Paediatric dermatology Flashcards
What is the most common cause of a bacterial skin infection in someone with eczema ?
- Staphylococcus aureus
what is eczema herpeticum ?
- Viral skin infection caused by HSV or VZV
How does eczema herpeticum present ?
- Pt who suffers with asthma
- Develops widespread, painful, vesicular rash
- Systemic Sx : fever, lethargy, irritability, reduced oral intake
- Lympadenopathy
How is eczema herpeticum managed ?
- Aciclovir (Oral or IV depending on severity)
What is acne vulgaris characterised by ?
- Obstruction of the pilosebaceous follicle with keratin plugs resulting in comedones, inflammation and pustules
what is the stepwise approach to managing acne
- Topical benzoyl peroxide
- Topical retinoids (e,g,
- Topical Abx (e.g. clindamycin)
- Oral Abx (e.g. lymecycline)
- Oral contraceptive pill (co-cyprindiol)
- Severe : oral retinoids (Isotretinoin)
How does oral isotretinoin (roaccutane) work and a key CI?
- Reduces : sebum production, bacterial growth and inflammation.
- Teratogenic ! Must be stopped for at least 1mnth before getting pregnant.
4 SE of isotretinoin
- Dry skin and lips
- Photosensitivity of the skin to sunlight
- Depression, anxiety, aggression and suicidal ideation.
- Rarely Stevens-Johnson syndrome and toxic epidermal necrolysis
what are the 6 viral exanthemas
- Pathogens that cause an eruptive widespread rash
- Measles
- Scarlet fever
- Rubella
- Duke’s disease
- Parvovirus B19
- Roseola infantum
-> Fever and conjunctivitis, followed by:
-> Greyish white spots of buccal mucosa (Koplik)
-> Rash beginning behind the ears, before spreading to the rest of the body
Measles
8 complications of measles
Otitis media (Most common)
Pneumonia (Most common cause of death)
Diarrhoea
Dehydration
Encephalitis
Meningitis
Hearing loss
Vision loss
How long should children with measles be isolated for ?
Until 4 days after symptoms resolve
what is the cause of scarlet fever?
- Exotoxin produced by streptococcus pyogenes
What is the presentation of scarlet fever ?
- Initial tonsilitis
- Macular rash with ‘sandpaper’ feel, starting on trunkand spreading outwards.
- Flushed face
- Sore throat
- Strawberry tongue
- Cervical lymphadenopathy
How is scarlet fever managed
- 10 days of phenoxymethypenicillin (penicillin V)
How long should children with scarlet fever be kept off school ?
24 hours after staring antibiotics
Give 3 complications of scarlet fever
- Otitis media: the most common complication
- Rheumatic fever: typically occurs 20 days after infection
- Acute glomerulonephritis: typically occurs 10 days after infection
How does rubellapresent
- Prodrome : e.g. low-grade fever
- Rash: maculopapular, initially on the face before spreading to the whole body, usually fades by the 3-5 day
- Lymphadenopathy: suboccipital and postauricular
How long should children with Rubella be kept off school
5 days after rash appears
How does parvovirus B19 present ?
- Initial fever and coryzal Sx
- Diffuse bright red rash on both cheeks
- Raised and itchy rash spreading to trunk and limbs
Give 4 complications of parvovirus B19
- Aplastic anaemia
- Encephalitis or meningitis
- Pregnancy complications : fetal death
- Rarely hepatitis, myocarditis or nephritis
what is the cause of roseola infantum ?
Human herpes virus 6 (HHV6)
How does roseola infantum present
- High fever (40) : lasting a few days, followed later by :
- Maculopapular rash
- Nagayama spots: papular enanthem on the uvula and soft palate
what is the most common complication of roseola infantum ?
Febrile convulsions
what is erythema multiforme and what is it most commonly caused by ?
- Erythematous rash caused by a hypersensitivity reaction
- Viral infections and medications
What is a characteristic sign of erythema multiforme ?
-> Target lesions : red rings within larger red rings with the darkest point at the centre.
what is urticaria and 6 acute causes
- Hives (small itchy lumps) caused by release of histamines
- Allergies to food, medications or animals
- Contact with chemicals, latex or stinging nettles
- Medications
- Viral infections
- Insect bites
- Dermatographism (rubbing of the skin)
what are 3 chronic causes of urticaria ?
- Chronic idiopathic urticaria : unknown trigger
- Chronic inducible urticaria : specific trigger
- Autoimmune urticaria : caused by underlying autoimmune conditions (e.g. SLE)
what is the first line management of urticaria ?
Non sedating antihistamines (e.g. Fexofenadine)
what is the cause of chickenpox?
Varicella zoster virus (VZV)
what are 6 complications of chickenpox ?
- Bacterial superinfection (Increased risk with NSAIDs)
- Dehydration
- Conjunctival lesions
- Pneumonia
- Encephalitis (presenting as ataxia)
- Reactivation : Shingles, Ramsay Hunt syndrome
what is the cause of hand, foot and mouth disease ?
Coxsackie A virus
How does hand, foot and mouth disease present ?
- Mild systemic upset: sore throat, fever
- Oral ulcers
- Followed later by vesicles on the palms and soles of the feet
What is the cause of molluscum contagiosum ?
- Molluscum contagiosum virus (MCV) -> member of Poxviridae family
how does molloscum contagiosum present ?
- Pinkish or pearly white papules with a central umbilication
- Appear in clusters anywhere on the body (except hands and soles of feet)
what advice is given regarding molloscum contagiosum ?
- Usually self resolves within 18mnths
- Very contagious : avoid sharing towels, clothing etc
How does pityriasis rosea present ?
- Usually affects adolescents and young adults
- No prodrome : minority may give a history of a recent viral infection
- Herald patch (usually on trunk)
- Followed by : erythematous, oval, scaly patches. On the torso can be arranged in Christmas tree fashion following the ribs
How does seborroeic dermatitis often present in infants?
- Craddle cap : crusted flaky scalp
- Can also affect the nappy area, face and limb flexures
How is seborroeic dermatitis of the scalp managed ?
-> Infantile : Baby oil and gently brushing scalp. If not effective = white petroleum jelly overnight to soften crusted areas.
-> Dandruff : Ketoconazole shampoo
How is seborreic dermatitis of face and body managed
- 1st line = antifungal (clotrimazole, miconazole).
what is ringworm (Tinea) and what is the most common cause
- Fungal infection of the skin
- Trichophyton
what are the different kinds of ringworm ?
- Tinea capitis : ringworm affecting the scalp
- Tinea pedis : ringworm affecting the feet (athletes foot)
- Tinea cruris : ringworm of the groin
- Tinea corporis : ringworm on the body (corporis
- Onychomycosis : fungal nail infection
How is tinea infection managed
- Anti-fungal creams such as clotrimazole and miconazole
- Anti-fungal shampoo such as ketoconazole for tinea capitis
- Oral anti-fungal medications such as fluconazole, griseofulvin and itraconazole
How are fungal nail infections managed ?
- Amorolfine nail lacquer for 6-12 mnths
what signs would point towards a candidal infection, rather than a simple nappy rash ?
- Rash extending into the skin folds
- Larger red macules
- Well demarcated scaly border
- Circular pattern to the rash spreading outwards, similar to ringworm
- Satellite lesions, which are small similar patches of rash or pustules near the main rash
- Presence of oral thrush
How does scabies present ?
- Intensely itchy small red spots with possible track marks where the mites have burrowed
- Rash is often between the finger webs
How is scabies managed ?
- Permethrin cream
How are headlice treated ?
- Dimeticone 4% lotion overnight : repeated 7 days later
- Fine comb treatment
GIve 8 differentials of a non blanching rash
- Meningococcal septicaemia or other bacterial sepsis : presents with a feverish unwell child.
- Henoch-Schonlein purpura (HSP) : presents as a purpuric rash on the legs and buttocks and may have associated abdominal or joint pain.
- ITP : develops over several days in an otherwise well child.
- Acute leukaemias : gradual development of petechiae, potentially with other signs such as anaemia, lymphadenopathy and hepatosplenomegaly.
- Haemolytic uraemic syndrome (HUS): associated with oliguria (very low urine output) and signs of anaemia. This often presents in a child with recent diarrhoea.
-Mechanical: Strong coughing, vomiting or breath holding can produce petechiae in a “superior vena cava distribution”, above the neck and most prominently around the eyes. - Traumatic: Tight pressure on the skin, for example in non-accidental injury, or occlusion of blood in an area of skin can lead to traumatic petechiae.
- Viral illness: This is often the explanation when other causes and serious illness are excluded.
what is erythema nodosum
- Inflammation of subcutaneous fat
- Typically affecting the shins
Possible underlying causes of erythema nodosum
- Infection : streptococci, TB, brucellosis
- Systemic disease : sarcoidosis, IBD, Behcet’s
- Malignancy/lymphoma
- Drugs : penicillins, sulphonamides, combined oral contraceptive pill
- Pregnancy
what is impetigo ?
- Superficial bacterial skin infection
- Usually caused by staphylococcus aureus
what is non bullous impetigo and how is it managed
- Lesions occur around nose and mouth with ‘golden crusts’
- Hydrogen peroxide 1% cream
what is bullous impetigo and how is it managed ?
- Always caused by staph aureus
- Fluid filled vesicles that burst to form ‘golden crust’
- More systemically unwell
what is the treatment of pityriasis rosea ?
non indicated
Self limiting over 12 wks
What is pityriasis versicolor and how does it present ?
- Superficial cutaneous fungal infection
- Affects the trunk
- Pink or brown patches
- Mild itching
How is pityriasis versicolor managed ?
- Topical antifungal
- Ketonazole shampoo
