Derm Flashcards
Malignant Melanoma
Features of Malignant Melanoma?
Asymmetry
Border: irregular
Colour: non-uniform
Diameter > 6mm
Evolving / Elevation
Risk factors for Malignant Melanoma?
Sunlight: esp. intense exposure in early years.
Fair skinned (Low Fitzpatrick Skin Type)
↑ no. of common moles
+ve FH
↑ age
Immunosuppression
Types of Malignant melanoma?
Superficial Spreading: 80%
- Irregular borders, colour variation
- Commonest in Caucasians
- Grow slowly, metastasise late = better prognosis
Lentigo Maligna Melanoma
- Often elderly pts.
- Face or scalp
Acral Lentiginous
- Asians/blacks
- Palms, soles, subungual (w Hutchinson’s sign)
Nodular Melanoma
- All sites
- Younger age, new lesion
- Invade deeply and metastasis early = poor prog
Amelanotic
- Atypical appearance → delayed Dx
Irregular borders, colour variation
Commonest in Caucasians
Grow slowly, metastasise late = better prognosis
which type of malignant melanoma?
Superficial Spreading
most common
Often elderly pts.
Face or scalp
Which type of malignant melanoma?
Lentigo Maligna Melanoma
Asians/blacks
Palms, soles, subungual (w Hutchinson’s sign)
Which type of malignant melanoma?
Acral Lentiginous
Staging and Prognosis of Malignant Melanoma?
Breslow Depth
Thickness of tumour to deepest point of dermal invasion
<1mm = 95-100% 5yrs
>4mm = 50% 5ys
Clark’s Staging
Stratifies depth by 5 anatomical levels
Stage 1: Epidermis
Stage 5: sc fat
mx og malignant melanoma?
Excision + 2O margin excision depending on Bres depth
± lymphadenectomy
± adjuvant chemo (may use isolated limb perfusion)
melanoma
poor prognostic indicators?
Male sex (more tumours on trunk > females)
↑ mitoses
Satellite lesions (lymphatic spread)
Ulceration
Actinic keratosis
Irregular, crusty warty lesions.
Pre-malignant (~1%/yr)
Mx of Actinic Keratoses?
- pre malignant
Cautery
Cryo
5-FU
Imiquimod
Photodynamic phototherapy
What is Bowens disease?
Red/brown scaly plaques
SCC in situ
Evolution of actinic keratoses?
Actinic keratoses -> bowens -> SCC
LN spread is rare
features of squamous cell carcinoma?
Ulcerated lesion w hard, raised everted edges
Sun exposed areas
Causes of SCC?
Sun exposure: scalp, face, ears, lower leg
May arise in chronic ulcers: Marjolin’s Ulcer
Xeroderma pigmentosa
mx of SCC?
Excision + radiotherapy to affected nodes
most common skin cancer?
Basal cell carcinoma
features of Basal cell carcinoma?
Commonest cancer
Pearly nodule w rolled telangiectactic edge
May ulcerate
Typically on face in sun-exposed area
Above line from tragus → angle of mouth
Locally invasive
v rarely metastasize
mx of Basal cell carcinoma?
Excision:
Mohs: complete circumferential margin assessment using frozen section histology
Cryo/radio may be used.
Psoriasis
pathology of Psoriasis?
T4 hypersensitivity reaction
Epidermal proliferation
T-cell driven inflammatory infiltration
Histo: Acanthosis: thickening of the epidermis
Parakeratosis: nuclei in stratum corneum
Munro’s microabscesses: neutrophils
Histology shows
Acanthosis: thickening of the epidermis
Parakeratosis: nuclei in stratum corneum
Munro’s microabscesses: neutrophils
Psoriasis
Triggers for psoriasis?
Stress
Infections: esp. streps
Skin trauma: Kobner phenomenon
Drugs: β-B, Li, anti-malarials, EtOH
Smoking
Signs of Psoriasis?
Plaques
Symmetrical well-defined red plaques w silvery scale
Extensors: elbows, knees
Flexures (no scales): axillae, groins, submammary
Scalp, behind ears, navel, sacrum
Nail Changes (in 50%)
Pitting
Onycholysis
Subungual hyperkeratosis
10-40% Develop Seronegative Arthritis
Mono-/oligo-arthritis: DIPs commonly involved
Rheumatoid-like
Asymmetrical polyarthritis
Psoriatic spondylitis
Arthritis mutilans
May → dactylitis
features of psoriatic plaques?
usually on extensors and flexures
Symmetrical well defined salmon pink plaques w silvery scale
what nail changes are assoc w psoriasis?
pitting
onycholysis
subungal hyperkeratosis
Guttate Psoriasis
Drop-like salmon-pink papules w fine scale
Mainly on trunk
Occurs in children assoc. w strep infection
what infection does guttate psoriasis commonly occur after?
strep
Differential of Psoriasis?
Eczema
Tinea: asymmetrical
Seborrhoeic dermatitis
What is pustular psoriasis?
Sterile pustules (filled w pus)
May be localised to palms and soles
Generalised Pustular Psoriasis
Generalised exfoliative dermatitis
Severe systemic upset: fever, ↑WCC, dehydration
May be triggered by rapid steroid withdrawal
Generalised exfoliative dermatitis
Severe systemic upset: fever, ↑WCC, dehydration
May be triggered by rapid steroid withdrawal
what type of skin disorder?
Generalised pustular psoriasis
Mx of Psoriasis?
Education: Avoid triggers
Soap Substitute: Aqueous cream, Dermol cream
Emollients: Epaderm, Dermol, Diprobase
Topical Therapy: Vit D3 analogue: e.g. calcipotriol
Steroids: e.g. betamethasone
Tar: mainly reserved for in-patient use
Retinoids: e.g. tazarotene
UV Phototherapy: Causes local immunosuppression
Non-Biologicals: Methotrexate, Ciclosporin, Acetretin (oral retinoid / vit A analogue)
Biologicals: ustekinumab (IL12/23), Secukinumab (IL17A), Infliximab (anti-TNFa)
What biologics are available for Psoriasis?
Ustekinumab (anti IL12/ IL23)
Secukinumab (anti IL17a)
Infliximab, Etanercept, Adalimumab
What can Secukinumab (anti-IL17A) be used for?
Psoriasis
Ank Spondylitis
Psoriatic arthritis
what is Ustekinumab anti-IL12/23 used for?
Psoriasis
Psoriatic arthritis
Crohns Disease
UV phototherapy in Psoriasis?
Narrow Band UVB
PUVA: Psoralen + UVA
Psoralen is a photsensitising agent and can be topical or oral
PUVA is more effective but ↑ skin Ca risk
Presentation of Eczema?
Extremely itchy, Poorly demarcated rash
Acute: oozing papules and vesicles
Subacute: red and scaly
Chronic eczema → lichenification
- Skin thickening w exaggeration of skin markings
Causes of Atopic Eczema?
TH2 driven inflammation w ↑IgE production
FH of atopy common
Specific allergens: House dust mite, Animal dander
Diet: e.g. dairy products
Presentation of atopic eczema?
Face: esp. around eyes, cheeks
Flexures: knees, elbows
May become 2O infected
- Staph → fluclox
- HSV → aciclovir
Atopic eczema assoc w?
Hay fever
Asthma
Ix of eczema?
↑ IgE
RAST testing: identify specific Ag
Common causes of irritant contact dermatitis?
detergents, soaps, oils, solvents, venous stasis
Common allergens of Allergic Contact Dermatitis?
Type IV hypersensitivity reaction
Nickel: jewellery, watches, coins
Chromates: leather
Lanolin: creams, cosmetics
ix of allergic contact dermatitis?
Patch testing
Cause of Seborrhoeic Dermatitis?
overgrowth of skin yeasts (e.g. malassezia furfur)
features of seborrhoeic dermatitis?
Red, scaly, rash
Location: scalp (dandruff), eyebrows, cheeks, nasolabial folds
Mx of seborrhoeic dermatitis?
scalp:
OTC preparations containing zinc pyrithione (‘Head & Shoulders’) and tar (‘Neutrogena T/Gel’) are first-line
2nd line: ketoconazole
selenium sulphide and topical corticosteroid may be useful
face and body:
topical antifungals e.g. ketoconazole
topical steroids
Mx of atopic eczema?
Education: Avoid triggers: e.g. soap
Soap Substitute: Aqueous cream, Dermol cream
Emollients: Epaderm, Dermol
Topical Therapy: Steroids
- 1% Hydrocortisone: face, groins
- Eumovate: can use briefly (<1wk) on face
- Betnovate
- Dermovate: very strong, brief use on thick skin like Palms, soles
2nd line Therapies: Topical tacrolimus, Phototherapy, Ciclosporin or azathioprine
Causes of generalised pruritus?
CRF
Cholestasis
Haematological: Polycythaemia, Hodgkin’s, Leukaemia, Iron deficiency
Endocrine: DM, Hyper- / hypo-thyroidism, Pregnancy
Very itchy dermatological diseases
differential?
Eczema
Urticaria
Scabies
Dermatitis herpetiformis
What is Eczema Herpeticum
first episode of infection with Herpes simplex HSV1
Risk factors for candida infection
immunosuppression, Abx, steroid inhalers
features of candidiasis?
Pink + white patches
Moist
Satellite lesions
Mouth, vagina, skin folds, toe web
Mx of candidiasis?
Mouth: nystatin
Vagina: clotrimazole cream and pessary
Pityriasis vesicolor
What organism causes Pityriasis Versicolor?
malassezia furfur
presentation of pityriasis versicolor?
Common in hot and humid environments
Circular hypo-/hyper-pigmented patches
Fine white scale
Itchy
Back of neck and trunk
Ix of pityriasis versicolor?
“Spaghetti and meatballs” appearance w KOH stain
Mx of pityriasis versicolor?
Selenium sulphate or ketoconazole shampoos
Impetigo
features of Impetigo?
Age: peak @ 2-5yrs
Honey-coloured crusts on erythematous base
Common on face
What organism is responsible for Impetigo?
Staph aureus
Mx of Impetigo?
Mild: topical Abx (fusidic acid, mupirocin)
More severe: fluclox PO
Pityriasis rosea
- herald patch
features of pityriasis Rosea?
HHV-6/-7
Herald patch precedes rash, mainly on the trunk
fir tree appearance of rash
features of Shingles/ herpes zoster?
Recurrent VZV infection
Dermatomal distribution of cropping vesicles and crust
Thoracic: 50%,
Ophthalmic: 20% -> Cornea affected in 50% → keratitis, iritis
May → post-herpetic neuralgia
Mx of Shingles?
Aciclovir or famciclovir PO if severe
Features of herpes simplex?
Gingivostomatitis or recurrent genital or oral ulcers
Triggered by infection (e.g. CAP), sunlight and immunosuppression
May complicate eczema: eczema herpeticum
Grouped painful vesicles on an erythematous base
Mx of herpes simplex
aciclovir or famciclovir indicated if immunosuppressed or recurrent genital herpes
pink papules w umbilicated central punctum
resolve spontaneously in most
Pox virus
Molluscum contagiosum
what organism is responsible for molluscum contagiosum?
pox virus
Mx of genital warts (HPV)?
Expectant
Destructive:
Topical salicylic acid
Cryotherapy
Podophyllin
Imiquimod
What is Erysipelas?
Sharply defined superficial infection by S. pyogenes
Often affects the face
High fever + ↑ WCC
more superficial, raised and demarcated compared to cellulitis
features of cellulitis?
Acute infection of skin and soft tissues
Deeper and less well defined than erysipelas
Pain, swelling, erythema and warmth
Systemic upset
± lymphadenopathy
Causes of cellulitis?
Group A Strep + Staph Aureus
Mx of cellulitis?
Empiric: fluclox IV
Confirmed Strep: Benpen or Pen V
Pen allergic: clindamycin
pathophysiology of acne vulgaris?
↑ sebum production: androgens and CRH
P. acnes is a skin commensal that flourishes in the anaerobic environment of the blocked follicle → inflammation
features of acne vulgaris?
Inflammation of pilosebaceus follicles
Comedones (white- or black-heads), papules, pustules nodules, cysts
Face, neck, upper chest and back
Mx of mild acne vulgaris?
Pt. education
Remember that topical therapy is difficult to apply to the back.
topical therapy: Benzoyl peroxide
Erythromycin, Clindamycin
Tretinoin / Isotretinoin
Mx of moderate acne vulgaris?
Pt. education
Remember that topical therapy is difficult to apply to the back.
Topical benzoyl peroxide + oral Abx (doxy or erythro)
Mx of severe acne vulgaris?
Isotretinoin (vitamin A analogue)
- 60-70% have no further recurrence
- SE: teratogenic, hepatitis, ↑lipids, depression, dry skin, myalgia
- Monitor: LFTs, lipids, FBC
May try Co-cyprindiol (cyproterone acetate and ethinylestradiol) in women
What should u monitor in pt on isotretinoin?
LFTs, lipids, FBC
SE: teratogenic, hepatitis, ↑lipids, depression, dry skin, myalgia
features of acne rosacea?
Chronic relapsing remitting disorder affecting the face
Chronic flushing ppted. by alcohol or spicy foods.
Fixed erythema: chin, nose, cheeks, forehead
Telangiectasia, papules, pustules (no comedones)
Acne rosacea assoc w?
Rhinophyma: swelling and soft tissue overgrowth of the nose in males
Blepharitis: scaling and irritation at the eyelashes
Mx of acne rosacea?
Avoid sun exposure + daily applications of sun screen
topical metronidazole may be used for mild symptoms (i.e. Limited number of papules and pustules, no plaques)
more severe disease is treated with systemic antibiotics e.g. Oxytetracycline
camouflage creams may help conceal redness
laser therapy - for patients with prominent telangiectasia
Lichen Planus
Flexors: wrists, forearms, ankles, legs
Display Kobner phenomenon
Purple, Pruritic, Polygonal, Planar, Papules
Lacy white marks: Wickham’s Striae
Other than skin, where else can you find Lichen Planus?
Scalp: scarring alopecia
Nails: longitudinal ridges
Mouth: lacy white plaques on inner cheeks
Genitals
Wickhams striae?
Lichen Planus
- lacy white marks
features of Lichen Planus
Flexors: wrists, forearms, ankles, legs
Display Kobner phenomenon
Purple, Pruritic, Polygonal, Planar, Papules
Lacy white marks: Wickham’s Striae
Mx of Lichen Planus?
Mild: topical steroids
Severe: systemic steroids
Bullous Pemphigoid
tense bullae on erythematous base
autoimmune blistering disease due to auto abs against hemidesmosomes
pathophysiology of bullous pemphigoid?
Autoimmune blistering disease due to auto-abs against hemidesmosomes
features of bullous pemphigoid?
Mainly affects the elderly
Tense bullae on erythematous base
Can be itchy
Ix of bullous pemphigoid?
Biopsy shows linear IgG along the BM and subepidermal bullae
mx of bullous pemphigoid
Refer to dermatologist for biopsy and confirmation of diagnosis
Oral corticosteroids are mainstay of tx
Topical corticosteroids, immunosuppressants and antibiotics are also used
features of pemphigus vulgaris?
Younger pts.
Large flaccid bullae which rupture easily
Nikolsky’s sign +ve
Mucosa is often affected
pathophysiology of pemphigus vulgaris?
Autoimmune blistering disease due to auto-abs against desmosomes.
May be ppted by drugs: NSAIDs, ACEi, L-dopa
Ix of pemphigus vulgaris?
Intraepidermal bullae (superficial)
Mx of pemphigus vulgaris?
Prednisolone
Rituximab
IVIg
What drugs may precipitate Pemphigus vulgaris?
NSAIDs
ACEi
l-dopa
Mx of head lice?
Malathion
combing - fine tooth to get rid of lice
features of head lice?
itch
papular rash @ nape of neck
Mx of scabies?
Permethrin cream: applied from neck down for 24hrs
2nd line: Malathion
3rd line: oral ivermectin
Treat all members of the household
Burrows: short, serpiginous grey line, block dot
Hypersensitivity rash: eczematous, vesicles
Extremely itchy → escoriation
Particularly affects the finger web spaces (esp. 1st)
Also: axillae, groin, umbilicus
Scabies
features of scabies?
highly contagious: spread by direct contact
Burrows: short, serpiginous grey line, block dot
Hypersensitivity rash: eczematous, vesicles
Extremely itchy → escoriation
Particularly affects the finger web spaces (esp. 1st)
Also: axillae, groin, umbilicus
commonest type of skin problem from drugs?
maculopapular rash
- Generalized erythematous macules and papules
± fever and ↑ eosinophils
Develops w/i two weeks of onset of drug
e.g. penicillins, cephalopsporins, AEDs
Causes of Erythema Multiforme?
Idiopathic
Infections: HSV, mycoplasma
Drugs: Sulphonamides, NSAIDs, allopurinol, penicillin, phenytoin
Symmetrical target lesions on palms, soles and limbs
Erythema Multiforme
Occurs 1-2wks after insult
Infections are commoner cause of EM
What is Stevens-Johnson syndrome?
More severe variant of EM,
Blistering mucosa: conjunctiva, oral, genital
skin detachment <10% of body surface
What is toxic epidermal necrolysis?
Extreme form of SJS (skin involvement >30%)
Nearly always a drug reaction
Severe mucosal ulceration
Widespread erythema followed by epidermal necrosis w loss of large sheets of epidermis → dehydration
+ve Nikolsky’s sign: epidermis separates with mild lateral pressure
↑↑↑ risk in HIV+
Mx of Toxic Epidermal Necrolysis?
Supportive
Dexamethasone
IVIg
what condition increases risk of toxic epidermal necrolysis?
HIV +ve
Livedo Reticularis
Persistent mottled red/blue lesions that don’t blanch
Commonly found on the legs
Triggered by cold
Causes of livedo reticularis?
idiopathic
vasculitis: RA, SLE, PAN
Obstruction: anti-phos, cryoglobulinaemia
Sneddon’s syndrome: Livedo reticularis + CVAs
skin manifestation of Rheumatic fever?
erythema marginatum
Skin manifestations of Lyme Disease?
Erythema chronicum migrans
skin manifestations of crohns disease?
Perianal ulcers and fistulae
Erythema nodosum
Pyoderma gangrenosum
Skin manifestations of dermatomyositis?
Heliotrope rash on eyelids
Shawl sign (macular rash)
Gottron’s Papules
Mechanic’s hands
Nailfold erythema, telangiectasia
Skin manifestations of DM?
Ulcers
Candida
Kyrle disease
Acanthosis nigricans
Necrobiosis lipoidica (shins) Granuloma annulare (hands, feet)
Skin manifestations of sarcoidosis?
Erythema nodosum
Erythema multiforme
Lupus pernio
Hypopigmented areas
Red/violet plaques
Skin manifestations of Coeliac?
Dermatitis herpetiformis (elbows)
skin manifestations of Graves?
Pre-tibial myxoedema (lat mal)
skin manifestations of Rheumatoid arthritis?
Rheumatoid nodules
Vasculitis (palpable purpura)
Skin manifestations of systemic sclerosis?
Calcinosis
Raynaud’s
Sclerodactyly
Telangiectasia
Generalised skin thickening
skin manifestations of SLE?
facial butterfly rash
Skin manifestations of liver disease?
Palmar erythema
Spider naevi
Gynaecomastia
↓ 2O sexual hair
Jaundice
Bruising
Excoriations
Skin manifestations w chronic kidney failure?
Assoc w Cause
- DM, vasculitis, sclero, RA, SLE
Assoc w ESRD
- Pruritus, xerosis, pigment change, Bullous disease
Assoc. w Transplant
- Cushingoid, gingival hyperplasia,
Infections, BCC, SCC, melanoma Kaposi’s
Skin manifestations of neoplasia?
Dermatomyositis
Thrombophlebitis migrans
Acquired ichthyosis
thickened, velvety, relatively darker areas of skin on the neck, armpit and in skin folds
Acanthosis nigricans
associated with obesity or endocrinopathies e.g DM, cushings, PCOS
autoimmune condition causing localised, well demarcated patches of hair loss.
Alopecia areata
mx of Alopecia areata?
autoimmune condition causing localised, well demarcated patches of hair loss.
Hair will regrow in 50% of patients by 1 year, and in 80-90% eventually.
Careful explanation is therefore sufficient in many patients.
What is Koebner phenomenon?
new skin lesions appearing at the site of trauma
e.g. in psoriasis, lichen planus
mx of lichen planus?
topical steroids are the mainstay of treatment
benzydamine mouthwash or spray is recommended for oral lichen planus
extensive lichen planus may require oral steroids or immunosuppression
What is the single most important prognostic marker in malignant melanoma?
invasion depth of the tumour (Breslow depth)
what drug may cause pellagra?
isoniazid
diagnostic criteria in HHT?
4 main diagnostic criteria.
2 = possible diagnosis of HHT.
3 or more = definite diagnosis of HHT:
epistaxis : spontaneous, recurrent nosebleeds
telangiectases: multiple at characteristic sites (lips, oral cavity, fingers, nose)
visceral lesions: for example gastrointestinal telangiectasia (with or without bleeding), pulmonary arteriovenous malformations (AVM), hepatic AVM, cerebral AVM, spinal AVM
family history: a first-degree relative with HHT
mx of pityriasis rosea?
no mx required
self-limiting skin condition
usually disappears after 4-12 weeks
mx of lichen sclerosus?
topical steroids and emollients
margins of excision of a melanoma are dependent on?
breslow thickness
lesions 0-1mm thick: 1cm margin
1-2 mm: 1-2 cm
2-4 mm: 2-3 cm
>4mm: 3 cm
mx of actinic keratoses?
prevention of further risk: e.g. sun avoidance, sun cream
fluorouracil cream: typically a 2 to 3 week course. The skin will become red and inflamed - sometimes topical hydrocortisone is given following fluorouracil to help settle the inflammation
topical diclofenac: may be used for mild AKs. Moderate efficacy but much fewer side-effects
topical imiquimod: trials have shown good efficacy
cryotherapy
curettage and cautery
Which of the following bacteria found on skin is known to contribute to the development of acne?
Propionibacterium acnes
-> tetracyclines, macrolides or trimethoprim must be used in managing acne.
Never tans, always burns (often red hair, freckles, and blue eyes)
skin type?
Fitzpatrick type 1
Black skin (e.g. Afro-Caribbean), never tans, never burns
what skin type?
Fitzpatrick skin type 6 VI
Sunburn and tanning after extreme UV exposure (brown skin, e.g. Indian)
what skin type?
Fitzpatrick type V
Usually tans, always burns
what skin type?
fitzpatrick skin type 2
Always tans, sometimes burns (usually dark hair and brown eyes)
what skin type?
Skin type III
Always tans, rarely burns (olive skin)
what skin type?
Skin type IV
spider naevi associations?
liver disease
pregnancy
combined oral contraceptive pill
when do ppl with burns require IV fluids?
IV fluids should be given in second or third degree burns that cover 15% body surface area or more.
In children, IV fluids are recommended when burns cover 10% body surface area.
Mx of hyperhidrosis?
1st line: Topical aluminium chloride
(main SE= skin irritation)
Iontophoresis
Botulinum toxin
Surgery: e.g. endoscopic transthoracic sympathectomy
(risk of compensatory sweating)
features of lipoma?
benign tumour of adipocytes
smooth, mobile, painless
features suggesting sarcomatous change in a lipoma?
Size >5cm
Increasing size
pain
deep anatomical location
Mx of lipoma?
reassurance, no need for review
can be removed surgically if they are causing symptoms e.g pain, affecting nearby structures like nerves
If features of sarcomatous change (ie size> 5cm) -> US required to rule out liposarcoma
difference between bullous pemphigoid and pemphigus vulgaris in terms of site?
mouth usually spared in bullous pemphigoid
Mx of severe burns?
A->E, senior help
Conservative:
IV fluids required for burns >15% total body surface area (>10% in children)
-> calculate using Parkland formula
Analgesia
Urinary Catheter
May need transfer to burns unit
Surgical:
Escharotomy to divide burnt tissue if respiration impaired/ compartment syndrome and oedema of limb
Excision and skin grafting
Predisposing factors for pityriasis versicolor?
occurs in healthy individuals
immunosuppression
malnutrition
Cushing’s
What drugs are known to induce toxic epidermal necrolysis?
phenytoin
sulphonamides (e.g. sulfasalazine)
allopurinol
penicillins
carbamazepine
NSAIDs
what is the most common malignancy assoc w acanthosis nigricans?
GI adenocarcinoma
what medications are assoc w acanthosis nigricans?
OCP
nicotinic acid
Shingles vaccine
who is offered?
offered to all patients aged 70-79 years*
is live-attenuated and given sub-cutaneously
As it is a live-attenuated vaccine the main contraindications are immunosuppression.
main benefit of giving pts w shingles oral aciclovir?
reduction in the incidence of post-herpetic neuralgia.
What is erythroderma?
used when more than 95% of the skin is involved in a rash of any kind.
Causes of erythroderma?
eczema
psoriasis
drugs e.g. gold
lymphomas, leukaemias
idiopathic
Mx of erythroderma?
monitor for complications like dehydration, infection and high-output heart failure.
tx primary cause
IV fluids
Topical steroids
Antihistamine to help itch
Mx of vitiligo
sun block for affected areas of skin
camouflage make-up
topical corticosteroids may reverse the changes if applied early
there may also be a role for topical tacrolimus and phototherapy, although caution needs to be exercised with light-skinned patients
what viruses may lead to erythema multiforme?
HSV
What bacteria may lead to erythema multiforme?
Streptococcus, mycoplasma
what infection may precipitate guttate psoriasis?
streptococcal infection
excision margins in SCC?
if lesion <20mm in diameter -> 4 mm margin
>20mm -> 6 mm
tx of eczema herpeticum?
admitted to hosp
IV aciclovir
In what pt population is crusted scabies more prevalent in?
immunosuppressed, especially HIV
Tx of crusted scabies?
Ivermectin
isolation is essential
Ix of choice for contact dermatitis?
Skin patch testing
Around 30-40 allergens are placed on the back. Irritants may also be tested for. The patches are removed 48 hours later with the results being read by a dermatologist after a further 48 hours
Ix of choice to determine food allergies, inhaled allergens etc if skin prick not suitable?
ie. extensive eczema or pt taking antihistamines
Radioallergosorbent test (RAST)
Determines the amount of IgE that reacts specifically with suspected or known allergens, for example IgE to egg protein. Results are given in grades from 0 (negative) to 6 (strongly positive)
Ix of choice for food allergies/ pollen?
Skin prick test
Most commonly used test as easy to perform and inexpensive. Drops of diluted allergen are placed on the skin after which the skin is pierced using a needle. A large number of allergens can be tested in one session. Normally includes a histamine (positive) and sterile water (negative) control. A wheal will typically develop if a patient has an allergy. Can be interpreted after 15 minutes
what conditions are assoc w Seborrhoeic dermatitis?
HIV
Parkinson’s disease
Cherry haemangiomas
aka Campbell de Morgan spots
benign skin lesions which contain an abnormal proliferation of capillaries
Features:
erythematous, papular lesions
typically 1-3 mm in size
non-blanching
not found on the mucous membranes
benign -> NO tx required
Oral Leukoplakia
premalignant condition which presents as white, hard spots on the mucous membranes of the mouth
more common in smokers.
Cant be ‘rubbed off’
Biopsies usually performed to exclude alternative diagnoses such as SCC and regular follow-up is required to exclude malignant transformation to SCC, which occurs in around 1%
What type of infection usually precedes pityriasis rosea?
Viral infection
e.g. HHV7
most common side effect of isotretinoin?
dry skin, eyes and lips/ mouth
what is dermatitis herpetiformis caused by?
deposition of IgA in the dermis
- assoc w coeliac disease
Keloid scars vs hypertrophic scars
Keloid scars extend beyond the dimensions of the original wound
Hypertrophic scars do not
Most common sites for keloid scars?
Sternum
Shoulder
Neck
Mx of keloid scars?
early keloids may be treated with intra-lesional steroids e.g. triamcinolone
excision is sometimes required
Strawberry naevus (aka capillary haemangioma)
usually not present at birth but may develop rapidly in the first month of life. They appear as erythematous, raised and multilobed tumours.
Typically they increase in size until around 6-9 months before regressing over the next few years
Common sites include the face, scalp and back. Rarely they may be present in the upper respiratory tract leading to potential airway obstruction
Potential complications of a capillary haemangioma?
mechanical e.g. Obstructing visual fields or airway
bleeding
ulceration
thrombocytopaenia
Tx of capillary haemangioma?
if asymptomatic: no tx required, usually regresses
if tx required e.g. visual field obstruction: propranolol/ topical BB e.g. timolol
what is a pyogenic granuloma assoc w?
trauma
pregnancy
more common in women and young adults
scalp ringworm?
tinea capitis
- cause of scarring alopecia mainly seen in children
cause of scarring alopecia mainly seen in children
fungal infection
Tinea capitis
diagnosis: scalp scrapings, lesions due to Microsporum canis green fluorescence under Wood’s lamp
Mx of tinea capitis?
oral antifungals: terbinafine for Trichophyton tonsurans infections and griseofulvin for Microsporum infections.
Topical ketoconazole shampoo should be given for the first 2 weeks to reduce transmission
well-defined annular, erythematous lesions with pustules and papules
Tinea corporis (ringworm)
causes include Trichophyton rubrum and Trichophyton verrucosum (e.g. From contact with cattle)
may be treated with oral fluconazole
Athletes foot organism?
characteristed by itchy peeling skin between toes
Tinea pedis
common in adolescence
Mx of pressure ulcers?
a moist wound environment encourages ulcer healing. Hydrocolloid dressings and hydrogels may help facilitate this. soap discouraged to avoid drying the wound
consider referral to the tissue viability nurse
surgical debridement may be beneficial for selected wounds
what organism is responsible in the pathophysiology of acne vulgaris?
Propionibacterium acnes
- anaerobic bacterium
initially small red papule
later deep, red, necrotic ulcers with a violaceous border
idiopathic in 50%, may also be seen in inflammatory bowel disease, connective tissue disorders and myeloproliferative disorders
pyoderma gangrenosum
symmetrical, erythematous, tender, nodules which heal without scarring
most common causes are streptococcal infections, sarcoidosis, inflammatory bowel disease and drugs (penicillins, sulphonamides, oral contraceptive pill)
Erythema nodosum
shiny, painless areas of yellow/red skin typically on the shin of diabetics
often associated with telangiectasia
necrobiosis lipoidica diabeticorum
most significant complication of PUVA therapy for psoriasis?
Squamous cell carcinoma
Management of chronic plaque psoriasis?
regular emollients may help to reduce scale loss and reduce pruritus
1st line: potent corticosteroid + vitamin D analogue (calcipotriol) OD (applied separately, one in the morning and the other in the evening) for up to 4 weeks as initial treatment
2nd line: if no improvement after 8 weeks -> vitamin D analogue twice daily
3rd line: if no improvement after 8-12 weeks then offer either: a potent corticosteroid applied twice daily for up to 4 weeks or a coal tar preparation applied once or twice daily
short-acting dithranol can also be used
Tx of choice for Psoriasis in secondary care?
Phototx: narrow band ultraviolet B light (1st line)
Systemic therapy: 1st line oral methotrexate, biologics
Mx of tinea pedis? (athletes foot)
topical imidazole, undecenoate, or terbinafine first-line
2nd line: oral terbinafine
pruritic blistering lesions
often develop in peri-umbilical region, later spreading to the trunk, back, buttocks and arms
usually presents 2nd or 3rd trimester and is rarely seen in the first pregnancy
Pemphigoid gestationis
-> oral corticosteroids are usually required
Skin manifestations of systemic lupus erythematosus (SLE)?
photosensitive ‘butterfly’ rash: usually nasolabial sparing
discoid lupus
alopecia
livedo reticularis: net-like rash
two month history of a rapidly growing lesion on his right forearm. The lesion initially appeared as a red papule but in the last two weeks has become a crater filled centrally with yellow/brown material.
Keratoacanthoma
- benign epithelial tumour
said to look like a volcano or crater
initially a smooth dome-shaped papule
rapidly grows to become a crater centrally-filled with keratin
Mx of Actinic Keratoses?
fluorouracil cream: typically a 2 to 3 week course.
if mild: topical diclofenac
1st line mx of psoriatic plaques?
potent corticosteroid + vitamin D analogue (e.g. calcipotriol)
what is Erythema nodosum?
inflammation of subcut fat
tender, erythmatous, nodular lesions
usually shins, forearms
Immediate first aid of burns caused by heat?
A->E
heat: remove person from source
irrigate burn w cool water for 10-30 min
cover burn with cling film, layered, rather than wrapped around a limb
immediate first aid of electrical burns?
A,B,C
switch off power supply
remove person from source
immediate first aid of chemical burns?
brush off any powder + irrigate w water
attempts to neutralise chemical not recommended
A, B, C
what kind of burn?
skin appears red and painful
first degree
aka
superficial epidermal
what kind of burn?
skin appears pale pink, painful, blistered
partial thickness (superficial dermal) burn
what type of burn?
skin Typically white but may have patches of non-blanching erythema. Reduced sensation
deep dermal, partial thickness burn
what type of burn?
skin is White/brown/black in colour, no blisters, no pain
Full thickness burn
when to refer a burn to secondary care?
all deep dermal and full-thickness burns.
superficial dermal burns of >3% TBSA in adults, or >2% TBSA in children
superficial dermal burns involving the face, hands, feet, perineum, genitalia, or any flexure, or circumferential burns of the limbs, torso, or neck
any inhalation injury
any electrical or chemical burn injury
suspicion of non-accidental injury
mx of superficial dermal burn?
first aid: A-E
refer if >3% in adults, >2% in children or involving face, hands, feet, perineum, genitalia or any flexure
Cleanse wound
leave blister intact
non-adherent dressing
avoid topical creams
review in 24h
Mx of severe burns?
A-E
IV fluids if >10% in children, >15% in adults (Parkland formula)
Urinary catheter inserted
Analgesia
Complex burns -> transfer to burns unit, may require excision and skin grafting
Circumferential burns affecting limb or severe torso burns impeding respiration -> escharotomy
When are escharotomies indicated
circumferential full thickness burns to torso (impeding respiration) or limbs (compartment syndrome, oedema)
Spider naevi vs telangiectasia?
Spider naevia fill from centre
telangiectasia from edge
hirsutism vs hypertrichosis?
hirsutism - androgen dependent hair growth
Hypertrichosis - androgen independent hair growth
most common cause of hirsutism in women?
PCOS
Assessment of hirsutism?
Ferriman-Gallwey scoring system
9 body areas are assigned a score of 0 - 4,
score > 15 = moderate or severe hirsutism
Mx of hirsutism?
weight loss if overweight
cosmetic techniques ie waxing- not avail on NHS
COCP e.g. co-cyprindiol (dianette) or Yasmin (ethinyloestradiol and drospirenone)
facial: topical eflornithine
mx of facial hirsutism?
topical eflornithine
contraindicated in pregnancy and breast feeding
causes of hypertrichosis?
drugs: minoxidil, ciclosporin, diazoxide
congenital hypertrichosis lanuginosa, congenital hypertrichosis terminalis
porphyria cutanea tarda
anorexia nervosa
Abx of choice to treat erythrasma?
oral erythromycin
or topical miconazole
Erythrasma is a generally asymptomatic, flat, slightly scaly, pink or brown rash usually found in the groin or axillae. It is caused by an overgrowth of the diphtheroid Corynebacterium minutissimum
Examination with Wood’s light reveals a coral-red fluorescence.
What factors may exacerbate psoriasis?
trauma
alcohol
drugs: BB, lithium, antimalarials, NSAIDs, ACEi, infliximab
withdrawal of systemic steroids
mx of hyperhidrosis?
1st line: topical aluminium chloride (SE: skin irritation)
iontophoresis: palmar, plantar, axillary
botulinum toxin: axillary
Surgery e.g. endoscopic transthoracic sympathectomy
Yellow nail syndrome?
Improper circulation and drainage of lymph allows fluid to collect in the soft tissue under the skin, which may slowly turn nails yellow.
assoc w lymphoedema
Nail is curved longitudinally and transversely
xerosis = ?
dry skin
ichthyosis?
dry, thickened, scaly skin “fish scale”
inherited skin disorder
needs regular moisturizing
dermatits artefacta?
intentional self inflicted dermatitis
usually odd shapes, straight edges, geometric patterns
straight edges rarely exist in nature -> suggestive of self harm
what is lichen simplex?
localised area of chronic, lichenified eczema/dermatitis.
- a response to the skin being repeatedly scratched or rubbed over a long period of time
- will heal if scratching is stopped
Nodular prurigo?
very itchy firm lumps
- on hands, extensor surfaces
- can be difficult to treat and tends to leave behind scarring
Pompholyx?
aka dyshidrotic eczema
causes tiny blisters to develop across the fingers, palms of the hands and sometimes the soles of the feet.
most common in adults <40
Mycosis fungoides?
a rare form of T cell lymphoma that affects the skin
itchy red papules
lesions tend to be of different colours in comparison to eczema/ psoriasis
