Dermatology Flashcards
What is eczema?
a chronic atopic condition caused by defects in the skin barriers, leading to inflammation of the skin
Presentation of eczema?
dry, red, itchy and sore patches of skin over the flexor surfaces
Mx of eczema?
maintenance -> emollients
flares -> thicker emollients, topical steroids, wet wraps
severe flares -> systemic steroids, antibiotics
specialists -> zinc impregnated bandages, topical tacrolimus, phototherapy, methotrexate, azathioprine
Steroid ladder of topical steroids?
hydrocortisone 0.5%, 1%, 2.5%
eumovate
betnovate
dermovate
Most common opportunistic bacterial infection in eczema?
staph aureus
What is eczema herpeticum?
viral skin condition caused by HSV or VZV
usually occurs in patient with pre-existing skin condition that allows the virus to enter the skin
Presentation of eczema herpeticum?
patient who suffers with eczema develops a painful, widespread, vesicular rash
systemic symptoms such as fever, lethargy, irritability, reduced oral intake
lymphadenopathy
Mx of eczema herpeticum?
clinical diagnosis
viral swabs to confirm
acyclovir (oral or IV)
Complications of eczema herpeticum?
life-threatening, particularly in immunocompromised children
bacterial superinfection
DDx for non-blanching rash?
meningococcal septicaemia
HSP
ITP
acute leukaemias
HUS
mechanical
traumatic
viral illness
Cause of non-blanching rash?
bleeding under the skin
petechiae and purpura
Presentation of acne vulgaris?
macules
papules
pustules
comedomes
blackheads
ice pick scars
hypertrophic scars
rolling scars
Mx of acne vulgaris?
topical benzoyl peroxide
topical antibiotics
oral antibiotics (lymecycline)
COCP in females
topical retinoids
oral retinoids
Side Effects of isotretinoin?
teratogenic
dry skin and lips
photosensitivity
suicidal ideation
SJS and TEN
Examples of viral exanthemas?
measles
Scarlet fever (not viral)
rubella
Duke’s disease
Parvovirus B19
roseola infantum
Presentation of measles?
fever, coryzal symptoms, conjunctivitis
Koplik spots on buccal mucosa
rash starts on face, behind ears 5 days after fever, and spreads to rest of body
erythema, macular rash
Mx of measles?
self-resolving
isolation
notifiable disease
monitor and treat complications
Complications of measles?
pneumonia
diarrhoea
dehydration
meningitis
encephalitis
hearing loss
vision loss
death
What causes measles?
measles virus
What causes Scarlet fever?
Group A Strep (strep pyogenes)
Presentation of Scarlet fever?
red-pink, blotchy, macular, ‘sand-paper’ rash starts on trunk and spread outwards
fever
lethargy
flushed face
Strawberry tongue
sore throat
cervical lymphadenopathy
Mx of Scarlet Fever?
phenoxymethylpenicillin (penicillin V) for 10 days
notifiable disease
off school for 24hrs after starting antibiotics
Complications of Scarlet Fever?
other associated diseases with Strep A
post-streptococcal glomerulonephritis
acute rheumatic fever
What causes rubella?
rubella virus
Presentation of rubella?
erythema macular rash starting on face and spreading to rest of the body
fever
joint pain
sore throat
cervical lymphadenopathy
Mx of rubella?
supportive, self-limiting
notifiable
avoid pregnant women
school exclusion for 5 days after appearance of rash
Complications of rubella?
thrombocytopenia
encephalitis
congenital rubella syndrome to fetus in pregnant women
Other names for parvovirus B19?
fifth disease
‘slapped-cheek’ syndrome
erythema infectiosum
Presentation of parvovirus B19?
fever
coryzal symptoms
lethargy
diffuse, bright red rash on both cheeks
reticular rash on body
Mx of parvovirus B19?
self-limiting
supportive management
no exclusion once rash has formed
Complications of parvovirus B19?
occur in immunocompromised, pregnant and haematological conditions
aplastic anaemia
encephalitis and meningitis
pregnancy complications including fetal death
hepatitis, myocarditis, nephritis
What causes roseola infantum?
human herpes virus 6 and sometimes human herpes virus 7
Presentation of roseola infantum?
high fever
rash appears after fever settles
Complications of roseola infantum?
febrile convulsions
What is psoriasis?
chronic autoimmune condition that causes recurrent symptoms of psoriatic skin lesions
patches of psoriasis are dry, flaky, scaly, faintly erythematous plaques that commonly form over the extensor surfaces of elbows and knees and on the scalp
Types of psoriasis?
plaque psoriasis
guttate psoriasis
pustular psoriasis
erythrodermic psoriasis
Key features of psoriasis?
Auspitiz sign (bleeding)
Koebner phenomenon (scars)
residual pigmentation of skin
Mx of psoriasis?
depends on severity of the lesions
psychosocial support
topical steroids
topical vit D analogues
topical dithranol
tacrolimus (adults only)
phototherapy with narrow band UVB light
systemic treatment by specialist
Psoriasis associations?
nail changes (pitting, onycholysis, thickening, discolouration, ridging)
psoriatic arthritis
depression and anxiety
incr. risk of CVD
What is erythema multiforme?
widespread, itchy, erythematous rash that forms characteristic ‘target’ signs
caused by hypersensitivity reaction
Causes of erythema multiforme?
hypersensitivity reaction
viral infections
medications
HSV
mycoplasma pneumoniae
Presentation of erythema multiforme?
widespread, itchy, erythematous rash
characteristic ‘target’ lesions
stomatitis
mild fever
muscle and joint aches
headache
flu-like symptoms
Mx of erythema multiforme?
clinical diagnosis
identify underlying cause and treat
most of the time resolves spontaneously
severe cases -> IV fluids, analgesia and steroids
What are urticaria?
aka hives
small itchy lumps that appear under the skin
may be associated with patchy erythematous rash
caused by release of histamine and mast cells
Causes of acute urticaria?
allergies
contact with chemicals
medications
viral infections
insect bites
dermographism
Types of chronic urticaria?
chronic idiopathic urticaria
chronic inducible urticaria
autoimmune urticaria
Mx of urticaria?
antihistamines
short course of oral steroids for severe flares
very severe:
anti-leukotrienes
omalizumab
cyclosporin
What is chickenpox?
highly contagious vesicular rash caused by the varicella zoster virus
Presentation of chickenpox?
widespread, erythematous, itchy vesicular blistering lesions
usually starts on trunk or face and spreads outwards
fever
itch
general fatigue and malaise
lesions scab over and then child is no longer contagious
Complications of chickenpox?
bacterial superinfection
dehydration
conjunctival lesions
pneumonia
encephalitis (ataxia)
reactivation as shingles or Ramsay-Hunt
Mx of chickenpox?
avoid pregnant women
school exclusion until lesions crust over
supportive care in children
antihistamines and calamine lotion
acyclovir in immunocompromised and >14
manage complications
What is hand, foot and mouth disease?
blistering lesions over the hand, feet and mouths caused by the Coxsackie A virus
Complications of hand, foot and mouth disease?
dehydration
bacterial superinfection
encephalitis
What is molluscum contagiosum?
small, flesh-coloured papules that characteristically have a central dimple
caused by the molluscum contagiosum virus, a type of poxvirus
Mx of molluscum contagiosum?
simple reassurance and education
avoid sharing towels
avoid scratching
refer to specialist if immunocompromised or if problematic areas:
cryotherapy
topical potassium hydroxide, benzyl peroxide, tretinoin
What is pityriasis rosea?
generalised, self-limiting rash of unknown cause
may be cause by HHV 6 or 7 but unknown
Presentation of pityriasis rosea?
characteristic herald patch - faint red or pink, scaly oval shape on the torso
spreads in a ‘Christmas tree’ distribution
generalised itch
low grade pyrexia
headache
lethargy
Mx of pityriasis rosea?
resolves within 3 months
non-contagious
reassurance
itching (emollients, topical steroids or sedating antihistamines)
What is seborrheic dermatitis?
inflammatory skin condition that affects the sebaceous glands
typically affects scalp, nasolabial folds and eyebrows
Presentation of infantile seborrheic dermatitis?
aka cradle cap
crusted flaky dry scalp
usually resolves by 4 months age, can last up till 12 months
Mx of infantile seborrheic dermatitis?
first-line baby oil
white petroleum jelly overnight
anti-fungal (clotrimazole or miconazole)
Mx of seborrheic dermatitis?
scalp - ketoconazole shampoo, topical steroids if doesn’t work
face and body - topical antifungal (clotrimazole or miconazole), topical steroids
What is ringworm?
fungal infection of the skin
aka tinea or dermatophytosis
Presentation of ringworm?
itchy rash that is erythematous, scaly and well demarcated
ring or circular shapes with the edge more defined
Mx of ringworm?
anti-fungal creams (clotrimazole, miconazole)
anti-fungal shampoo for tinea capitis (ketoconazole)
oral anti-fungal
nail polish or oral terbinafine in resistant fungal nail infections
RFs for nappy rash (contact dermatitis)?
delayed changing of nappies
irritant soaps and vigorous cleaning
poor absorbent nappies
diarrhoea
oral antibiotics predispose to candida infection
pre-term infants
Presentation of nappy rash?
sore, red, inflamed skin in the nappy area
skin creases tend to be spared
severe cases can lead to erosions and ulcerations
Candida > nappy rash features?
rash extending to skin folds
larger red macules
well demarcated scaly border
circular pattern to rash
satellite lesions
concurrent oral thrush
Mx of nappy rash?
switch to highly absorbent nappies
change frequently
use water or gentle alcohol free soaps
ensure nappy area is dry before replacing nappy
maximise time not wearing a nappy
if superimposed bacterial or fungal infection, treat
Complications of nappy rash?
candida infection
cellulitis
Jacquet’s erosive diaper dermatitis
perianal pseudo verrucous papules and nodules
