Dermatology Flashcards
Eczema, urticaria, neonatal rashes, infant rashes, rash + fever, infections, rashes of systemic disease
Atopic eczema course
Onset often in first 12m (after 2m)
1/3 develop asthma
75% resolve by 16y
Atopic eczema CF
Infants mostly face/scalp/trunk, older children mostly flexor surfaces + friction surfaces e.g. neck
CF: pruritus - excoriations - erythema, weeping, crusted lesions, lichenification
-regional lymphadenopathy in exacerbations
Exacerbation causes: bacterial infection (usually S aureus), viral (e.g. HSV-less common but can cause an extensive vesicular reaction eczema herpeticum which is an emergency), heat/humidity, ingestion of an allergen e.g. egg
Management of atopic eczema
- Avoid irritants like soap, biological detergents, pure wool clothes - prob have to try different things
- Could trial dietary eliminations to common allergens like egg/cow milk. For 4-6w to see response, dietician adv
- Cut nails to reduce scratching, mittens at night in young
- Emollients - liberal application at least 2x per day + after bath; in bath to use as a soap (still cleans just doesn’t foam), ointment better for night as more moisture but greasy
- Topical steroids: mild (1% hydrocortisone), stronger for acute exacerbations e.g. eumavate (moderate)/betnovate (potent)/dermovate (v potent). Don’t do unnecessarily but obviously if child needs it then they need it
- Immunomodulators for >2yo: e.g. topical tacrolimus
- Infections: topical/oral Abx + hydrocortisone depend on severity; eczema herpeticum need systemic acyclovir
- Itch suppression - oral non-sedating antihistamines
Urticaria
Activation of mast cells - mediators like histamine. If involves deeper tissues - angioedema
- Acute: viral infection (rash for days) or allergy (rash for hours, risk of anaphylaxis)
- Chronic idiopathic: intermittent for at least 6w, usually non-allergenic
- Physical: to cold, delayed pressure, heat, solar, cholinergic (from sweating), exercise, NSAIDs/aspirin
M: non-sedating antihistamines (may need high dose), refractory cases LTRA or anti-IgE antibody (omalizumab) used
Milia
Small pearly/yellow papule on babies
normal, last a few weeks
due to keratin + sweat glands not being fully formed
Erythema toxicum neonatorum
harmless rash on day 2-3 neonate, goes by 1w
small firm yellow/white pustules on top of erythematous skin, pus contains eosinophils
anywhere except pals + soles
Naevus simplex - stork bite marks
distended dermal capillaries - usually fade
Cradle cap
common, harmless, no itching (if symptoms consider atopic dermatitis) - large greasy yellow-brown scales on scalp/ears/face/nappy area/skin folds
usually clear on own, massaging scalp with baby oil will help loosen
Strawberry naevus
cavernous haemangiomas
RF: female, low birth weight, prematurity, multiple gestations
Port-wine stain
vascular malformation causing superficial dermal capillary ectasia
usually on face, pink/red/purple patches, tend to persist + darken with age
laser if disfiguring
Mongolian blue spot
Call slate grey naevi now!!
Blue/black pigmented lesions on buttocks/base of spine (trapped melanocytes in dermis)
more common in Afro-Caribbean or Asian babies
Fade in first few fews
Irritant contact dermatitis
commonest cause of nappy rash
cf: W-shaped lesion (spares folds, whereas other things affect folds), lower abdo/top of thighs, erythematous, may look scalded. if severe can have erosions/ulcers
made worse with baby wipes + cloth diapers as reduced absorption (so more contact with the irritant urine/poop), humidity, friction
m: keep area clean + dry, zinc oxide ointments??, emollients, if severe mild topical steroids.
not using a nappy would help but they obviously need to
Perineal candidiasis
Widespread erythematous sharply-bordered area, satellite papules/vesicules
often d’td over anterior perineum + perianal region
triggers include systemic abx
m: gentle cleansing, anti fungal e.g. nystatin (usually topical)
Molluscum contagiosum
Caused by DNA poxvirus
CF: small skin-coloured pearly papule with central umbilication, usually multiple, may occur in clusters. may be pruritic or tender or asymptomatic
M: usually go on their own over about a year, may use cryo in older children
Effect of prematurity on the skin
thin skin poorly keratinised higher transepidermal water loss impaired thermoregulation as less SC fat cannot sweat until a few weeks old
Bullous impetigo
blistering impetigo usually due to S aureus
m: systemic abx like fluclox
Large melanocytic naevi
may need excision due to risk of MM
Albinism
types: oculocutaneous, ocular or partial
Cf: depigmented skin, lack of fixation reflex due to lack of pigment in iris+retina, frowning due to nystagmus + photophobia, severe visual impairment
Epidermolysis bullosa
genetic conditions, rare, cause spontaneous blistering of skin + mucus membranes (or after mild trauma
AR versions may be fatal, AD version usually milder
m: avoid minor trauma, treat infections , maintain nutrition (like when oral ulcers), analgesia
Collodion baby
a rare type of ichthyosis (inherited itchy skin conditions)
cf: dry scaly skin, born with a taut shiny membrane, risk of dehydration, membrane then fissures + separates within a few weeks leaving either dry thickened skin or normal skin
m: emollients
infantile seborrheic dermatitis
this means an eruption of unknown cause in the first 3m
cf: erythematous scaly eruption forming a thick yellow layer (cradle cap), may spread to face/behind ears/flexures/nappy area, not itchy
higher risk of atopic eczema
m: emollients, ointment with sulphur + salicylic acid to wash it off, mild topical corticosteroid if widespread
Causes of maculopapular rashes (flat + bumpy)?
- Viral: roseala infantum, slapped cheek syndrome, measles, rubella
- Bacterial: scarlet fever, erythema marginatum, erythema migrans, typhoid fever
- Other: Kawasaki, JIA
Roseola infantum
HSV 6/7, usually children<2y
cf: sudden onset high fever (a/w sore throat, coryza, mild diarrhoea), temp reduces then generalised macular/maculopapular rash (mostly on trunk + neck), may get cervical lymphadenopathy
Slapped cheek syndrome
aka fifth disease, caused by parvovirus B19, usually school aged children
CF: mild prodrome, then bright red erythema on cheeks (sparing nose + periorbital/perioral areas), then over days/weeks it fades leaving a reticulated lacy pattern
Comps: adult version can cause arthralgia/arthritis (kids usually fine), can predispose aplastic crisis, in fetus can cause hydrops
Measles
V contagious virus (RNA paramyxovirus) with 7-10d incubation
cf: prodrome of coryza/sore red eyes/high fever, morbilliform rash (means looks like measles: macules, 2-10mm diameter, may be confluent, generalised + widespread, not itchy, often starts behind ears then to whole body), Koplik spots (blue-white spots in buccal mucosa before rash). starts to fade after about 4d, goes purple-brown colour then goes
IgM antibodies detected within a few days of rash onset
m: supportive, notifiable disease
comps: otitis media (most common), giant cell pneumonia, bacterial pneumonia, tracheitis, febrile convulsions, encephalitis (1-2w after onset), subacute sclerosing pan-encephalitis (v rare may happen 5-10y after illness), febrile convulsions, corneal ulceration/keratoconjunctivitis, diarrhoea, hepatitis, myocarditis
Rubella
average lasts 5d
incubation 14-21d, aerosol transmission
cf: erythematous rash, pink-light red macules 2-10mm, often asymptomatic, young children may have mild constitutional sx/coryza, older children/adults can get joint pains/thrombocytopenic purpura. most cases cause pre-auricular + occipital lymphadenopathy, after rash skin may flake, sometimes can get palatal petechiae in prodromal phase
Scarlet fever
group A haemolytic strep, aerosol/direct transmission
cf: pharyngitis, headache, high fever, flushed cheeks, bright red strawberry tongue, 12-72h after fever get fine red rough rash, fades after 3-4d then desquamation (peeling)
m: pen V, notifiable disease
comps: rheumatic fever, glomerulonephritis, erythema nodosum
What is the skin manifestation of rheumatic fever?
Erythema marginatum
Skin manifestation of Lyme disease?
Erythema migrans
What bacteria may cause rose spots?
Salmonella typhi (typhoid fever)
Kawasaki disease?
CRASH (Conjunctivitis, Rash, Adenopathy, Strawberry tongue, Hands and feet) and BURN (fever)
Herpes simplex infections
HSV1 - usually enters via MM/skin
may be asymptomatic
CF:
- gingivostomatitis (commonest primary infection): vesicles on lips/gums/anterior tongue/hard palate – painful ulcers, high fever, can last 2w
- skin: cold sores on lip margin (recurrent, may get infected), herpetic whitlow, eczema herpeticum
- CNS: encephalitis, meningitis
Chickenpox?
Varicella zoster virus, aerosol + direct transmission, incubation 10-21d
cf: fever, then rash on face/torso/scalp then rest of body (vesicles + erythematous halo then central umbilication + crusting), rash lasts 5-10d. severe cases can affect mucosa (more likely in adults)
m: usually supportive but immunocompromised kids given IV aciclovir/oral valaciclovir
* avoid NSAIDs - increases risk of necrotising fasciitis
* paracetamol for fever/pain
* topical camomile lotion to soothe itch
* sedating e.g. chlorphenamine/non-sedating e.g. loratidine/cetirizine antihistamines
comps: secondary bacterial infection, encephalitis (good prognosis), cerebellitis ~a week after rash causing cerebellar signs for about a month
Hand foot + mouth disease?
caused by coxsackie virus or enteroviruses, usually kids <10y
cf: high fever/cough/pharyngitis/stomach ache, oral lesions (red spots – yellow/grey ulcers), then spots on hands + soles that turn into blisters. lasts 7-10d
Causes of petechial/purpuric rashes?
- Viral: common for any esp adenovirus + enteroviruses
- Bacterial: meningoccal (80% with meningocci in blood get rash, may initially erythematous/maculopapular), infective endocarditis
- HSP
- Thrombocytopenia
- Vasculitis
- Malaria
Impetigo
Localised v contagious staph/strep skin infection
CF: lesions on face/neck/hands, erythematous macules, may become vesicular/pustular/bullous - rupture of vesicles - confluent honey-colour crusted lesions
M: topical Abx for mild e.g. muciporin, systemic Abx for more severe like flucloxacillin (tastes really bad) or co-amoxiclav (tastes better + simpler admin, but broad spec).
Avoid school/nursery until lesions dry (as the fluid is super infectious)
Periorbital cellulitis
Fever, erythema, tender + oedema of eyelid/skin near eye
Unilateral
May be from trauma/spread from sinuses/dental abscess
M: IV Abx high dose like ceftriaxone (as posterior spread—orbital cellulitis)
Comp: orbital cellulitis - proptosis, limited movement, reduced visual acuity (may lead to abscess, meningitis, cavernous sinus thrombosis)
Boils
Infection of hair follicle or sweat gland with S aureus
M: systemic Abx, surgical drainage sometimes
Staphylococcal scalded skin syndrome
Rare but serious, separation of epidermal skin due to an exfoliative staphylococcal toxin
Typically infants/young children
CF: fever + malaise, purulent crusting, tender, localised or widespread. epidermis separates o gentle pressure (Nikolsky skin), skin dries + heals without scarring
M: IV Abx e.g. fluclox + Abx + monitor fluid balance
Necrotising fasciitis
Rare severe SC infection - planes from skin down to fascia + muscle, enlarges rapidly - poorly perfused necrotic areas - severe pain + systemic illness
Often S aureus +/- anaerobic
M: debridement + IV Abx
Fungal skin infections
ringworm: dermatophyte fungi invade dead keratinous structures like the horny layer of ksin/naisl/hair
tinea capitis: scalp ringworm, causes scaling + patchy alopecia
Scabies
mite burrows into epidermis - severe itching
cf: burrows, papule, vesicles; varied distribution (older people finger webs and axillae/around penis or nipples; younger children often on palms/soles/trunk)
M: treat whole household with permethrin cream below neck to all areas and wash off after 8-12h (in babies on face + scalp too obv not eyes)
comps: secondary bacterial infection from scratching (crusted pustular lesions), secondary urticarial/eczematous rash
Pediculosis?
headlice
cf: itching scalp/nape, see live lice or nits (empty egg cases, which stay attached as the hair grows)
m: wet combing with fine tooth comb for at least 2d, insecticide shampoos + lotion
Psoriasis
Guttate psoriasis commonest in kids - after strep/viral ENT infection
CF: small raindrop/oval erythematous scaly patches over trunk + upper limbs, lasts 3-4m then usually recurs
Chronic psoriasis less common in kids
Pityriasis rosea
Acute benign condition, prob viral origin
CF: single round/ovals scaly macule 2-5cm diameter on trunk/upper arm/neck/thigh (Herald patch), then after a few days multiple smaller dull pink macules (follow line of the ribs posteriorly-fir tree pattern)
may itch but no treatment needed and goes in 4-6w
Granuloma annulare
Annular lesions with raised flesh-coloured edge (not scaled like ringworm), usually over bony prominences
Usually disappear but may take years
Rashes caused by systemic disease?
- facial rash in SLE/dermatomyositis
- purpura in HSP
- erythema nodosum: often no cause, or strep/TB/IBD/drug/sarcoid (rare in kids). tender nodules over legs
- erythema multiforme: target lesions with a central papule surrounded by ertyheamtosu ring. causes: idiopathic, HSV, Mycoplasma pneumonia, drug reaction
- stevens johnson syndrome
Causes of nappy rash
- Irritant/contact dermatitis (commonest)
- Candida infection: may cause or complicate it. Erythematous + includes flexures + satellite lesions. M-topical anti fungal
- Atopic eczema
- Rare things like langerhans cell histiocytosis, Wiskott-Aldrich syndrome
Features of HSP?
- Prodrome: headache, anorexia, fever
- Rash: usually on legs/buttocks as erythematous macular/urticarial lesions that turn into blanching papule and palpable purpura, usually symmetrical
- Joints: swollen, tender, painful (warmth, effusions + erythema are not characteristics of HSP)
- Sub cut oedema
- Haematuria
Verrucae?
These are viral warts of the soles/fingers, caused by HPV
most takes months-years to go, only treat if painful, can try daily salicylic acid paint etc or cryotherapy
Acne vulgaris
Can occur before puberty from adrenergic stimulation of sebaceous glands - more sebum - obstructed flow - inflammation
CF: open comedones (blackhead), closed comedones (whitehead), papule, pustules, nodules, cysts, scarring
m: topical to encourage peeling with keratolytic like benzoyl peroxide, topical abx/retinoids, oral abx when >12 with tetracycline/erythromycin, oral isotretinoin for severe in teenagers
