: white coalescing pustules which can be localised e.g. hands & feet or generalised
- Erythrodermic psoriasis: when psoriasis affects >90% of body- potentially life threatening
- Nail psoriasis: thickening of nail plate, pitting, ridging, oncholysis, subungal hyperkeratosis
Discuss how you should assess a pt with suspected psoriasis
- Examine full body (including scalp, nails, retroauricular, periumbilical & perianal regions)
- Assess for psoriatic arthritis
- Consider assessing for features of metabolic syndrome (e.g. check bp, diabestes screen etc…) as often associated with psoriasis
- Use PASI (psoriasis area & severity index score) to assess severity
- Use DLQI (dermatology life quality index) questionnaire may be done to assess impact of psorasis on this patient
For pityriasis rosea, discuss:
- What it is
- Epidemiology
- Typical presentation
- Self-limiting skin condition characterised by erythematous oval scaley eruption predominantly affecting the trunk
- Young adults (10-35yrs), females > males
- Typical presentation:
- Usually, but not always begins as a herald patch (salmon coloured plaque/patch with peripheral collarette scaling
- Within days to 3 weeks multiple smaller lesions of similar appearance develop over turnk & proximal limbs symmetrically. Lesions follow Langer lines giving christmas tree appearnce on back and V shape on upper chest
- Some pts may have mild pro-dromal period with flu like symptoms
- May be pruritic
Describe the typical presentation of lichen planus
Cutaneous lesions are described the 6 P’s; pruritic, planar (flat topped), purple, polygonal, papules or plaques:
- Pruritic, flat topped papules & plaques covered by Wicham striae (white reticular lines) involving extremeties e.g. ventral wrists, forearms, ankles, legs, oral cavity, genitalia
- Displays Koebner phenomenon
- Nail changes: longitudinal riding, scaring, splitting
- Scalp involvement may lead to scarring alopecia
Discuss the typical presentation of urticaria
- Transient (resolves 24hr)
- Non-scaley, smooth plaques with surrounding erythema
- May be associated with angioedema & anaphylaxis
Discuss the typcial presentation of each of the following subtypes of BCC:
- Nodular
- Superficial
- Morpheic/sclerosing & basosquamous
Nodular BCC
- Pearly, shiny nodule with telangiectasia- usually on head & neck region. Tend to ulcerate with time resulting in a rolled edge.
Superficial BCC
- Slow growing erythematous patch or plaque that is usually found on trunk
Morpheic/sclerosing & basosquamous
- Can only distinguish between these two histologically
- Shiny, scar-like plaque with ill defined border
Discuss the typical presentation of SCC
- Indurating (hardened) keratinising (scaley) or crusted plaques or nodules at sun exposed sights
- Lesion often symptomatic: pain, discomfort, bleeding, ulcerating, sensory changes
Acinitic keratosis and Bowen’s disease are common precursors of squamous cell carcinoma; discuss difference between the two
- AK= mutiple asymptomatic erythematous scaley macules and papules; these may be very hyperkeratotic sclaes some with cutaenous horn
- Bowen’s disease= asymptomatic well defined erythematous patches/plaques with a finer scale
We have already discussed that melanomas can be predominantly radially or predominantly vertically growing; state the types of melanoma in each
Predominantly radially growing
- Supeficial spreading melanoma (SSM)
- Acral lentiginous melanoma (ALM)
- Lentigo maligna melanoma (LMM)
Predominalty vertically growing
- Nodular melanoma
Describe the typical presentation of each of the following types of melanoma:
- Superficial spreading melanoma (SSM)
- Acral lentiginous melanoma (ALM)
- Lentigo maligna melanoma (LMM)
- Nodular melanoma (NM)
Remember the ABCDE and EFG rules for melanomas. Symptoms of skin malignancy may include: bleeding, ulceration, pain, itching, oozing & crusting). Remember some melanomas may be amelanotic (therefore be pink in colour). For all melaonas, be aware of the ugly duckling sign (lesion that stands out from others):
- Superficial spreading melanoma (SSM): begins as hyperpigmented patch growing radially, which may be asymmetric and have numerous colours
- Acral lentiginous melanoma (ALM): occurs on palms, soles or nails. May have Hutchinson sign.
- Lentigo maligna melanoma (LMM): occurs most frequenlty on face & sun exposed lesions. Typically starts as irregularly shaped, may become raised or change colour.
- Nodular melanoma (NM): hyperpigmented blue-black/amelanotic firm papule, nodule or plaque
What is Hutchinson sign in melanoma?
Extension of pigment under the nail gold; raises supsicion of subungal melanoma. It is not associated with sun exposure and is more common in Afro-Carribean & Asian ethnicities.
What is meant by dermatophytosis?
Superficial fungal infection of keratinised tissues caused by dermatophytes. Dermatophytes are a specific group of fungi known as ring worms or tineas. Various names dependent on location of fungal infection:
What is kerion?
Abscess caused by fungal infection which most commonly occurs in tinea capitis. Will require urgent referral to dermatologist and prolonged treatment with oral terbinafine
For pityriasis versicolor, discuss:
- What is is
- Aetiology/pathophysiology
- Epidemiology
- Supeficial fungal infection of skin caused by yeast (of the genus Malassezia). They are normal skin flora but can cause disease when converted to thei pathogenic hyphal form
- Common in teens & young adults (due to increased sebum production) and more common in tropical countries and in summer
Discuss how pityriasis versicolor presents
- Well demarcated thin plaques with fine scaling
- Plaques may be hyperpigmented, hypopigmented or erythematous
- Usually involves torso (can involve face)
- Can become confluent & widespread
- Post-inflammatroy pigmentary changes may persist for months despite eradication of infection
For viral warts, discuss:
- What they are
- Who common in
- Transmission
- Risk factors
- Different subtypes and presentation
- Papillomas (remember papilloma is a benign epithelial tumour) caused by HPV
- Common in childhood
- Spread via direct contact or via environment
- Risk factors: immunosupression, walking bare foot in public/shared spaces, biting nails etc…
- Subtypes & presentation:
- Plantar warts: thick hyperkeratotic plaques beneach pressure points on sole
- Verruca vulgaris: hyperkeratotic papules often on hands
- Planar warts: flat topped papules commonly occuring on face
- Condyloma acuminata (anogenital warts): cauliflower like plaques over anogential area
** Presence of thrombosed capillaries especially after paring is charcteristic of viral warts
For erythema multiforme, discuss:
- What it is
- Who it commonly affects
- Causes
- Immune mediated mucocutaenous condition most commonly caused by HSV. EM major refers to EM with mucosal involvement, EM minor only involves skin
- Young adults, slight female predilection
- Infection causes around 90% of EM; most common infectious agent is HSV followed by Mycoplasma pneumoniae. Drug induced EM <10% cases; common drug causes are NSAIDs, sulphonamides, anti-epileptics & antibiotics
Describe the presentation of erythema multiforme
- Classically presents as acrally (affecting peripheries- typically hands)
- Targetoid lesions with 3 zones: dusky central disc, pale oedematous ring, erythematous outermost ring (some lesions may only have 2 zones)
- May have mild prodromal symptoms
- Lesions may coalesce
- May have mucsosal erosions
- May be slightly pruritic
Discuss the clinical features of SJS/TEN
- Onset within 2 months of commencing causative drug
- Painful, dusky erythema with blisters & erosions
- Rapidly progress into confluent erythema with sheet-like epidermal detachment
- Nickolsky sign (epidermis detached by mechanical pressure)
- Prodromal symptoms
- Mucosal involvement is common
