10. Derm Flashcards
When does eczema typically occur / resolve by?
-Usually first onset is <6months
-Clears in 50% by 5yrs, 75% by 10yrs
What can cause eczema flare ups?
-Dry skin
-Irritants
-Infection
-Sweating / heat
-Emotional stress
-Allergies
How does the distribution pattern of eczema vary with age?
INFANTS - cheeks, trunk
CHILDHOOD - flexors (sometimes extensors), wrists, ankles
ADOLESCENTS - flexors, head + neck, nipples, palms, soles
What is the main complication from eczema?
-Secondary bacterial infection
–Bacterial - staphylococcal
–Viral - herpes zoster
How should eczema be managed?
GENERAL
-Avoid irritants
-Avoid soap
-Wet wraps to avoid itching
-Sedative antihistamines if affecting sleep
MILD
1. Emollients - prevent skin drying
–For wet areas = water based creams
–For dry areas = oil based cream
2. Consider topical hydrocortisone 1% for a flare (48h)
MODERATE
1. Emollients
2. Consider topical Betamethasone valerate 0.025% (48h)
3. Consider antihistamine eg cetirizine, loratadine (1 month)
SEVERE
1. Emollients
2. Consider topical Betamethasone valerate 0.1% (48h)
3. Consider antihistamine eg cetirizine, loratadine (1 month)
4. Consider oral steroids (refer to dermatology)
INFECTED (eczema herpeticum)
1. Admit for IV acyclovir / flucloxacillin
2. Fusidic acid for topical treatment
What are the two types of impetigo and when do they usually occur?
Bullous impetigo (staph aureus)
Non-bullous impetigo (most common, mostly staph aureus but also strep pyogenes)
-Very common especially in warm weather, contagious
NB MRSA is becoming an increasingly common causative organism
Who is more likely to get impetigo?
Bacteria enters through superficial breaks in the skin so those with:
-Eczema
-Herpes
-Scabies
-Head lice
-Bites
How should impetigo be managed?
-Exclusion from school due to contagious nature until scabbed / healed over
-To remove crusts:
–Bathe in cetrimide + water
–Fusidic acid cream / mupirocin if MRSA
-For multiple lesions:
–Flucloxacillin PO / erythromycin
What can cause nappy rash?
1.AMMONIACAL DERMATITIS
-Irritant, most common cause, common with disposable nappies (chemicals)
-Erythematous / papulovesciluar lesions, fissures, erosions
-Skin folds spared
2.CANDIDAL NAPPY RASH
-Bright red rash with clear demarcated edge
-Inguinal folds usually involved, may have oral thrush
3.SEBORRHOEIC NAPPY RASH
-Pink, greasy lesions with yellow scale
-Often in skin folds, cradle cap may be present
4.PSORIATIC NAPPY RASH
-Appearas similar to seborrhoeic dermatitis
-FHx of psoriasis
How should nappy rash be managed?
- Ammoniacal dermatitis = regular washing, expose to air, sudocrem
- Candidal = topical imidazole, no barrier cream until settled
- Seborrhoeic = mild topical steroids
Barrier creams = zinc, castor oil
What is Stevens-Johnsons syndrome?
-Rare but serious disorder of the skin + mucus membranes
-Often a reaction to medication or infection
-Flu-like symptoms initially followed by a painful red / purple rash that spreads and blisters
-SEVERE form = erythema multiforme major
-EXTREME = toxic epidermal necrolysis
What causes SJS and how does it present?
CAUSES:
-Drugs especially anticonvulsants or sulphonamides
-Increased risk with HIV, SLE
PRESENTATION:
-Nikolsky’s sign = epidermal layer sloughs off when pressure applied to erythematous area
-Target lesions
-Polymorhpic erythema - blistering mucosa in conjunctivae, mouth, genitals
-Diagnosis confirmed on skin biopsy
How is SJS managed?
-Identify cause and stop (if drug-related)
-Dexamethasone
-Emollients
-Fluids + nutritional support
What is erythema nodosum and what causes it?
-Inflammation of subcutaneous fat causing tender, erythematous, nodular lesions
-Usually self-limiting but can be a sign of something serious
-Typically affects older children
CAUSES:
-Infection – TB, streptococcus, brucellosis
-Systemic disease – sarcoidosis, IBD
-Malignancy / lymphoma
-Drugs – penicillins, COCP, sulphonamides
-Pregnancy
How does erythema nodosum present?
-Multiple nodules on shins (discrete, large, hot, red, tender), occasionally on thighs + forearms
-Gradually appear over 10 days
-Resolve over 3-6 weeks - colour changes similar to fading bruises, no scarring
-Associated features:
–Uveitis
–Fever, malaise, arthralgia
–Diarrhoea, constipation, abdo pain
