Dermatology Flashcards
Palpable purpura with dots of necrosis around the ankles, what’s it going to be?
Vasculitis
Nails that are splitting down the middle longitudinally are called…?
Oncholysis
GP refers patient who appears to have a symmetrical bilateral fungal infection of one nail on each hand, what is this more likely to be?
Lichen planus
Why does scarring alopecia (hairloss) differ in severity from non-scarring alopecia?
Once scarred, the hair follicles won’t grow back.
In afro-carribbean patients, braiding can cause scarring alopecia
Coin-shaped demarcated patches of hair loss, no signs of scaling or scarring. Diagnosis?
Alopecia areata
Autoimmune response wipes out hair follicles in discrete areas temporarily, but non-scarring
Common causes of scarring alopecia?
IHx?
Lichen planus
Lupus (discoid)
Loosing locks of hair to traction
FoLLicLlitis
IHx: Biopsy scalp- longitudinal and transverse
Immunofluorescence
Nail signs of psoriasis?
Pitting
Oncholysis- nail splitting
Subungal hyperkeratosis- nail pushed up
1st line Rx of psoriasis?
1: emollients
2: topical agents:
steroids
tar
vit D analogues
Who can’t have Acitretin (retinoid) for generalised psoriasis?
Women of child bearing age- teratogenic
The P’s to describe lichen planus?
Purple- 'violaceous' Planar Polished Pigmented- post inflammatory Pruritic- itchier than psoriasis Papular
Nail signs of psoriasis?
Pitting
Oncholysis- nail splitting
Subungal hyperkeratosis- nail pushed up
Who can’t have Acitretin (retinoid) for generalised psoriasis?
Women of child bearing age- teratogenic
Name for tiny bruise under skin?
petechiae
Name for a small and large flat lesion in derm?
Small- macule
Large- patch
Name for a palpable lump in derm, large or small?
Small- papule (0.5cm)
Large- nodule
A patient has noticed a darkened line under their nail, how can you differentiate between a naevi at the nail bed that has grown out with the nail and a melanoma that is spreading underneath it?
The base of the nail takes a year to reach the finger tip end, if the darkened line remains a linear uniform length, it is a nailbed naevi, if it forms a triangle shape then over a year the pigment is getting wider, so its melanoma until proven otherwise.
Risk Factors for skin cancer
Sun exposure
Fair skin
FHx
Phototherapy
Radiotherapy
Immunosuppression
How do dermatologists differentiate between Bowen’s disease (squamous cell cancer in situ) and an isolated psoriatic plaque?
The plaque tends not to respond to steroids if due to cancer, do a biopsy of it.
Pearlescent pink lesion with rolled edges and a ulcerated centre. Name that lesion?
Basal cell carcinoma
Doesn’t metastasise but can infiltrate
What is a lentigo maligna?
Melanoma in situ, often transforms eventually to malignant melanoma
Why are ulcers in a melanoma a bad sign?
Suggests its growing fast enough to necrose
What things determine the prognosis of a melanoma lesion?
Name 4
Breslow thickness (mm > likelihood of dying)
Ulceration
Mitotic rate- histology
Sentinel node biopsy
Management of a mole suspected to be melanoma?
Wide local excision + sentinel node biopsy
If metastatic: use molecular analysis to determine drug
What surgical approach works well for high risk basal cell carcinoma (ones that are recurrent, infiltrative, near eyes/noses/ears etc)?
Mohs surgery- cut out area, look under microscope at tumour margins there and then.
Commonest organism of colonising acne?
Propionibacterium acnes
Rx of mild acne?
Mild comedonal- topical retinoid
Mild pustular- topical retinoid
or benzoyl peroxide + roll on antibiotic
What Rx option is available to women but not men with severe acne?
Anti-androgens
(Co-cyprinderol)
Antagonise androgen receptors
Most important side effect of oral isotretinoin (retinoid for acne)
Retinoid dries skins up
Teratogenic
Have to do a pregnancy test and remind about contraception
Suicide risk
Also: dry skin/lips, hoarse voice, headache, mood swing
Nikolsky’s sign?
When touching the skin near a blister in a patient with pemphigus, the epidermis comes away.
Pemphigus Rx?
Aggressive immunosupression- prednisolone
IV rituximab or immune globulin have big effect
PemphiguS Vs PemphigoiD?
PhemphiguS- Superficial (erosions), more aggressive, epidermis falling apart, fatal without Rx, autoantibodies between individual epidermal cells
PhemiphigoiD- Deep (tense fluid filled blisters), cells can’t attach to basement membrane (due to autoantibodies)
Dermatitis herpetiformis is associated with which GI disease?
Rx?
Coeliac disease
Pruritic symmetrical papules and vesicles
Rx: gluten free diet ± dapsone
Target shaped erythematous rash on hands and feet in a child, has now got red eye and dried lips. Name the syndrome and rash.
Erythema multiforme
Stephen Johnston syndrome
Child is feverish, red, superficial desquamation of the skin.
The cause is infectious, not autoimmune. Diagnosis and organism?
Scolded skin syndrome- staph
Child with itchy scaly annular and serpiginous rash on what hand, what’s the diagnosis?
Tinea corporis- fungal (ring worm)
IHx: microscopy- hyphae of fungus
Which virus is responsible for Kaposi’s sarcoma?
HHV8
Human Herpes Virus 8
Molluscum contagiosum is caused by…?
Pox virus
Gentleman from the philipines, slowly growing pink plaque that is numb. Diagnosis?
Leprosy- can’t feel it when you stick a pin in the plaque
SEs of oral retinoids used in severe acne and how they should be monitored?
Isotretinoin: (reduces sebum production and pituitary hormones)
Teratogenic (pregnancy test) Dry lips + mouth Hepatitis (AST + ALT) High lipids (triacylglycerides + cholesterol) FBC
What type of hypersensitivity mediates allergic contact dermatitis?
Type IV (T cell)
HIV +ve patient has noticed increased dandruff and a red scaly rash over his cheeks.
Diagnosis, cause, Rx?
Seborrhoeic dermatitis
Skin yeast overgrowth (malassezia)
Daktacort, topical ketokonazole or metronidazole
Child is noted to have multiple small blisters and punched out erosions around mouth and neck.
PMH eczema
FHx: mum had a cold sore last few days
Diagnosis, risk, Rx?
Eczema herpeticum:
Primary herpes infection affecting skin already weakened by eczema
Can be life-threatening
Requires aciclovir
Elderly lady has dry scaling red skin that resembles crazy paving on her legs. What is the diagnosis?
Asteatotic eczema
Patient started getting brown pigments on lower legs around the ankles which has developed into dry scaly skin in the area. Diagnosis and Rx?
Venous stasis eczema forms with venous insufficiency where backflow of blood from deep to superficial veins leads to venous hypertension. Brown haemosiderin > oedema > ulceration
Rx: compression stockings to improve venous return but must check ankle brachial pressure index
Name that eczema:
Itchy coin-shaped lesions on legs
Itching vesicles on fingers and palms
Eczema on legs that are swollen with haemosiderin
Coin shaped- discoid eczema
Palmar vesicles- pompholyx eczema
Haemosiderin- venous eczema
Brown greasy warty lesion found in the elderly?
Senorrhoeic keratoses
How can psoriasis be differentiated from discoid eczema?
Psoriasis on extensors, scalp, natal cleft.
Scales are thicker + get silvery on rubbing + bleed on lifting.
Eczema on flexors
What is Köbner’s phenomenon and which conditions does it occur with?
Where the skin disease occurs along trauma lines, where a patient has scratched themselves
Psoriasis, lichen planus, molluscum contagiosum (pink papules)
Systemic causes of pruritis?
Low iron Lymphoma Liver disease CKD Hypo/hyperthyroid Drugs
What is the ABCDE sign for malignancy when it comes to moles?
Asymmetry Border irregularity Colour (non uniform brown, black, blue, red or whites) Diametre >6mm Evolving over time
When excising a dodgy skin lesion what kind of margin is best to aim for?
> 5mm
Diabetic with waxy/shiny pink plaque on shins that turns yellow?
(not ulcerated)
Necrobiosis lipoidica
May be able to see venules where the skin has thinned
Small pustule developed into a large widening ulcer that has a necrotic purple edge on a patients leg. Diagnosis?
Associations?
Pyoderma gangrenosum, autoimmune related- REALLY PURPLE AROUND IT
A: IBD, autoimmune hepatitis, neoplasia, myeloma, wegeners
Autoimmune causes of subcutaneous nodules?
Autoimmune: Rheumatoid nodules, polyarteritis nodosum, sarcoid, granuloma annulare
Infectious: rheumatic fever
Inherited: tuberous sclerosis, neurofibroma
Metabolic: xanthalasma
Causes erythema multiforme?
PSCH
Target lesions, extensor surfaces + palms + soles
Penicillins
Sulphonamides
MyCoplasma
Herpes simplex (70%)
Aside from the vasculitis rash on buttocks in Henoch Schonlein, name 3 other symptoms that might arise
Arthralgia
Abdo pain
Glomerulonephritis
Patient has non-blanching red blue zigzags with normal skin in between like a diamond shaped hole in a net. What is this rash called and causes?
Livedo reticularis Pregnancy, cold RA, SLE, PAN, Raynaud's, polymyositis TB Lymphoma
Rx if erythema migrans is spotted?
Lyme disease- follows a tick bite but >50% won’t recall bite
Doxycycline 3 wkks or amoxicillin 500mg TDS
What are the skin paraneoplastic signs?
Tumour producing GFs > keratinocytes to flourish:
Leser-Trélat sign- sudden flocks of seborrhoeic keratoses
Tripe palms- ridged velvety lesions
Cutaenous papillomatosis
Acanthosis nigricans
Patient has red rings around their eyes, complains of carpal tunnel syndrome, palpitations and neuropathy
You note they have a big tongue. What is the cause?
Amyloidosis
What types of cancer can cause paraneoplastic dermatomyositis?
Lung, breast
Colon, ovary
Helitrope rash, Gottron’s papules (flat violet knuckle papules)
Builder has noticed a crumbly yellow -white scaly crusty lesion on his forehead. What is it likely to be and how can it be treated?
Actinic (solar) keratoses = pre-malignant
Rx:
If suspect squamous cell ca or recurrent- excision
Cryotherapy
Chemical peeling (often reoccurs)
Patient complains of a funny mole on their face. It is like a pearly nodule with a rolled edge. Rx?
Basal cell carcinoma- rodent ulcer
Excision, radiotherapy if big
Cryotherapy if non-visible site
Patient has a slow growing red scaly plaque on their shin, you suspect it is Bowen’s disease. Rx?
= premalignant for squamous cell carcinoma
Cryotherapy Topical fluorouracil (inhibits pyrimidine enzyme) Photodynamic therapy (sensitise + expose)
Pale patch on skin on patient’s back that feels numb. Diagnosis?
Leprosy
Which cancers more commonly metastasise to skin?
Breast, lung, kidney,
Non-Hodgkins lymphoma and leukaemia
Which type of lymphoma manifests in the skin, what is the resultant lesion called?
Mycosis fungoides- T cell lymphoma (only 20% NHL are T cell)
The leukaemic stage is called Sezary syndrome= erythroderma
What are the skin paraneoplastic signs?
Tumour producing GFs > keratinocytes to flourish:
Leser-Trélat sign- sudden flocks of seborrhoeic keratoses
Tripe palms- ridged velvety lesions
Cutaenous papillomatosis
Acanthosis nigricans
Patient complains of a funny mole on their face. It is like a pearly nodule with a rolled edge. Rx?
Basal cell carcinoma- rodent ulcer
Excision, radiotherapy if big
Cryotherapy if non-visible site
Patient has a slow growing red scaly plaque on their shin, you suspect it is Bowen’s disease. Rx?
= premalignant for squamous cell carcinoma
Cryotherapy Topical fluorouracil (inhibits pyrimidine enzyme) Photodynamic therapy (sensitise + expose)
Pale patch on skin on patient’s back that feels numb. Diagnosis?
Leprosy
Which cancers more commonly metastasise to skin?
Breast, lung, kidney,
Non-Hodgkins lymphoma and leukaemia
Which type of lymphoma manifests in the skin, what is the resultant lesion called?
Mycosis fungoides- T cell lymphoma (only 20% NHL are T cell)
The leukaemic stage is called Sezary syndrome= erythroderma
Patient has red cheeks that are worse when she has alcohol or spicy food, her skin is itchy and tender. There is no history of atopy in her PMH or FHx. Likely diagnosis and Rx ladder?
Acne rosacea (erythema, telangiectasis, inflammatory skin lesions)
Rx: topical azelaic acid ± metronidazole
Or doxycycline PO
Which drugs commonly cause patients to have a maculopapular (exanthematous) rash reaction?
Penicillin
Cephalosporins
Anti-epileptics
For which patients is toxic epidermal necrolysis (the bad end of Stephen Johnson syndrom) 1000 x higher?
HIV
Patient has wheals on trunk after taking morphine, she is getting short of breath. Rx?
Anaphylaxis
Antihistamine
IV hydrocortisone
IM adrenaline
Rx for lichen planus?
Topical steroids
May be associated with hep C virus
Which rash starts with one ovoid scaly red patch that precedes the appearance of a number of small red oval patches over the neck, trunk and limbs. Diagnosis + Rx?
Pityriasis rosea
Self limiting
Erythromycin may Rx the rash and reduce the itch
Causes of scarring and non-scarring alopecia?
Scarring: discoid lupus, lichen planus + trauma
Non-scarring:
nutritional (Fe or Zn)
androgenic
autoimmune (alopecia areata/totalis/universalis)
telogen effluvium (shed telogen phase hairs after stress, childbirth, illness, surgery)
Rx for alopecia areata
Steroid injections or topically (limited evidence)
Stinging itchy rash appearing within 30 mins of sun exposure With weals?
Solar Urticaria
Rare
Difference between solar urticaria and polymorphic light eruption?
Both are autoimmune disorders triggered by exposure to sunlight with itchy red papules.
Solar urticaria occurs faster (within 30 mins) and weals are present unlike in polymorphic light eruption (commoner)
A 50 year old woman presents with blisters on the backs of her hands, she has noticed increased hair on her face and hyperpigmentation.
Tests show raised ferritin and LFTs. What other Ihx could you do to confirm the diagnosis?
Porphyria cutanea tarda (lack of uroporphyrinogen decarboxylase in liver needed for RBCs)
IHx: urinary porphyrins (protect from sunlight)
Rx: venesection to lower ferritin, ascorbic acid, chloroquine
Patient has an itchy red scaly nipple. What is the concern and how to exclude it?
Paget’s disease (intraductal breast cancer)
Biopsy to check if it is or if it is eczema
For malignant melanoma excision what margin should be used?
1cm margin for every mm of depth (up to 3cm)
Pathogenesis of psoriasis?
Immune cells activated that activate and recruit T cells
leading to keratinocyte stimulation
and hyperplasia of the epidermis (lack of differentiation)
15 year old patient had tonsilitis bout and then developed multiple red scaly papules over their trunk and legs, which are not itchy. Diagnosis?
Guttate psoriasis
Often presents in the young, with no previous history of psoriasis
What are the different types of psoriasis and their presentation?
Chronic plaque psoriasis (incl palmoplanar psoriasis) symmetrical raised scaly plaques on extensors
Guttate psoriasis- red scaly papules on trunk + peripheries
Pustular psoriasis- erythema, scale, pustules
Erythroderic psoriasis- erythema and scale, head to toe
Rx for mild plaque psoriasis?
- Emollients + soap substitute
- Vit D analogues (slow keratinocyte division)
- Topical steroids
Tar- messy (inpatient)
Dithranol (free radicals in mitochondria slows DNA replication?)
Rx for psoriatic arthritis?
Methotrexate
Infliximab or Etanercept (stops TNF-a activating T cells)
How should Dovobet (vit D analog Calcipotriol + betamethasone) cream be used in stable plaque psoriasis?
Cannot apply it to more than 30% of the body surface
Use only for 4 weeks or less
Repeat if needed after a 4 week break in use
Treatment for moderate psoriasis?
- Phototherapy-
a. narrow UVB (guttate)
b. UVA + psoralen (large plaque) - Topical retinoid (tazarotene)
Rx for severe psoriasis?
HAM
Immunosupression: Methotrexate (avoid in young die to hepatic fibrosis) Ciclosporin Acitretin (oral retinoid) Hydroxycarbamide
Rx for erythrodermic psoriasis?
Ciclosporin or Biological agent (etanercept or ustekinumab)
IV fluids
Greasy emollients
2 treatments for moderate psoriasis?
- Topical retinoid
- Phototherapy-
narrow UVB (guttate)
or UVA + psoralen (large plaque)
Difference between cellulitis and erysipelas?
Erysipelas is infection of upper dermis and superficial lymphatics, lesions are raised above level of surrounding skin and well-demarcated. Ear could be involved (unlike cellulitis).
Strep pyogenes
Cellulitis is infection of deeper dermis and SC fat, less well demarcated ± swelling and pain. Streps ± staphs
Rx of erysipelas?
Erysipelas- strep pyogenes infection of upper epidermis, raised and red and well-demarcated
Penicillin
Rx for cellulitis?
Cover streps- Benzylpenicillin IV
And staphs- flucloxacillin PO
Causes of erythema nodosum?
PBS
Penicillin, pregnancy, Pill
tB, iBd, Behcet’s
Strep, Sarcoid, sulphonamides
How does TB present in the skin?
Lupus vulgaris- crusted red-brown patch IHx like apple jelly when pressure is applied with a glass slide Scrofuloderma- suppurating nodules TB verrucosa cutis- warty plaques TB gumma- nodules turn into ulcers Tuberculids- crops of lesions
Cause and Rx for hand warts?
Cause: human papillomavirus
Rx:
1. Salicylic acid
kills keratinocytes containing the wart virus (HPV
2. Cryotherapy
Management of genital warts?
Cryo + Podophyllin (teratogenic)
Or Imiquimod cream
Screen for STIs
If child- suspect abuse
What do molluscum contagiosum look like?
What is the cause and associated conditions?
Shiny smooth pink papules, may have a depressed punctum
Cause: Pox virus
A: atopic eczema, HIV
Rx options for shingles and their side-effects
Mild: one
Severe/immunocompromised:
Aciclovir (Confusion, LFTs up, GFR down)
Fanciclovir. (Confusion, headache)
Prophylaxis if exposed and immunocompromised: immune globulin + zoster vaccine
Which drugs cause photosensitivity?
ANTTT
Amiodarone NSAIDs Thiazides Tetracyclines Tricyclics
Difference between venous and arterial ulcers?
Venous- medial malleolus, with associated skin changes (lipodermatosclerosis)
Rx: compression to improve venous return
Arterial- punched out ulcers on shin, toes, dorsum of foot
Rx: vessel grafting
Patient has an ulcer on their medial leg, what IHx is needed before Rx?
ABPI, if
After how long would you consider biopsying a leg ulcer if it failed to heal and why?
3 months, could it be cancer?
What blood tests could help you exclude different causes of pruritus in the elderly?
FBC- anaemia, polycythaemia
LFT- liver failure
U+E- renal failure
TFTs- thyroid up or down
Others: biopsy (pemphigoid), EHx (eczema, solid cancer), lymphoma
How are pressure sores staged?
Stage 1: non blanching erythema over intact skin
Stage 2: partial thickness skin loss (shallow crater)
Stage 3: full thickness skin loss extending into fat
Stage 4: destruction of muscle, bone or tendons
HIV +ve patient has come in with an extensive scaly crusty rash over their arms. Their HIV +ve partner has also started getting it. What is it and rx?
Scabies (mite)
Permethrin- insecticide
Ivermectin
HIV +ve patient has had these really itchy papules and pustules, what IHx would you do and what what could it be?
Skin biopsy
Eosinophilic folliculitis
Rx:
- tacrolimus
- steroids
- UV therapy
Rx for Kaposi’s sarcoma in HIV population?
HAART
radiotherapy (palliative)
IFN-a (antiviral for HHV-8)
Rx of oral hairy leukoplakia
Podophyllum + aciclovir (against epstein barr virus)
A patient complains of itchy red penile papules, he’s noticed some itchy red rash in the web spaces of his fingers. For the likely diagnosis what test should be sent and what would you expect to find on examination?
Scabies
EHx: burrows in skin, with black dot
Microscopy: skin scraping for eggs or mites
Rx: Permethrin to all skin from neck down, including soles
Darier’s sign?
In mastocytosis (urticaria pigmentosa) too many mast cells in skin = brown macules which become more itchy swollen and red if rubbed or scratched.
Such patients also get headache, flushing, palpitations, wheeze etc
Causes for arterial or venous leg ulcers?
Venous: DVTs and ageing lead to valvular incompetence, leading to varicose veins and venous hypertension as blood backs up and dilates superficial veins. Inflammation leads to skin break down and ulceration.
Arterial: atherosclerosis + diabetes obstructs blood flow leading to ischaemia and cell necrosis
Name for moderate bruise under the skin?
Purpura
Name for large bruise under the skin
Eccymoses
Infectious cause of subcutaneous nodules?
Infectious: rheumatic fever
Autoimmune: Rheumatoid nodules, polyarteritis nodosum, sarcoid, granuloma annulare
Inherited: tuberous sclerosis, neurofibroma
Metabolic: xanthalasma
Inherited causes of subcutaneous nodules?
Inherited: tuberous sclerosis, neurofibroma
Autoimmune: Rheumatoid nodules, polyarteritis nodosum, sarcoid, granuloma annulare
Infectious: rheumatic fever
Metabolic: xanthalasma
What derm things are diabetics susceptible to?
Necrobiosis lipoidica,
Flexural candidiasis
Folliculitis
Arterial insufficiency - ulcers
What is the difference between pyoderma gangrenosum and necrotizing fasciitis?
Both have ulceration + necrosis
NF is a life-threatening infection Rx: debridement and Abx
PG is auto-inflammatory condition associated with IBD + arthritis Rx: steroids
Sudden flocks of subhorreic keratoses on the body is a sign of?
What is this sign known as?
Paraneoplastic phenomena
Leser-Trelat sign (due to GH secretion)
Visible signs of dermatomyositis?
Helitrope rash
Gottron’s papules (flat violet knuckle papules)
systemic Rx for psoriasis?
- retinoids
- hydroxycarbamide stop T cells
- biological agents (anti-TNF)
What defines acne as severe?
Presence of nodules, cysts, scarring
Difference between actinic keratosis and Bowen’s disease?
Both are pre-malignant for squamous cell Ca.
Bowen’s spreads through full epidermis, may spread laterally.
Actinic keratosis maintains squamous differentiation, is smaller and on sun-damaged skin only
Pre-malignant lesions for melanoma and squamous cell Ca?
Melanoma- lentigo maligna
Squamous Ca- actinic keratosis then Bowen’s disease
How does xeroderma pigmentosa present?
Severe sunburn on first exposure to sunlight
Eyes very sensitive to sun, become irritated and bloodshot easily
Blistering and freckling
(Due to auto R defect in nucleotide excision repair genes)
Difference between acne rosea and pityriasis rosacea?
Pityriasis- herald patch (?viral), and found on the trunk, self limiting
Rosacea- inflammatory reddening with alcohol, spice, azelaic acid ± metronidazole
What is the genetic defect causing xeroderma pigmentosa and it’s inheritance?
Autosomal recessive
Defect in nucleotide excision repair enzymes
Who is at risk of developing pellagra? (Red scaly rash occurring on areas of sun exposure)
Pellagra = niacin deficiency (Vit B3)
Diarrhoea, dermatitis, dementia
RF nutritional deficiency: alcoholics
Isoniazid or 5-fluorouracil users
Itchy vesicles on elbows, knees and buttocks in a 40 year old man?
Dermatitis herpetiformis
1 year old baby has started crawling and gets blisters on knees and elbows that heal without scarring. What could be the cause?
Epidermolysis bullosa- autosomal dominant
How does intraventricular haemorrhage typically present?
Sudden deterioration in week 1
Or altered level of consciousness, hypotonia, reduced movements or respiratory function
How do IHx differ for an acute neurovisceral type of porphyria compared to a chronic cutaenous porphyria?
Acute Neurovisceral: Urine PBG
Chronic blistering cutaenous: plasma or urine porphyrins
How do you estimate the proportion of the body that is burnt?
Wallace's rule of 9's, 9% assigned to: Head and neck, Each arm, Anterior leg, Posterior leg Anterior chest, Posterior chest Anterior abdomen, Posterior abdomen
How do IHx differ for an acute neurovisceral type of porphyria compared to a chronic cutaenous porphyria?
Acute Neurovisceral: Urine PBG (porphobilinogen)
Chronic blistering cutaenous: plasma or urine porphyrins
In partial thickness burns, how can you tell if it is a superficial or deep dermal burn?
Superficial dermal, pink + painful + blistered
Deep dermal, white + some erythema + reduced sensation
Rx for granuloma annulare (raised skin-coloured plaque with rolled nodular edge)
Topical steroid
Emollient + soap substitute
Intralesional steroid injection
Phototherapy
Systemic= methotrexate if generalised
3 types of basal cell carcinoma?
Nodular- (classic, head + neck)
Superficial- (trunk, pink patch)
Morphoeic = poorly defined
Rx: Moh’s micrographic surgery
Conservative: radiotherapy
Conservative superficial: Cryo, 5-FU, Imiquimod
Patient has itchy purple scaly papules on foot dorsum, confluent in places, lichen planus or psoriasis?
Lichen planus = itchy
Rx:
- emollient
- Super potent topical steroids
- Phototherapy
How to differentiate acne vs rosacea?
Acne- comedones (blackheads)
Rosacea- no comedones
(May also have telangiectasia)
1st class of antibiotics PO given in acne?
Tetracyclines for 3 months
Rx for acne rosacea?
1.Metronidazole
- Oral tetracycline
- Oral retinoid
widespread purple patches on lower limbs with some central ulceration is characteristic of…
vasculitis
2 things to rule out before contacting derm (secondary causes):
- Check drug chart for new drugs
- Sepsis
In a cutaenous vasculitic purpuric rash what needs to be checked first before dealing with the dermatological side?
Any systemic effects of vasculitis
Check kidney function: U+Es, BP
Superficial punched-out ‘scolded-looking’ ulcer with purple overhanging edge and papular pustules on other leg. No stigmata of arterial disease. Differential?
Pyoderma gangrenosum
Differential: vasculitic ulcer, arterial ulcer
Biopsy
In malignant melanoma how do you decide whether to do a sentinel lymph node or not?
If it has a Breslow thickness greater than 1mm
Desquamation is defined by?
How do you know the epidermis hasn’t been removed?
Loss of stratum corneum (staphs > scolded skin syndrome)
No bleeding
Brown birth mark (that is a symmetrical macule) is described clinically as?
Congenital melanocytic naevus
Toxic epidermis necrolysis vs scolded skin syndrome- what is the difference?
Mucosa involvement = TEN
What defines a rash as erythrodermic?
If rash is covering more than 95% of body surface area
4 causes of erythroderma?
Drug reactions
Eczema, Psoriasis
Cutaneous lymphoma
Describing eczema on the face of a baby?
Symmetrical ill-defined erythematous patches with excoriation
Pros and cons of different actinic keratosis treatment?
Liquid nitrogen: leaves hypopigmented skin
5-Fluorouracil: better for young patients, less after-scar
‘Ring of pearls’ widespread blisters are characteristic of?
Ring of pearls= linear or circles or blisters
Linear IgA bullous disease
Occurs in children
On observation, what indicates if alopecia is scarring or non-scarring?
Visible follicles = non-scarring
In derm terms, vitiligo can be described as
Irregular macular hypopigmentation
What lifestyle choice is associated with palmo-planar pustular psoriasis?
Smoking
Try to convince them to quit
Difference between discoid lupus and systemic lupus?
Discoid lupus is scarring, other manifestations of lupus may not be.
Both are “photo-distributed”- in sun exposed areas, check skin creases and under the eyes for sparing.
Kids with boggy abscesses (blistering nodules) on the scalp?
Kerion- fungal (on the tinea spectrum)
Treat family also.
Griseofulvan or Itraconazole
What sign do dermatofibromas show?
Tent sign: if you pull the skin taught, they pull the skin in with them
Dermatofibromas are typically scar tissue formed from a previous insect bite, just reassure patient
Old lady has what looks like a shiny pale pink scar on her face as if the skin has been cut away, but she’s never had surgery. What is the diagnosis?
Morphoeic basal cell carcinoma
Difference between gas gangrene and necrotising fasciitis?
Gas gangrene- clostridium perfringens, often encountered in soil. Gas formation is felt as crackling under the skin
Nec Fasc- strep or pseudomonas
Tests needed when starting roaccutane (isotretinoin) for acne?
AST, ALT, triglycerides, cholesterol, FBC
Tests needed when starting oral retinoid- acetretin for psoriasis (NB this is a different drug to roaccutane)?
Lipids, glucose, LFTs
May all be raised by the drug
What is responsible for leprosy disease?
Mycobacterium leprae _ lepromatosis
= granulomas in the nerves, respiratory tract, skin and eyes