MedEd Flashcards
A 1-year-old boy is brought to the GP clinic with a dry, scaly, erythematous rash on his cheeks and chin. He appears systemically well, and is not crying, however he repeatedly tries to move his hand to the rash. On close inspection of the rash, you also notice some small excoriation marks. The rash is limited to the face, with no spread to the limbs or trunk. On questioning, the father suffers from asthma. Select the likely diagnosis:
Parvovirus B19 infection Atopic dermatitis Plaque psoriasis Contact dermatitis Impetigo
Atopic dermatitis
A 22-year-old woman presents to her GP complaining of a moderately itchy rash present on both arms. She is systemically well. The rash is plaque-like in appearance, with well-defined edges and a silvery surface, present on the extensor surfaces of both elbows. She reports also noting a scaly, itchy rash on her scalp. Which of the following is not associated with this disease:
Arthritic pain Onycholysis Nail pitting Family history of asthma Rashes on the palms and soles
Family history of asthma
A 78 year old diabetic woman with a history of poorly-healing leg ulcers presents to her GP with a painful skin rash, following a 5-day course of topical antibiotic treatment for a skin infection. The rash appears blistered, with several vesicles present over the site of the previous skin infection, some of which have burst on examination, releasing clear fluid. The patient moans that the drug didn’t clear her infection. What is the likely diagnosis?
Erythema multiforme Pemphigus Secondary infection with S. aureus Allergic contact dermatitis Irritant contact dermatitis
Allergic contact dermatitis
what protein is decreased in atopic dermatitis
fillagrin
what is fillagrin
a protein responsible for keeping moisture in the stratum corneum and for maintaining the skins slightly acidic pH
what sort of hypersensitivity reaction is associated with atopic dermatitis
type I (immediate hypersensitivity with igE)
what sort of condition is psoriasis
immune-mediated inflammatory condition
who does psoriasis commonly affect
young adults
which inflammatory cytokines are associated with psoriasis
Il-1B, TNF-a, IL-17a
what are features of plaque psoriasis
symmetrical scaly plaques which are salmon pink with silver scales
where is plaque psoriasis commonly found
extensor surfaces
what are features of guttate psoriasis
“gutta” means teardrop
small red scaly ‘teardrops’ across the body
commonly following a URTI with strep
what is erythroderma
dry red skin across the body
what are triggers for erythrodermic psoriasis
drugs (anti-malarias, lithium, BBs), infections, low calcium, cessation of steroids
what is the treatment for erythrodermic psoriasis
hospitalisation
IV fluids, temp regulation, emollients
what sort of hypersensitivity reaction is allergic contact dermatitis
type IV (delayed)
what is characteristic of parvovirus B19
‘slapped cheek’ rash and also causes red cell aplasia
what is red cell aplasia
erythrocytes stop maturing - causes normocytic anaemia
what is pemphigus
a bullous disease where large bullae result from separation of epidermis from the dermis
what sort of condition is pemphigus
autoimmune
A 65 year old man presents with what he describes as a strange lump on the side of his nose. He says he first noticed it 4 months ago, but didn’t go to his GP as he spends 6 months of the year in the Cayman islands where his tax-free earnings live. You notice he has many freckles on his face and chest. The lump is a skin-coloured, round, well-circumscribed nodule with rolled edges and a pearly appearance, and blood vessels crossing its surface. Select the likely diagnosis:
Basal cell carcinoma Fluid-filled cyst Keratoacanthoma Malignant melanoma Squamous cell carcinoma
Basal cell carcinoma
A 55-year old Australian man attends your dermatology clinic worried about a mole on his back. He says his wife spotted it when on the beach, and that it appears bigger than when she first noticed it 6 weeks ago. Upon examining his back, you notice more than 10 moles. The mole of concern is different to the others, as it has irregular, poorly-circumscribed edges and variable pigmentation, and is considerably larger than its siblings. Its appearance under the dermatoscope worries you. Select the most appropriate next step:
Immunohistochemical staining Ultrasound scan Partial biopsy Total excision 5-fluorouracil cream
Total excision
A 68 year old man with a history of previous BCC comes to your GP rapid access clinic, concerned about a sudden growth on his right ear. He says it started less than two weeks ago as a small pimple, which he tried to pop but couldn’t, and is now the size of an olive (2cm). The nodule is spherical, skin coloured and ulcerated, with a scaly core. Select the likely diagnosis:
Rapidly growing BCC Keratoacanthoma Bowen’s disease HPV-induced wart Squamous cell carcinoma
Keratoacanthoma
A 75 year old woman with a history of topically-treated solar keratoses (scaly sun spots) comes to your GP surgery looking intensely worried. Over the past 8 weeks she has noticed a “horn” growing from the skin at the front of her scalp. The horn is yellow-brown in colour, crusty in appearance, approximately 10mm in height and 5mm in width. The skin at the base is red and indurated. Her persistent concern is that she is turning into a goat. You assure her this is not the case. You also consider a referral to Psych. Select the likely diagnosis:
Keratoacanthoma Bowen’s Disease Malignant melanoma Squamous cell carcinoma Osteocarcinoma She is actually becoming a goat
Squamous cell carcinoma
where are squamous cells in the skin found
outer layer of the epidermis
what are features of BCC
shiny pearly nodule with rolled edges and central ulceration
there may be a blood vessel in the middle
how quickly does a BCC grow
slowly
pathogenesis of BCC
mutation in PTCH1 tumour suppressor gene which inhibits sonic hedgehog signalling cascade
what is the most common malignant melanoma
superficial MM
what are features of malignant melanoma
Asymmetry Borders (irregular) Colour variation Diameter >6mm Evolution
how is MM diagnosed
dermatoscope: finds suspicious lesion
excision of lesion plus 2-3mm of margins
pathological diagnosis
how is MM staged
breslow thickness which measures melanoma depth from granular layer to deepest point of tumour
what are features of SCC
enlarging scaly of encrusted lumps formed of keratin
what is cutaneous horn SCC
an outgrowth of keratin in SCC like a horn
pathogenesis of SCC
p53 mutation
what form of SCC rapidly progresses and rapidly regresses
keratoacanthoma
what differentiates keratoacanthoma and true, lethal SCC
keratoacanthoma progresses very rapidly
is keratacanthoma benign or malignant
benign (however all other SCCs are malignant)
A 28-year-old woman attends her GP with a 1 month history of diarrhoea, which is associated with right lower quadrant pain and mucus in the stool. She reports no blood in stool, but is feeling increasingly tired, which she feels is due to her waking up 3-4 times per night to go to the toilet. She also reports having incredibly painful, red lumps on the front of her leg, which are tender to touch, inflamed and non-ulcerated, with the skin intact. What is this likely to be?
Pyoderma gangrenosum Purpura Dermatitis herpetiformis Erythema nodosum Venous ulcer
Erythema nodosum
what are erythema nodosum
a form of panniculitis (inflammation affecting subcutaneous fat)
where does EN commonly occur
shins
who is EN common in
women
what is pyoderma gangrenosum
autinflammatory condition due to neutrophil dysfunction
what condition is both EN and pyoderma gangrenosum associated with
IBD
what is characteristic of the ulcer in pyoderma gangrenosum
edge of ulcer is purple and undermined
what is dermatitis herpetiformis associated with
coeliacs disease
A 49-year old woman presents to her GP with a rash on the back of her hands and feet, which has been there for about 2 days and is concerning her. The lesion are papular (raised), circular, well-defined, erythematous target lesions, and their spread is confined to the dorsum of her hands and feet. She says she has been feeling well, and her only over-the-counter medicine used in the past 2 weeks is some acyclovir for a cold-sore on her lip. When asked, she said she noticed the rash soon after the cold-sore. Select the likely diagnosis:
Stevens-Johnson Syndrome Erythema multiforme Urticaria Cellulitis Post-viral fever rash
Erythema multiforme
what are target lesions common in
erythema multiforme
what causes erythema multiforme
infection (HSV, mycoplasmia pneumonia) (most common)
drugs (antibiotics, NSAIDs)
where do target lesions form
on the extremities and move towards the trunk
what are target lesions
3 layers
outer red edge
pale pink rink (raised due to oedema)
central blistering
what is stevens-johnson syndrome
blistering erosive lesions which causes the epidermis to separate from the dermis
what causes stevens-johnsons syndrome
drug reactions (majority) such as antibiotics, anticonvulsants
A 12 year old boy is admitted to hospital with multiple small (2-3cm) skin lesions across his lower legs, buttocks, elbows and knees. The rash is non-tender, symmetrical, maculopapular and dark purple in colour. His right knee is in pain, and appears swollen and hot. The mother complains about the hygiene of hospital food, as her son has also had “terrible tummy pains” and diarrhoea since getting here. His urine dipstick shows microscopic haematuria. Prior to this his health has been good, apart from a throat infection he had 2 weeks ago, from which he has recovered. Select the likely diagnosis:
Immune Thrombocytopaenic Purpura Disseminated Intravascular Coagulation Henoch-Schönlein Purpura Acute leukaemia Haemolytic-uraemic syndrome
Henoch-Schönlein Purpura
what is Henoch-Schönlein Purpura
a small vessel vasculitis
what Ig is associated with Henoch-Schönlein Purpura
IgA
what sort of hypersensitivity reaction is associated with Henoch-Schönlein Purpura
type III
what commonly precedes Henoch-Schönlein Purpura
a strep throat infection
what is the triad of Henoch-Schönlein Purpura
purpura
arthitis
abdo pain
