Dermatology Flashcards
What is erythema multiforme?
- hypersensitivity reaction triggered by infections, most commonly HSV
- presents as a skin eruption characterised by typical target lesion
- there may be mucocutaneous involvement
- acute and self limiting, usually without complication
- typically affects young adults 20-40
- there is a genetic tendancy
Spot diagnosis
Erythema multiforme
- few to hundreds of skin lesions erupt in 24 hours, usually seen first on back of hands/feet and spread to limbs and trunk
- upper limb more commonly affected than lower limb
- face, neck and trunk are common sites
- may have associated mild itch or burning sensation
- initial lesions are sharply demarcated, round macules which become raised papules and form plaques
- lesions start to blister or crust and usually evolve over 72 hours
- typical lesion = tagrt lesions with 3 concentric colour zones, dusky centre, pale pink, bright red outer ring
- lips are often swollen
- may see mucous erosions/ulcers generally on lips and cheeks and tongue
What are the 2 most common causes of erythema multiforme?
- HSV 1, less commonly HSV 2
- Mycoplasma pneumonia
Treatment of severe erythema multiforme
- need to treat cause r.e. antivirals or antibiotics for mycoplasma pneumonia
- could use steroids if severe 0.5-1mg/kg/day prednisolone
- if recurrent can treat with continuous aciclovir for 6 months at dose of 10mg/kg/day in divided doses
- other treatments: dapsone, antimalarial drugs, azathoprine
Outcome for erythema multiforme
- usually resolves spontaneously without scarring over 2-3 weeks
- can take up to 6 weeks in major cases
- significant eye involvement in erythema multiforme major can rarely result in vision loss
What is pityriasis alba?
- low grade type of ezcema/dermatitis
- generally seen in children, 3-16 years old
- pityriasis refers to the characteristic fine scale and alba to its pale colour (hypopigmentation)
Clinical presentation:
> most lesions occur on face, especially cheeks and chin
> patches vary in size from 0.5 -5cm
> usually oval, round or irregular
> hypopigment is more noticable in summer and scaling is more noticable in winter
Evolution of pityriasis alba rash
- slightly scaly pink patch or plaque with palpable papular surface
- hypopigmentation with fine surface scale
- post inflammatory hypopigmentation without scale
- resolution
Spot diagnosis
Pityriasis alba (fine scale with hypopigmentation)
Treatment of pityriasis alba
- none if asymptomatic!
- otherwise can use moisturiser, mild topical steroid (0.5-1% hydrocortisone) to reduce itch if present
What is an exanthem?
- widespread rash accompanied with systemic symptoms of fever, malaise and headache
- usually infective cause such as virus or reaction to a toxin or immune response
Causes of exanthems
Varicella (chickenpox)
Measles (morbillivirus)
Rubella (rubella virus)
Roseola (herpes viraus 6B)
Erythema infectiosum (parvovirus B19)
Also include: acute HIV, IM and aminopenicillin rash, pityriasis rosea (herpes 6/7), erythema multiforme, non-specific viral exantham
Bacterial causes
- staph: toxic shock syndrome, scalded skin syndrome
- strep: scarlet fever, step toxic shock-like syndrome
Spot diagnosis
Varicella (chickenpox)
Spot diagnosis
Measles - caused by morbilivirus
What is the diagnostic oral finding in measles?
Koplik spots
- usually manifest 2-3 days prior to measles rash
- clustered white lesions on buccal mucos (opposite the lower 1st and second molars)
“grains of salt on reddish background”
How is chickenpox transmitted?
Respiratory droplet or through direct contact with fluid from open sores
Describe the characteristic rash of chickenpox.
- itchy red papules which progress to vesciles
- usually on stomach, back and face then progress to other body parts
- can see the same lesions in the mouth
- may be associated with fevers, headache, cold-like symptoms, vomiting an diarrhoea
- blisteres clear up within 1-2 week weeks but can scar
Chickenpox incubation period
- 10-21 days
Diagnosis of chickenpox
- PCR on wound swab from vesicle
- serology IgM and IgG is most useful in pregant women
Complication of varicella/chicken pox
- secondary bacterial infection of lesions
- dehydration from vomiting and diarrhoea
- exacerbation of asthma
- viral pneumonia
- shingles
More severe complications are generally seen in adults or immunocompromised children
- disseminated varicella (high morbidity)
- CNS complications: Reye syndrome, GBS, encephalitis
- thrombocytopenia and purpura
Varicella in pregnancy
- in non-immune pregnant women exposure to varicella can cause viral pneumonia, premature labour and delivery and rarely maternal death
- 25% of fetuses of mothers with chickenpox become infected
- offspinge may remain asymptomatic of develop herpes zoster at a young age without previout history of primary varicella
- however they may develop congenital varicella syndrome (TORCH)
> spontaneous abortion, fetal chorioretinitis, cataracts, limb atrophy, cerebral atrophy, microcephaly, neurological disability
When is aciclovir or varicella-zoster IG indicated?
Aciclovir
- consider in patients > 12
- immunocompromised patients
Varicella-zoster IG
- can be given in case of inadvertent exposure to virus in patients with no previous hx of chickenpox in pregnancy, or if immunocompromised
> must be given within first 96 hrs
When is a patient with chickenpox contagious?
1-2 days before the rash develops and until all the blisters have formed scabs (this can take 5-10 days)
It takes 10-21 to develop symptoms after exposure to virus
Varicella vaccination
@ 18 months
Describe the measles transmission
- highly contagious
- spread by respiratory droplets
- infectious for 2 days prior to developing symptoms and for 5 days after onset of rash
- acute infection provides almost always life long immunity
Describe the 4 clinical stages of measles.
- Incubation period
- ranged from 7-14 days, on average ~10 day
- usually asymptomatic - Prodrome
- generally 10-12 days after exposure
- fever, malaise, anorexia, conjunctivitis, cough, coryza
- 2-3 days into prodrome koplik spots appear, usually ccur 24-48 hours prior to exanthem - Exanthem
- flat red spots, 0.1-1cm diagmeter appear on 4th/5th day of symptoms
- non-itchy rash stated on face and behind ears, spreads over entire trunk and extremities with sparing of soles and palms within 24-36 hrs
- spots may joint together and often rash conicides with fever
- rash fades within 3-4 days - Recovery
- cough may persist for up to 3 weeks
Diagnosis of measles
- clinical diagnosis but now often need to do lab investigations as not commonly seen
- viral NPS swab for PCR
- blood: IgM and IgG
- investigation should be done within 5 days of rash onset
When are antibiotics indicated in measles?
- secondary bacterial infections: otitis medial, infectious diarrhoea, pneumonia, sepsis
Define the complications of measles?
Approximately 30% of cases will have one or more complications
- GIT: diarrhoea, mouth ulcers, appendictis, hepatitis, mesenteric adenitis, pancreatitis
- Ears: otitis media
- Resp: croup, pneumonia
- Cardio: myopericarditis
- Haem: thrombocytopenia, DIC
- Eyes: conjunctivitis, corneal ulceration
- Renal: glomerulonephritis, renal failure
- CNS: febrile seizures, encephalitis
- Pregnancy: premature labour, fetal loss, maternal death
What is the most severe complication of measles?
Subacute sclerosis panencephalitis
- a fatal condition, develops decades after a measles infections due to persistent of measle virus in CNS
Vaccination schedule for measles
MMR @ 12 months and 18 months
Can varicella vaccination be given to prevent primary infection?
Yes, if given within 3 -5 days of exposure primary immunisation may prevent development of disease
Can MMR be given in pregnancy?
NO!
If not previously immunised against measles should avoid pregnancy for 1 month after MMR vaccination
When is immunoglobulin indicated for measles?
- pregnant womenn
- immunocompromised patients
- infants
Ig will not prevent meales bit can reduce severity
What is rubella?
- viral disease characterised by rash, swollen glands, fever
- usually mild and not significant unless pregnant du eto risk fo congenital rubella syndrome
- also known as German measles
- causes by rubella virus
- spread through direct contact with nasal or throat secretions
- contagious for 7 days prior to rash and until 7 days after rash has appeared, generally most infectious while rash is erupting
- acute infection confers lifelong immunity generally
Signs and symptoms of rubella
- in up to 50% of cases symptoms are mild or asymptomatic
- typical incubation period 12-23 days
- common symptoms: fever, sore throatm runny nose, malaise, tender swollen glands
- Forchheimer sign: point point petechiae noted on soft palate and uvula in prodromal period
- rash begins on face and spreads to truck and extremities
- lasts for up to 5 days, may be itchy or not
- usually not as widespread as measles
- may be associated with arthralgia and arthritis
Congenital rubella
- infection in first trimester of pregnancy comes with a 50% chance of infant being affected (including miscarriafe, stillbirth, congenital rubella)
Features of congenital rubella:
> sensorineural hearing loss
> eye abnormalities: cataract, glaucoma
> congenital heart disease: PDA
> mental impairments
> meningoencephalitis
> hepatitis and jaundice
> diabetes mellitis
> thyroid malfunction
How long after MMR should females wait until trying to concieve?
3 months
What is roseola?
- caused by human herpes virus type 6B (HHV-6B) and maybe type 7
- characterised by high fever lasting for 3-5 days with runny nose, irritability and tiredness
- as fever settles, exanthem may appear on face and body
- also known as roseola infantum and exanthem subitum
What age group is roseola seen in ?
- Generally between 6 months and 3 years of age
- Most children will have had roseola by 1 (86%)
- Spread via saliva of asymptomatic family members, with a 9-10 day incubation period after exposire
Signs and symptoms of roseola.
- high fever, often up to 40deg for 3-5 days
- URTI symptoms: sore throat, cough, runny nose, congestion
- irritability and tiredness
- rash appears around day 3-5 as fever settles
- typically small rose-pink or raised red spots (2-5mm) that blanch
- some spots may be surrounded by lighter halo of pale skin
- mainly affects trunk and rarely spreads to involve face/neck/arms and legs
- non-itchy, painless and don’t blister
- can persist for up to 2 days
What is the most complication of roseola?
Febrile seizures seen in 5-15% of children
Other: encephalitis, hepatitis, myocarditis but only very rarely
12 month old child presents with rash predominantly on trunk, 3 days of high fever with URTI symptoms preceeding. Diagnosis?
Roseola infantum
What causes erythema infectiosum?
Parvovirus B19
What are the other names for slapped check?
Erythema infectiosum = slapped cheek
Also known as fifth disease
How is parvovirus B19 spread?
- respiratory droplet with incubation period of 7-10 days
Spot diagnosis
Erythema infectiosum
Fifth disease
Slapped cheek
Symptoms and complications of fifth disease
Erythema infectiosum
- symptoms: mild fever, headache, rash appears few days latera with firm red cheeks which feel burning hot, this lasts for 2-4 days which is followed yb a pink rash on limbs and truck which appears lace like
Complications:
- polyarthropathy in adults
- asplastic crisis or dangerously low blood counts in pts with autoimmune/haemolytic conditions
- spontaneous abortion, IUFD, hydros fetalis
Slapped cheek + lacy rash = ?
Erythema infectiosum
Fifth disease
Slapped cheek
Parvo B19
Young male, eruption for 2 months. Associated 5kg weight loss, several episodes of diarrhoea and abdominal discomfort.
Most likely diagnosis = dermatitis herpetiformis
DDx: pmphlolyx eczema, infections (scavies, viral, bullous impetigo), erythema multiforme, bullous pemphigoid, SLE
What is dermatitis herpetiformis?
- results from immunological response to gut mucosa to stimulation by dietary gluten
- majority of patients with dermatitis herpetiformis have coeliac disease
- gluten causes development of IgA antibodies against gluten tissue transglutaminase which cross reactions to epidermal transglutaminase
- there is an associated link with HLA-DQ2 and 8
- patient may describe personal or family history of other autoimmune disorders (hashimoto, pernicious anaemia, T1DM)
How is dermatitis herpetiformis diagnosed and treated?
Diagnosis
- biopsy: take 1 sample from lesion and 1 sample for perilesional skin
- blood: anti-transglutaminase and anti-endomysial antibodies
Management
- gluten free diet
- dapsone is initial treatment of choice but need to monitor for s/e (haemolytic anaemia and methhaemoglobinaemia, must have FBC, G6PD and renal + liver function must be done prior)
- potent topical steroids can also be used
Description of the dermatitis herpetiformis
- pruritic, polymorphic, grouped and symmetrical lesions consisting of erythema, urticarial plaques, palpules, vesicles , blisters
- followed by erosions, abrasions and hyperpigmentation
- seen on extensor surfaces of knees/elbows, shoulders, buttocks, sacral region and scalp
Describe rash of pompholyx eczema
- abrupt onset of small, clear vesicles or bullae on palmes and or soles
- prodromal itching or burning sensation
- vesicles and bullae drug out and resolve without rupturing, desquamation 2-3 weeks after
First line treatment for pityriasis versicolour
- econazole 1% left overnight for 3 nights
- ketoconazole 2% shampoor daily for 5 days
- miconazole 2% shampoo daily for 10 days
- selenium sulfide 2.5% shampoon to skin for 7-10days
If unresponsive = PO fluconazole 400mg STAT
Features which increase risk of BCC recurrence
Management of warts
Most cutaneous warts are self limiting and resolve within 2 years. Salicylic acid has level I-A evidence of advantage over placebo. Cryotherapy with liquid nitrogen has level I-B evidence. It has not been shown to be superior over other treatments or placebo. It may however have better efficacy for plantar warts.
Surgical excision is not recommended first line due to scarring, pain and a high rate of recurrence.
Define timing of ROS by location
Face: 3–5 days
Scalp: 7–10 days
Arms: 7–10 days
Torso: 10–14 days
Legs: 10–14 days
Dorsum of hands or feet: 10–14 days
Palms or soles: 14–21 days
Typical causes of localised itchy rashes.
a) scalp
b) back
c) hands
d) genitals
e) legs
f) feet
A) Scalp: seborrhoeic dermatitis, head lice
B) Back: Grover disease
C) Hands: Pompholyx, irritant, contact dermatitis
D) Genital: candida, lichen sclerosis
E) Legs: venous eczema
F) Feet: tinea pedia
What are the hallmark features of scarlett fever?
Fever, malaise, sore throat, headache
Whole body rash which spares the face, feels like sandpaper
Strawberry tongue
Spot diagnosis
Strawberry tongue seen in scarlett fever
Spot diagnosis
Bullous pemphigoid
What is Grover’s disease?
Transient acantholytic dermatosis
- itchy truncal rash characterised
- often affects males > 50
- often starts suddenly and is more common in winter than summer
- characteristics: central back/mid chest, small red, crusted or eroded papules, intensely itchy
- can be treated with moisturiser, topical steroid a course of tetracycline or oral antifungal
60 year old male, itchy rash on trunk, appeared suddenly this winter. Spot diagnosis…
Transient acantholytic dermatosis
Grover’s disease
Spot diagnoisis for diffuse, greasy scaling in infant.
Seborrhoeic dermatitis
Also known as “cradle cap”
- salmon pink patches which may flake or peel
- not especially itchy so bubs usually appear undisturbed even when the rash is generalised
What causes seborrhoeic dermatitis?
- pathogenesis not completely understood
- associated with proliferation of skin commensals i.e. malasezia in its yeast form (non-pathogenic)
- its metabolites cause an inflammatory reaction
- seen in infants: babies < 3 months and usually resolves within 6-12 months
Spot diagnosis
Seborrheoic dermatitis
What are the typical features of adult seborrhoeic dermatitis?
- winter flares, improves in summer following sun exposure
- minimal itch
- combinatio nof oily and dry mid-facial skin
- ill-defined scaly patches on scalp
- blepharitis: scaly red eyelid margins
- salmon pink, thin, scaly and ill defined plaqus in skin folds on both sides of face
- petal or reing shaped flaky patches on hair line and anterior chest
- rash in armpits, under breast, in groin and genital creases
-
Spot diagnosis
Seborrhoeic dermatitis
- bilateral rash in skin folds
- ring or petal shapes flaky patches on hair line
What is the treatment for seborrhoeic dermatitis?
- keratolytics to remove scale: salicylic acid, lactic acid
- topical antifungals to reduce malassezia
- mild topical corticosteroids for 1-3 weeks to reduce inflammation of acut flare
- may require topical tacrolimus onitment if steroids are often required to reduce adverse effects
What is alopecia areata?
- one or more round bald patches suddenly appear
- also known as autoimmune alopecia
- 50% of cases start in childhood
- associated with thyroid disease, vitiligo and atopic eczema
- onset or recurrence often triggered by viral infection, trauma hormonal changes, stress
- characteristics: exclamation marks hairs
- spontaneous regrowth is common
Spot diagnosis
Pityriasis versicolor
- common yeast infection of the skin
- flaky discoloured patches appear on chest and back
- frequently affects young adults and more common in men
- more common in hot and humid climates
What are the clinical features of pityriasis versicolour?
- affects trunk, neck and/or arms
- patches ma be coppery brown, pale or pink
- pale patches are more common on darker skin (pityriasis versicolour alba)
- asymptomatic but sometimes mildly itchy
- caused by malassezia
Treatment of pityriasis veriscolour
- topical azol cream/shampoo (econazole, ketoconazole)
- selenium sulfide
- terbinafine gel
- ciclopirox cream/solution
- propylene glycose solution
- sodium thiosulphate solution
Apply nocte before bed for at least 3 days but up to 2 weeks
Can use oral antifungals if topical agents have failed
> suggest exercise after taking medication
16 year old male - suddent onset itchy rash, located on trunk and extremities. Well demarcated, drop like salmon papules with plaques and fine scale. History of tonsillitis (GAS).
Guttate psoriasis
- rare form of psoriasis
- tends to be seen in < 30 age group
- “gutta” is tear drop in latin
- preceeded by GAS infection usually 2-3 weeks before eruption
- often resolves within weeks to months without treatment
When should you consider referral for oral isotretinoin for acne?
- severe: cystics, nodular, very inflammatory
- is scarring
- marked negative emotional and social effect
What is first line recommendation for mild acne?
Topical retinoid (teratogenic)
- adapalene 0.1% for 6 weeks and review
- tretinoin 0.025% for 6 weeks
What is the initial treatment recommended for moderate to severe acne?
- Oral antibiotic or OCP +/- spironolactone
- doxycycline 50-100mg daily for 6 weeks
- OCP: ethinylestradiol + cyproterone
Common side effects of oral isotretinoin
- dry lips, dry eyes, dry mucosal lining of nose
- early acne flares
- chelitis
- sun sensitivity
- dru skin and dermatitis
- facial erythema
- nosebleeds
- lethargy, myalgia and joint stiffness
Causes and treatment for balanopothitis in adults
- if circumscised: psoriasis, lichen planus, lichen sclerosis, plasma cell balantitis, fixed drugs eruption, cutaneus malignancies
- if uncircumscised: usually due to candida and rarely due to strep pyogenes
Lichen sclerosis
- common cause of chronic genital skin disease
- females: external genitalia but spares vagina and associated with autoimmune disease
- males: confined to glans penis
Presents with well defined white, fine wrinkled plaque which is itchy and usually hyperkeratotic and ulcerated to due scratching
- need to refer to specialist to diagnose and treat
- often use very potent topical steroids
Candidal vulvovaginitis
- candida albicans main cause
- recurrent = more than 4 acute episodes/year
- swab to confirm species of candida
- treatment: intravaginal therapy with imidazole or nystatin
If chronic
- uncommon, ongoing itchy, dysparunia, discharge, soreness, burning, swelling, erythema and fissuring
- doesn’t mean patient is immunocompromised
- repeat swab to and treat with oral azaoles (if not pregnant)
- review treatment after 3 months
Management of pruritis ani.
- need to break the itch-scratch cycle
- cleaning perianal area gently using cotton wool
- use soap substitute
- apply barrier/oral subsitute
- consider bulk forming laxaity
- loose fitting cotton underwear
- may need to consider topical methypred topical if ongoing
- if ongoing may need specialist referral
Name 7 common blistering consitions
- bullous impetigo
- insect bites
- contact dermatitis
- burns
- pompholyx
- HSV
- varicella zoster
How would you diagnose an autoimmune blistering skin condition?
- histology + immunofluorescence
- provide fixed sample for histology and a fresh sample
Examples: bullous pemphigoid, dermatitis herpetiformis, pemphigoid gestonitis, pemphigus)
Spot diagnosis
Bullous pemphigoid
Cause of bullous pemphigoid
- antibodies against basement memebranes
- affects older people and presents as firm blisters with erythematous base
- can be localised or widespread
- refer to specialist
- apply betamethasone dipropionate 0.05% topically while waiting for specialist review
- can also use wet dressings
What rash is associated with coeliac disease?
Dermatitis herpetiformis
Spot diagnosis…
Pemphigus vulgaris - rare autoimmune disease characterised by painful blisters and ersoions.
Stevens-Johnson Syndrome (SJS)
- significant initial influenza like symptoms, widespread mucocutaneous exfoliation with or without blisteres
- onsent within weeks (up 2 months with antiepileptics)
- causes: antiepileptics, sulfonamides, allopurinol, NSAIDs, beta lactams
DRESS: drug rash with eosinophillia and systemic symptoms
- initial influenza like symptoms with exanthematic rash
- nonfollicular pusules, facial oedema, lymphadneopathy, peripheral eosinophilia (>1.5) and internal organ involvement
- can occur within 1-8 weeks but occassionally up to 4 months
- causes: antiepileptics, barbiturates, lamotrigine, sulfonamides, dapsone, minocycline, azathoprine, allopurinol, strontium
TEN: toxic epidermal necrolysis
- significant initila influenza symptoms
- widespread mucocutaneous exfolation with or without blisteres
- within weeks
- cause: antiepileptics, sulfonamides, allopurinol, NSAIDs, beta lactams
Treatment for chronic cutaneous (discoid) lupus erythematosis
- betamethasone bipropionate 0.05% topically for 4-6 weeks
OR
- mometasone furoate 0.1% for 4-6 weeks
Morphoea
- localised scleroderma
- excessive collagen deposition
- confined to skin without systemic involvement
- presents as one or more indurated plaques, start as faint purple and fase to ivory while as plaques become smooth and shiny
- plaques are devoid of hair
- refer for expert management using potent steroids
Leukocytoclastic vasculitis
- LCV, small vessel vasculitis
- generally idiopathic
- diagnosis: biopsy, FBC, CRP, ESR, urine microscopy, e/LFT
- if uncomplicated is self limiting, sx lasting for ~3 weeks
- if complicated or widespread start oral steroids and refer
Chilblains
- localised inflammatory lesions caused by cold
- develop as acutely burning, red or purple swellings in toes and fingers
- generlaly heal and resolve in 1-3 weeks
- prevent by avoiding cold and stopping smoking
- can treat with strong topical steroid and amlodipine to prevent vasospasm
- GTN has ben used to prevent but evidence is lacking
Erythrasma
- overgrown of normal commensal bacterium Corynebacterium minutissimum
- flexural rash in groin axillae and toe webs
- may resemble intertrigo or fungal infections
Rx: fusidate sodium or clarithromycin
Spot diagnosis and management
Tinea (ringworm)
Terbinafine 1% BD for 7-14 days
Topical steroid preparations and strengths
Spot diagnosis
Atopic dermatitis
- most common inflammatory skin condition world wide
- generalise skin dryness and itch
Spot diagnosis
Senorrhoeic dermatitis
Sport diagnosis
Discoid dermatitis
Spot diagnosis
Asteatotic dermatitis
Spot diagnosis
Asteatotic dermatitis
55F - cleaner. Spot diagnosis?
Contact dermatitis most likely
Drugs for treating psoriasis in primary care
Tar
Corticosteroids
Calcipotriol
Or combination therapies
Spot diagnosis
Chroinc plaque psoriasis
Spot diagnosis
Nail psoriasis
Pitting, onycholysis, yellowing and ridging
Associated with inflammatory psoriatic arthritis
Treatment for erythema nodosum
- rest
- NSAIDs
- elevate legs
- if severe symptoms: prednisolone 25mg daily for 2 weeks and taper
Granuloma annulare
- unknown cause
- presents with annular plaque (colours ranging from skin colour to red and violet)
- often margins feel beaded
- can occur anywhere on the body
- often confused with tinea
- may persist for years but can clear spontaneously
- if interferes with function can treat with betamethasone diprosone 0.05% for 4-6 weeks
Spot diagnosis
Granuloma annulare
- common inflammatory skin condition with annular, smooth, discoloured palpules and plaques
- histology shows necrobiotic granulomas
Lichen planus
- uncommon indiopathic inflammatory condition
- can be triggered by drugs or hepatitis C
- affects skin, hair, oral and genital mucosae
- characteristic; skin eruption is itchy, violet, polygonal , flat topped papules and lacy white lines
- skin lesions take 6-9 months to resolve with post inflammatory hyperpigmentation over 3-6 months
Spot diagnosis
Oral lichen planus
Spot diagnosis
Lichen planus of the nail
Necrobiosis lipoidica
- rare granulomatous skin disorder
- lesions occur on the legs
- seen in diabetics
- initially start as red nonulcerating plaques and the centres become brown/yellow with obvious telenagiectasia
Spot diagnosis
- necrobiosis lipoidica
- seen on the shins if diabetics
Pityriasis rosea
- self limiting inflammatory skin condition affecting older children and young adults
- thought to be due to a viral infection (HHV 6 or 7)
- eruption starts with a herald patch which is often mistaken for tinea
- eruption occurs around 2 weeks later with scaly, oval salmon coloured macules
- confined to trunk and proximal limbs and are arranged along the skin creases
- usually resolved spontaneously within 6-8 weeks
- if severe itch can treat with betamethasone
What rash is thought to be due to reactivation of human herpes virus 6 or 7?
Pityriasis rosea
Spot diagnosis for this herald patch?
Pityriasis rosea
- may occur a few days after viral URTI
Polymorphic light eruption
- idiopathic photosensitivity disorder
- most common in cooler climates
- within sun exposure pruritic erythematous papules, plaques or vesicular lesions appear on exposed skin (forearms or chest)
- lesions fade without scarring over several days
- ddx: solar urticaria, SLE, photosensitive drug eruption
Pyoderma gangrenosum
- associated with inflammatory bowel disease, inflammatory arthritis, haematological proliferative disorders
- destructive, non-infective, inflammatory ulcer which is often painful
- starts as inflammatory papule/pustule which slowly breaks down to form enlarging ulcer
- raised purplisk edges
- perform biopsy and culture to r/o other atypical infection and vasculitis
- treatment = immunosuppression, prednisolon 25mg daily for 2 weeks and taper while awaiting specialist referral
Spot diagnosis in patient with ulcerative colitis?
Pyoderma gangrenosum
Sweet syndrome
- acute febrile neutrophilic dermatosis
- painful erythematous to blue plaque appear rapidly on face/neck and limbs
- usually accompnaied by fever and neutrophil leucocytosis
- generally after URTI but can be associated with GIT infections, IBD, pregnancy, drugs, rheumatoid arthritis, sarcoidosis, malignancy
- usually responds well to systemic corticosteroids
Patient who is febrile and unwell presents with this rash shortly after URTI. Spot diagnosis.
Sweet syndrome
Acute febrile neutrophillia dermatosis
Other name for solar keratosis
Actinic keratosis
Solar keratosis/actinic keratosis
- considered pre-cancerous form of SCC
- often flat or thickened papule/plaque, whit or yellow with horny surface
- > 10 solar keratosis leads to a risk of 10-15% of developing SCC
Dermoscopic view of actinic keratosis (non pigment on facial skin)
- “strawberry pattern”
- border well dermarcated but may merge in surrounding skin
- pink to red pseudonetwork created but straight or wavy vessels surrouding hair follicles
- skin coloured or white circles around a yellowish clod
- surface scale
Dermoscopic actinic keratosis on nonfacial skin
- irregular shape
- surface scale
- erythema and sometimes with dotted vessles
- rosettes
- short shiny streaks
Seborrhoeic keratosis
- well defined, benign warty lesions that are often pigmented
- start to appear around 30-40 but numbers increase with age
- clinically flat lesions are difficult to distinguish form lentigo maligna
- often itchy and do not need treatment!
Spot diagnosis. Cancerous or benign?
BENIGN
Seborrhoeic keratosis
Spot diagnosis
Seborrhoeic keratosis
Lentigo simplex
- brown to black macule M 5mm diameter
- can occurs anywhere but less common on mucosa
- do not need treatment!
- can be difficult to distinguish from melanoma
Melanocytic naevi
- also known as moles
- benign localised proliferation so of melanocytes
- generally develop in children
- begin as macules, but can become raised commonly with gradual loss of pigmnet
- having many naevi is a risk factor for melanoma
- however most melanomas arise “de novo” so prophylactic removal of benign naevi is not recommended
Classification of melanocytic naevi
Junctional naevus: groups or nests at the junction of epidermis and dermis –> flat mole
Dermal naevus: naevis cell nests in dermus, papule/plaque or nodule
Compound naevus: nests at epidermal-dermal jdunction, central raised area surrounded by flat patch
Combined naevus: two distinct types of mole withion same lesion, usually compound + blue naevus
Dermatoscopic patterns of melanocytic naevi
- reticular: lattic of intersecting brown lines
- globular: aggregated brown oval structures
- blue: steel blue uniform, structureless
- starburst: radial lines around periphery
- acral: on palms and soles, made up of parallel lines
Dysplastic naevi
- lesions are benign and typically larger, flat and raised compondent, irregular “smudgy” borders, vary in colour
- generally occur on trunk
- can become malignant but generally don’t
- if excising for concerns take with a 2mm border
Nodular BCC
- most common type of BCC
- shiny or pearly nodules with a smooth surface
- may have central depression or ulceration, edges appear rolled
- blood vessels cross surface
Spot diagnosis
Nodular BCC
- raised, pearly with rolled edge and central ulceration
Superficial BCC
- most common in younger adults
- slightly scaly appearance with irregular plaque
- thin transluenct rolled border
- multiple micro-erosions
Spot diagnosis
Superficial BCC
- slight rolled border
- multiple micro-erosions, slight scale with irregular border
Morphoeic BCC
- usually found in mid-facial sites
- waxy, scar like plaque with indistinct borders
- wide and deep subclinical extension
- may infiltrate cutaneous nerves (perineural spread)
- also knowns of sclerosing BCC
What type of BCC is this?
Morphoeic
- scar like
- waxy appearance
- indistinct borders
Basosquamous carcinoma
Mixed BCC and SCC
Spot diagnosis
Squamous cell carcinoma
Spot diagnosis
Keratocanthoma
What is your spot diagnosis and management?
Superficial spreading melanoma
- excisional biopsy with 2mm margins
- A: asymmetrical
- B: irregular
- C: irregular
- D: > 6mm
- E: unsure
Spot diagnosis
Acral melanoma
