Dermatology Flashcards
What % of children are affected by atopic eczema?
20%
Lifetime risk subsequent malignant melanoma from congenital pigmented naevi >9cm
4-6%
Itchy rashes
Eczema Chickenpox Urticaria/allergy Contact dermatitis Insect bites Scabies Pityriasis rosea
Characteristic distribution of nappy rash
Buttocks, perineal region, lower abdo, upper thighs
Sparing flexures
Mx nappy rash
- Advise highly absorbent, disposable nappies,
- Regularly changing, careful drying
- Nappy off for as much as possible
- Avoid soaps, lotions, etc.
- Barrier protection e.g. sudocreme
- If inflamed - hydrocortisone 1% for 7 days
- If candida (satellite lesions) - clotrimazole
- If bacterial - fluclox
Presentation of seborrhoeic dermatitis
Cradle cap - thick, yellow, adherent layer
Then break out in erythematous rash similar to nappy rash distribution + flexures
NOT ITCHY (unlike eczema)
What do children with seborrhoeic dermatitis have an increase risk of developing?
Atopic eczema
Mx seborrhoeic dermatitis
Emollients
Sulphur/salycylic acid ointment
Topic steroids
Differences between atopic eczema and serborrhoeic dermatitis
AE - ITCHY, generally not common before 2 mos
SD - not itchy, common before 2 mos. Yellow, scaly cap
When does atopic eczema usually present?
First year of life
What % atopic eczema resolved by 16 years
75%
Proportion of children with atopic eczema going on to develop asthma
1/3
Presentation atopic eczema
Itchy rash -
Face and trunk in inftants
Flexures in children
Causes of exacerbations of eczema
Bacterial infection (e.g. staph) Viral infection (e.g. HSV) Allergens Heat/humidity Stress
Mx of eczema
- Avoidance of triggers
- Cut nails short, loose cotton clothing
- Emollients (E45, cetraben, dermol500, diprobase) - use liberally and frequently
- Mild steroids e.g. hydrocortisone
- Moderate steroids e.g.
Mx of eczema
- Avoidance of triggers
- Cut nails short, loose cotton clothing
- Psychosocial support
- Emollients (E45, cetraben, dermol500, diprobase) - use liberally and frequently
- Mild steroids e.g. hydrocortisone
- Moderate steroids e.g. eumovate
- Calcineurin inhibitors
- Occlusive bandages (lichenification) w/ zinc and tar
- Potent steroids e.g. betnovate
- Very potent steroids e.g. dermovate
- PO steroids
- Anti-histamines e.g. cetirizine
Eczema steroid ladder
Hydrocortisone
Eumovate
Betnovate
Dermovate
Indications for referral eczema
Suspected eczema herpeticum
Severe atopic eczema not responded within 1 week
Failure of bacterial infected treatment
Severe recurrent infections
Eczema treatment w/ lichenifcation
Occlusive bandages with zinc and tar
Cause of viral warts
HPV
Mx viral warts
Daily application salicylic acid paint
Cryotherapy
Which virus causes molluscum contagiosum
Pox
Mx molluscum contagiosum
Watch and wait (resolves spontaneously after 6-12 months)
Cryotherapy for chronic lesions
Molluscum contagiosum time course
6-12 months
Skin coloured pearly papules with central umbilication
Molluscum contagiosum
Annular lesions with crusted egde. Circular
Ringworm
Which fungi cause ringworm
Dematophytes invade dead keratinous structures
Mx ringworm
Topical antifungals e.g. terbinafine cream/clotrimazole
Systemic antifungals for severe infection (e.g. terbinafine, itraconazole)
Diagnosis ringworm
Fungal hyphae on skin scrapings
Common cause (source of fungi) ringworm
Pets
Burrows, vesicles, papules on palms, soles, between fingers and toes.
Severe itching
Scabies
Mx scabies
5% permethrin for WHOLE FAMILY
Washed off after 8-12 hours then reapplied 2 weeks later
Chlorphenamine (drowsy anti-H) for sleep/itchy.
Complications of scabies
Secondary bacterial infection
Slowly resolving nodular lesions
Commonest lice infestation in children
Headlice (pediculosis)
Itchy scalp/nape
Suboccipital lymphadenopathy
Headlice (pediculosis)
Mx of headlice
Wet combing with fine tooth comb
Dimeticone 4% lotion left in overnight and repeated 1 week later
Mx periorbital cellulitis
High dose IV abx
- Ceftriaxone
Incision, drainage and culture of peri-ocular abscess
Mx tinea capitis
Systemic antifungal therapy - PO terbinafine
Advice for ringworm infection
Loose fitting clothing
Wash affected areas daily and dry thoroughly
Avoid scratching
Do not share towels
Wash clothes and bed linen frequently
Commonest psoriasis in childhood
Guttate
Presentation of guttate psoriasis
Raindrop erythematous scaly patches of trunk and upper limbs
Typically follows streptococcal/viral throat or ear infection
Mx guttate psoriasis
Phototherapy (narrow band UVB)
Emollients
Potent steroids
Vitamin D analogues on plaques
Single round scaly macule (Herald’s patch)
Pityriasis rosea
Origin of pityriasis rosea
Viral
Mx of pityriasis rosea
None - self resolving in 4-6 weeks
Pathophysiology of acne
Around puberty, increased production of sebum, androgenic stimulation of sebaceous glands.
Obstruction of sebaceous follicles = acne
Features of acne
Open comedones - blackheads
Closed comedones - whiteheads
Nodules, pustules, cysts
Advice for acne
Gentle cleansing 2x/day - do not overclean
Avoid squeezing
Healthy diet
Non-comedogenic make up/emollients
(Treatments are effective but may take up to 8 weeks to have desire effect)
Mx of acne
Conservative advice
- Topical retinoids or antibiotics (clindamycin)
- Benzoyl peroxide
- PO abx (lymecyclin/doxycycline) - change to different abx after 3 months if no improvement
- Roaccutance (dermatology r/f)
- COCP (NOT progesterone only)
Which contraception should be avoided in girls with acne
Prosterone only - with androgenic activity can worsen acne
What must be checked for patients on roaccutane
Must be on contraception (teratogenic)
Regular LFT checks
Mx hand foot and mouth disease
Symptomatic support (hydration, analgesia) Does not need school exclusion
Pathophysiology of milia
Keratin trapped under surface of skin
Mx milia
Most cases clear by themselves
Cosmesis - fine needle, cryotherapy, laser, dermabrasion, chemical peeling
Causes erythema nodosum
IBD
TB
Drug reaction
Idiopathic
Causes erythema multiforme
HSV
Mycoplasma pneumonia
Drug reaction
Is HSP more common in girls or boys?
Boys
Erythema nodosum
Tender, discrete nodules on the shins
Erythema infectiosum
Slapped cheeck - parvovirus B19
Erythematous cheek progresses to maculopapular lace-like rash over trunj and limbs
Fever, malaise, headache, myalgia
How does PVB19 cause an aplastic crisis?
Infects erythroblastoid red cell precursors in the BM
- Paritcularly common in sickle cell
