Derm Flashcards
A 7-month-old boy is brought to the emergency department by his family. He has a history of eczema, which is usually well-controlled, and previous chickenpox. Over the last 5 days, he has developed a worsening rash. This started with clusters of blisters on the face and neck. These have now spread to the trunk and arms.
You find a symmetrical monomorphic eruption of small blisters with central umbilication. They are filled with yellow fluid and blood-stained. The skin surrounding these clusters is normal. The patient is febrile and lethargic.
What is the most likely causative organism?
herpes simplex virus
the boy has eczema herpeticum
Common features of eczema herpeticum
- symmetrical
- clusters of blisters
- fever
- malaise
- central umbilication
How would the following infections present in children:
- staph aureus:
- strep pyogenes:
- trichophyton rubrun:
- VZV:
- staph aureus: staphylococcal scalded skin syndrome, wrinkled skin, large, fluid-filled blisters, generalised exfoliatibe dermaitits
- strep pyogenes: impetigo
- trichophyton rubrun: tinea corporis, single circular patch with erythema and scaling, would not be too widespread
- VZV: chickenpox/shingles
tx for children with eczema herpetricum
IV aciclovir
tx for children with new onset purpura
referred immediately for investigations to exclude ALL and meningococcal disease
petechiae vs purpura - which is a common finding in children
petechiae can be seen in a viral illness or with increased superior vena cava pressure (e.g. following a cough)
purpura are never a normal finding in children
which drugs can cause purpura in adults?
quinine, antiepileptics, antithrombotics
_____ in a contraindication to topical AND oral retinoid tx
pregnancy
tetracyclines should be avoided in____________
pregnant or breastfeeding women and in children younger than 12 years of age
for acne, __________________________ should always be co-prescribed with oral antibiotics to reduce the risk of antibiotic resistance developing
a topical retinoid (if not contraindicated) or benzoyl peroxide
for acne, gram-negative folliculitis can develop if you use long term abx. Treat with ______
high-dose trimethoprim
A 16-year-old girl presents to the GP with swollen lips and a tingling sensation in her mouth, accompanied by small red raised spots around her mouth. She reports that these symptoms began approximately two hours after consuming shrimp. She has no known allergies and has not previously experienced similar symptoms. The patient denies experiencing any difficulty breathing or swallowing.
What does she have? Whats the frst line tx?
urticaria ( swelling and wheals confined to the oral region following an allergic reaction)
course of oral loratidine/cetirizine (non-sedating, unlike say chlorpheniramine)
tx for severe/resistant ultricaria
prednisolone alongside antihistamines
A 30-year-old female in her third trimester of pregnancy mentions during an antenatal appointment that she has noticed an itchy rash around her umbilicus. This is her second pregnancy and she had no similar problems in her first pregnancy. Examination reveals blistering lesions in the peri-umbilical region and on her arms. What is the likely diagnosis?
Pemphigoid gestationis - pruritic blistering lesions, develop in peri-umbilical regions, spread to trunk, back, buttocks and arms.
- 2nd/3rd trimester
- tx with oral corticosteroids
A 54-year-old woman presents to her general practitioner with a rash affecting her cheeks, nose, and forehead. The rash is worse when exposed to the sun. She has no past medical history.
On examination, there is an erythematous rash affecting her nose, cheeks, and forehead diffusely and involving the nasolabial folds. There is a minimal amount of papules and pustules visible.
what is the Dx?
Rosacea
Tx for rosacea
mild/moderate: topical ivermectin
severe/resistant: combination of topical ivermectin + oral doxycycline
name of phenomenon new leseions develop on previously unaffected skin after trauma/chemial irritation
koebner phenomenon
A 56-year-old gentleman presents to the dermatology clinic. Over the last few weeks, he has noticed a new, enlarging lesion on his cheek which sometimes bleeds. On examination, he has Fitzpatrick skin type I, multiple melanocytic naevi over his body, and the lesion in question is a large, black, dome-shaped lump, of 1cm diameter, located on his right cheek. What is this lesion most likely to represent?
Nodular melanoma: Red or black lump, oozes or bleeds, sun-exposed skin
- tx with amoxicllin
- widepsread erythematous bullae and vesicles
- lesions in oral muscoa and eyes
- Nikolskys sign positive
What is the Dx?
topical epidermal necrolysis
nectrotising fasciitis often starts as _____
localised cellulitis that then spreads
skin overlying infection can appear tinged grey
drugs known to produce TEN
phenytoin
sulphonamides
allopurinol
penicillins
carbamazepine
NSAIDs
SNAPAC
A 10-year-old child is admitted with severe 30% burns following a house fire. After wound cleaning and dressings he is admitted to critical care. 1 day following skin grafts he becomes tachycardic and hypotensive. He vomits twice and this shows evidence of haematemesis
Dx?
Curlings ulcer - stress ulcers that occur in the duodenum of burns patients
Eletcrical high voltage burns are associated with _________. Tx with aggressive IV fluid resuscitation.
rhabodmyolysis
A 45-year-old man is admitted after his clothing caught fire. He suffers a full thickness circumferential burn to his lower thigh. He complains of increasing pain in lower leg and on examination there is parasthesia and severe pain in the lower leg. Foot pulses are normal
Dx?
Compartment syndrome as burns have constricted the limb, perform eshcarotomy
Which condition is associated with each of these pathophysiological processes?
- release of epidermal toxins A and B:
- release of igE from plasma cells:
- formation of igA antibodies:
- latent reactivation of herpes zoster virus:
- release of histamine from mast cells:
- release of epidermal toxins A and B: SSSS
- release of igE from plasma cells: atopic dermatitis
- formation of igA antibodies: dermatitis herpetiformis
- latent reactivation of herpes zoster virus: shingles
- release of histamine from mast cells: urticaria
which drug is known to exacerbate plaque psoriais?
betablockers, NSAIDs, lithium, antimalarials
plaque:
- propanolol (BB)
- lithium
- aspirin (NSAID)/ACEI
- quinine (antimalarial)
- eliminating steroids
On examination, there are multiple clusters of well-demarcated papules, around 0.5cm in diameter, with an umbilicated centre over the trunk and face. The child seems settled and his mother reports no recent change in behaviour.
Dx?
Molluscum contagiosum caused by poxvirus
Scabies tx
In scabies, advise all close contacts to be treated as well as the patient twice, with applications one week apart
2 doses of permethrin cream
Tx for crusted scabies
in those with suppressed immunity, especially HIV
ivermectin
Shingles - paracetamol, ibuprofen, codeine and amitriptyline are all not helping. What do you add for refractory pain?
Corticosteroids (prednisolone)
In people over 50, well-circumscribed plaques or papules with a ‘stuck on’ appearance, and most commonly affect the torso or face. The colour of the lesions can vary, but they are most commonly grey-brown or black. Typically the lesions are asymptomatic.
Dx?
Seborrhoeic keratosis
Combination of thrombocytopenia + prolonged APTT, with background of recurrent DVTs, suggest ________.
Common skin findinging in pts with this condition:
antiphospholipid syndrome
livedo reticularis: purplish, lace-patterened discolouration
Which condition is each of these examination findings associated with:
- fine scale over both knees:
- multiple target lesions:
- single large target lesion with raised edge:
- tender red nodules on anterior shins:
- fine scale over both knees: psoriasis
- multiple target lesions: erythema multiforme
- single large target lesion with raised edge: erythema migrans (Lyme disease)
- tender red nodules on anterior shins: erythema nodusum
what can be used to reduce redness in roacea?
brimonidine
for paples/pustules: ivermectin, azelaic acid
what is ertyhema multiforme characterised by? what are the causes?
multiple target lesions
Epileptic (carmbamazepine)
R
Y
T
HSV
E
M
Allopurinol
Mycoplasma, strep
U
L
T
I
F
O
R
M
E
what skin malignancy can you develop after renal transplant?
squamous cell carcinoma of the skin
1st line tx for lichen planus
topical steroids
‘Inside the mouth, the patient has white striae on the oral mucosa’ - what is this?
Wicham striae, indicative of lichen planus
Tx for facial hisutism
Topical eflornithine
Nail infection:
1. tx if mild fungal nail infction positive for dermatophytes/candida:
- tx if more than 2 nails affected:
- tx if mild fungal nail infction positive for dermatophytes/candida: topical amorolfine
- tx if more than 2 nails affected: oral antigungal like itrconazole
_________- is used to calculate the volume of IV fluid required for resuscitation over the first 24 hours after the burn
Parkland formula
lesion on the face of an old person that looks like a volcano/crater, centrally-filled with keratin
keratoacanthoma, fast-tracked to exclude SCC
‘On examination she has a very fine layer of soft un-pigmented hair that covers her entire body, apart from her palmar and plantar surfaces.’ - what is the most likely cause?
lanugo hair, malnutrition
Red, scaly patches in elderly patients, slow-growing, on sun-exposed areas. Dx an Tx?
Dx: bowen’s disease, precancerous dermatosis
Tx: topical 5-fluorouracil, excision
This is a condition that manifests as an erythematous eruption of small papules and papulopustules with distribution primarily around the mouth. The rash does not affect the lips, hence sparing of the lip border is typical.
Dx? What can make it worse?
perioral dermatitis
topical steroids
______ commonly exacerbates chronic plaque psoriasis
lithium
A one-year-old child presents to the GP with his mother for his vaccinations. His mother is pleased to note that his birthmark, which was a pink flat mark on his eyelids and on the nape of his neck has almost faded entirely.
What is the most likely birthmark this child has?
salmon patches
portwine stain does not disappear over time
arterious vs venous ulcer - difference in presentation
arterious:
- burning pain in leg
- ulceration over bony promiences
- punched out ulcer appearance
- T2DM, smoking
venous:
- aching lower limb
night cramps, cramps after sitting
- relief upon leg elevation
- skin discolouration, stasis eczema
A 31-year-old female attends her general practice due to the presence of multiple red lesions on her shins which have developed over 48 hours and are painful.
Dx? Causative drugs?
erythema nodusum
penicillins
sulfonamides (sulfasalazine)
COCP
pregnancy
lesion that starts as blister, then skin breaks down and becomes ulcerated. Ulcer can be deep and necrotic with purple edges. Lesion usually on lower limb. Background of IBD/SLE/RA/myeloprolierative disorders.
Dx? Tx?
Pyoderma gangrenosum
1st line: oral steroids
1st line tx for hyperhidrosis
topical aluminium chloride
pre-malignant skin lesion that develops as a consequence of chronic sun exposure, featuring small, crusty, scaly lesions. More common in the elderly. Dx and Tx?
Dx: actinic keratoses
Tx: fluorouracil cream, topical hydrocortisone, diclofenac, imiquimod
The clinical presentation of an itchy scalp, dandruff, and eczema on the scalp, behind the ears, and around the nose suggests a diagnosis of_______. Tx with _______.
seborrhoeic dermatitis
topical ketoconazole
The rash usually starts with a single, larger pink or red oval patch (herald patch) and then smaller patches appear on the body, often in a ‘Christmas tree’ pattern.
Dx? How long does the rash last? Tx?
Pityriasis rosea
6-12 weeks
self-limiting
Melanoma:________ is the single most important prognostic factor
the invasion depth of the tumour
Severe urticaria - _______________ may required in addition to a non-sedating antihistamine
A short course of an oral corticosteroid
Clindamycin treatment is associated with a high risk of Clindamycin treatment is associated with a high risk of C. difficile
Clindamycin treatment is associated with a high risk of C. difficile
woman has pink/purple papules over wrist, no lesions anywhere else, no skin changes in web spaces and no burrow lesions - Dx? Tx?
- lichen planus
-topical betamethasone 0.1% (potent)
steroid strength - way to remember
‘Helps Every Budding Dermatologist’:
Helps - Hydrocortisone 1% - Mild.
Every - Eumovate (clobetasone butyrate 0.05%) - Moderate.
Budding - Betnovate (betamethasone valerate 0.1%) - Potent.
Dermatologist - Dermovate (Clobetasol propionate 0.05%) - Very potent.
causes of erythema nodusum
NO – idiopathic
D – drugs (penicillin sulphonamides)
O – oral contraceptive/pregnancy
S – sarcoidosis/TB
U – ulcerative colitis/Crohn’s disease/Behçet’s disease
M – microbiology (streptococcus, mycoplasma, EBV and more)
fungal nail infection on more than 2 nails - tx?
oral terbinafine
_________ may be a useful treatment for keloid scarring
Intra-lesional steroids
[ skin disease] may be associated with GI malignancies such as gastric and pancreatic cancer.
deeply jaundicecd, dark velvety lesion on tongue
Acanthosis nigricans
what are acanthosis nigricans associated with?
- T2DM
- GI cancer
- obesity
- PCOS
- acromgelay, cushings
___________ is a common premalignant skin lesion that develops as a consequence of chronic sun exposure. Tx _______
acitinic keratoses
topical imiquimod
1st line for athlete’s foot
topical imidazole, terbinafine**
______________ - severe primary infection commonly seen in children with atopic eczema. Presents as rapidly progressing painful rash. Tx?
Eczema herpeticum - infection with herpes simplex virus 1 or 2
Tx w aciclovir
target lesions + preceding viral/bacterial infection =
erythema multiforme
where does erythema nodusum commonly manifest? What systemic diseases is it associated with?
Shins
Sarcoidosis, IBD, behcet’s
strep infection 2-4 weeks before + tear drop papules on trunk and limbs =
guttate psoriasis
epistaxis + telangiectases + visceral lesions + positive FHx =
hereditary haemorrhagic telangiectasia (AD)
tx for facial hirstuisim
topical eflornithine
______________________ is the single most important factor in determining prognosis of patients with malignant melanoma
The invasion depth of a tumour (Breslow depth)
vitamin B3 is
nicotinic acid!
3Ds of pellagra
pellagra = nicotinic acid deficiency
3 Ds: dermaititis, diarrhoea, dementia
___________ presents with a herald patch and is associated with a ___________ appearance
pityriasis rosea
fir tree
oral Tx for psoriasis?
methotrexate
pityriasis rosea Tx?
none, self-limiting
may cause a mild itch, in which case topical steroids and oral antihistamines could be considered
rash on arms and legs associated with pregnancy?
erythema nodosum
1st line Tx for pyoderma gangrenosum?
oral steroids
1st line for perioral dermatitis?
doxycycline
Use SSSSTT for the erythema diseases (works for e. multiform too, just sub sulphonamide for SLE)
Streptococci infection (!!!)
Sarcoidosis/ Systemic disease (e.g. IBD)
Sarcoidosis = non-caseating granulomas in lungs/lymph nodes)
Sex => Pregnancy + COCP
Sulphonamide
Tuberculosis (!!!)
Tumour/ lymphoma
SSSSTT
