Dermatology Flashcards
You are reviewing a 14-year-old boy who has just returned from a holiday abroad. His mum has noticed a widespread rash on his back. He has complained of some itching but is otherwise well. On examination, he has a large number of light brown macules and confluent patches affecting most of his back and chest. The examination is otherwise unremarkable. Diagnosis? Mx?
Pityriasis Versicolor
- Fungal skin infection
- noticeable after time in sun (skin darker → white/light brown patches)
Mx:
- ketoconazole 2% shampoo
- topical anti fungal cream if only very small area affected
You are seeing a 15-year-old boy who has developed a widespread rash over the last week. It seemed to start from a single patch on his abdomen that he first noticed 10 days ago.
On examination, he has a symmetrically distributed rash consisting of discrete pink/red lesions which are 0.5-1cm in diameter. Most are flat, but some appear slightly raised. Some have fine scales along the edges. They are not painful or itchy.
He is otherwise well and his observations are normal.
Pityriasis rosea
- links to viruses, aetiology unclear
- self-limiting, resolve within 12 weeks with no LT complications
Mx:
- none required
- if itch → emollients, topical corticosteroids or antihistamines
You are reviewing a 5-year-old girl whose mum has been concerned about a rash. This initially started on the trunk before spreading to the rest of the body. Mum thinks she has had a temperature for 1 or 2 days prior to this.
On examination, you note a generalised, rough-textured, pin-point rash. Her tongue has a white coating through which you can see some red papillae.
She has no significant past medical history and no known allergies.
Diagnosis and features?
SCARLET FEVER
- reaction to erythrogenic toxins from Group A haemolytic streptococci (Strep progenes)
- 2-6 y/o, peak 4 y/o
- spread respiratory route (inhalation/ingestion respiratory droplets or direct contact with nose and throat discharges e.g. sneezing and coughing)
Features:
- Fever = 24 - 48 hours
- malaise, headache, N+V
- sore throat
- ‘strawberry tongue’
Rash
- Fine punctuate erythema (‘pinhead’), appears torso first and spares palms and soles
- flushed appearance with pallor
- more obvious in flexures
- ‘rough sandpaper’ texture
- desquamination later on, especially around fingers and toes
Ix = THROAT SWAB but abx IMMEDIATELY
Scarlet fever mx
Notify the Health Protection Unit (HPU)
Antibiotics
- Phenoxymethylpenicillin (penicillin V)- QDS for 10 days
- Azithromycin ( if penicillin allergy)
- Treatment for 10 days is needed to prevent complications such as acute glomerulonephritis and rheumatic fever
Stay away from nursery/school for 24 hours after starting antibiotics
Paracetamol or ibuprofen can be given for symptomatic relief
Symptoms should settle down after around 1 week
Complications of scarlet fever = otitis media (MOST COMMON), rheumatic fever, acute glomerulonephritis, invasive infection (e.g. bacteraemia, meningitis, necrotising fasciitis)
Causes of napkin (‘nappy’) rashes
candida dermatitis = beefy red plaques in skin folds/flexures, satellite lesions
General management points
- disposable nappies are preferable to towel nappies
- expose napkin area to air when possible
- apply barrier cream (e.g. Zinc and castor oil)
- mild steroid cream (e.g. 1% hydrocortisone) in severe cases
- management of suspected candidal nappy rash is with a topical imidazole. Cease the use of a barrier cream until the candida has settled
Management of napkin (‘nappy’) rashes
What causes hand, foot and mouth disease
intestinal viruses of the Picornaviridae family (most commonly coxsackie A16 and enterovirus 71). It is very contagious and typically occurs in outbreaks at nursery
Clinical features of hand, foot and mouth disease
- mild systemic upset: sore throat, fever
- oral ulcers
- followed later by vesicles on the palms and soles of the feet
A 7-year-old girl is brought in to see her GP by her mother, who states that she has had a sore throat and developed a skin eruption for the last couple of days. On examination, you note 3-4 mm erythematous macules and papules on the dorsum of her hands and her heels. You diagnose her with hand, foot and mouth disease
Mx of hand, foot and mouth disease
- children do not need to be excluded from school
- the HPA recommends that children who are unwell should be kept off school until they feel better
- they also advise that you contact them if you suspect that there may be a large outbreak.
What is achondroplasia? Features, main risk factor
SHORT STATURE, AD, FGFR-3 mutation → abnormal cartilage
features:
- short limbs (rhizomelia) with shortened fingers (brachydactyly)
- macrocephaly with frontal bossing and narrow foramen magnum
- midface hypoplasia with flattened nasal bridge
- ‘trident’ hands
- lumbar lordosis
The main risk factor is advancing parental age at the time of conception.
Mx of achondroplasia
There is no specific therapy. However, some individuals benefit from limb lengthening procedures. These usually involve application of Ilizarov frames and targeted bone fractures. A clearly defined need and end point is the cornerstone of achieving success with such procedures
Rash and skin lesions in children buzzwords
HHV3 = VZV
HHV4 = EBV
HHV5 = CMV
HHV6 + HHV7 = Roseola
HHV8 = Kaposi’s sarcoma
Atopic eczema epidemiology
15-20% children, becoming more common
before 2 years, years in 50% by 5 years and in 75% by 10 years
Atopic eczema features
- itchy erythematous rash (repeated scratching may exacerbate affected areas)
- in infants, face and trunk are often affected
- younger children = extensor surfaces
- older children = flexor surfaces and creases of face and neck
Genital area often spared as nappies allow the skin to retain moisture
How do we manage atopic eczema?
Eczema herpeticum caused by…
features
Eczema herpeticum (EH) is a painful, blistering rash caused by the herpes simplex virus 1 or 2
Commonly seen in children with atopic eczema
Rapidly worsening painful eczema, clustered blisters, punched-out erosions)
Roseola infantum (exanthema subitum/sixth disease): which virus, features
HHV6, 6 months to 2 years
Features:
- high fever lasts few days followed by maculopapular rash
- Nagayama spots = papular enanthem on uvula and soft palate
- febrile convulsions 10-15%
- diarrhoea and cough
other consequences of HHV6 infection:
- aseptic meningitis
- hepatitis
school exclusion not needed
Seborrhoeic dermatitis and mx
erythematous rash with coarse yellow scales
reassure = resolve over few weeks/months (by 8 months)
scalp affected infants (cradle cap)
- massaging olive oil/vegetable oil onto scalp to loosen scales and then brush gently with soft brush and wash off with shampoo
- thicker scales = soak overnight with the oil/petroleum jelly and then shampooed in the morning
- consider topical hydrocortisone lotion once/twice daily
Children scalp
- shampoo containing = pyrithione zinc, coal tar, salicylic acid, selenium sulphide, ciclopirox
- or antifungal shampoos = ketoconazole, miconazole
- use 2-3x/day until sx disappear
Non-scalp areas
- infants = bathing 1/d using emollient as soap substitute
- topical corticosteroids/antifungals = desonide, hydrocortisone, ketoconazole
Consider dermatology referral if it lasts >4w or is widespread
