Paediatrics Dermatology Flashcards
What is eczema?
Chronic atopic condition
Defects in continuity of skin barrier causing inflammation
Runs in families
When does eczema present?
Infancy with dry, red, itchy and sore patches on flexor surfaces
Comes in flares
What is the management of eczema?
Maintenance = emollients (thick and greasy - artificial barrier) after washing + before bed soap substitutes
Flares = thicker emollients, topical steroids (sometimes tacrolimus)
What are some specialist treatments in severe eczema?
Zinc impregnated bandages
Topical tacrolimus
Phototherapy
Systemic immunosuppressants (oral corticosteroids, methotrexate and azathioprine)
What are the thin creams and thick creams used in eczema?
Thin = E45, diprobase cream, oilatum cream, aveeno cream, cetraben cream, epaderm cream
Thick = 50:50 ointment (50% liquid parafen), hydromol ointment, diprobase ointment, cetraben ointment, epaderm ointment
What are the side effects of topical steroids?
Thinning of the skin = flares, bruising, tearing, stretch marks, enlarged blood vessels (telangiectasia)
What is the steroid ladder for steroid cream?
Mild: Hydrocortisone 0.5%, 1% and 2.5%
Moderate: Eumovate (clobetasone butyrate 0.05%)
Potent: Betnovate (betamethasone 0.1%)
Very potent: Dermovate (clobetasol propionate 0.05%)
What can treat bacterial infection of the skin in eczema? Which bacteria is most common?
Oral abx (flucloxacillin - if severe then IV)
Staphylococcus aureus
What is eczema herpeticum?
Viral skin infection caused by herpes simplex virus (HSV) ot varicella zoster virus (VZV)
What was eczema herpeticum previously known as?
Kaposi varicelliform eruption (don’t confuse with Kaposi’s sarcoma)
What is the most common organism in eczema herpeticum?
Herpes simplex virus 1 (coldsore)
Who does eczema herpeticum usually occur in?
Patients with pre-existing condition e.g. atopic eczema or dermatitis
How does eczema herpeticum present?
Widespread, painful vesicular rash
Fever, lethargy, irritability
Lymphadenopathy
Describe the rash in eczema herpeticum?
Widespreak, erythematous, painful, itchy, vesicles containing pus (burst and leave punched out lesions)
What is the management of eczema herpeticum?
Viral swabs of the vesicles to confirm diagnosis
Aciclovir (mild = oral, severe = IV aciclovir)
What are some complications of eczema herpeticum?
Can be life-threatening if not treated properly (in immunocompromised)
Bacterial superinfection
What is psoriasis?
Chronic autoimmune conditon causing psoriatic skin lesions
What causes psoriasis?
Genetic component (but not clear)
1/3 patients have first degree relative with psoriasis
Describe the patches of psoriasis?
Dry
Flaky
Scaly
Faintly erythematous
Raised
Rough plaques
EXTENSOR SURFACES
Why do psoriatic plaques occur?
Rapid generation of new skin cells causing
abnormal buildup and thickening of the skin
Name 4 types of psoriasis?
Plaque psoriasis
Guttate psoriasis
Pustular psoriasis
Erythrodermic psoriasis
Describe plaque psoriasis?
Thickened erythematous plaques
Silver scales
Exensor surfaces
Most common form of psoriasis
Describe guttate psoriasis?
Common in children
Many small raised papules across trunk and limbs
Mildly erythematous and slightly scaly
Triggered by streptococcal throat infection, stress or medications
Resolves spontaneously in 3-4 months
What is pustular psoriasis?
Rare severe form of psoriasis where pustules form under areas of erythematous skin
Pus is not infective
Systemically unwell - medical emergency
Describe erythrodermic psoriasis?
Rare and severe psoriasis
Erythematous inflamed areas on most of the surface of the skin
Skin comes away in large patches = raw exposed areas - medical emergency and requires admission
Which specific signs are suggestive of psoriasis?
Auspitz sign = small points of bleeding where plaques are scraped off
Koebner phenomenon = development of psoriatic lesions to areas of skin affected by trauma
Residual pigmentation = after lesions resolve
How is psoriasis diagnosed?
Clinical appearance of the lesions
What are the treatment options for psoriasis?
Topical steroids
Topical vitamin D analogues (calcipotriol)
Topical dithranol
Topical calcineurin inhibitors (tacrolimus) usually only used in adults
Phototherapy with narrow band ultraviolet B light for guttate psoriasis
Which unlicensed treatments can be used for difficult to control psoriasis?
Methotrexate
Cyclosporine
Retinoids
Biologic medication
Which products contain both a potent steroid and vitamin D analogue?
Dovobet
Enstilar
(not licensed in children)
What conditions are associated with psoriasis?
Nail psoriasis - pitting, thickening, discolouration, ridging and onycholysis (separation of the nail from nail bed)
Psoriatic arthritis - (10% of patients with psoriasis) within 10 years of developing skin changes
Psychological - depression and anxiety
Obesity, hyperlipidaemia, hypertension and type 2 diabetes
What causes acne?
Blocking of the pilesebaceous unit by increased production of sebum trapping keratin
Causing chronic inflammation with / without localised infection
What are the pilosebaceous unit?
Tiny dimples in skin containing hair follicles and sebaceous glands (produce natural skin oils and sebum)
Why is acne exacerbated by puberty / improving with anti-androgenic hormonal contraception?
Androgenic hormones increase the production of sebum
What are swollen and inflamed pilosebaceous units known as?
Comedones
What bacteria is thought to overgrow in acne?
Propionibacterium acnes (usually colonises the skin)
Define the following terms:
Macules
Papules
Pustules
Comedomes
Blackheads
Ice pick scars
Hypertrophic scars
Rolling scars
Macules = flat marks on the skin
Papules = small lumps on the skin
Pustules = small lumps containing yellow pus
Comedomes = skin coloured papules representing blocked pilosebaceous units
Blackheads = open comedones with black pigmentation in the centre
Ice pick scars = small indentations in the skin that remain after acne lesions heal
Hypertrophic scars = small lumps in the skin that remain after acne lesions heal
Rolling scars = irregular wave-like irregularities of the skin that remain after acne lesions heal
What is the management of acne?
Reduce symptoms / scarring / psychosocial impact
What medications can be used for acne?
No treatment if mild
Topical benzoyl peroxide to reduce inflammation (toxic to P. acnes bacteria)
Topical retinoids (chemical related to vit A) slow production of sebum
Topical abx e.g. clindamycin (prescribed with benzoyl peroxide to reduce bacterial resistance)
Oral abx e.g. lymecycline
Oral contraceptive pill to stabalised hormones and slow production of sebum
What is the last-line option for treating acne?
Oral retinoids i.e. isotretinoin (specialist prescribes) - careful follow up and monitoring
What is the most effective COCP for treating acne?
Co-cypindiol (Dianette) due to anti-androgen effects
Higher risk of thromboembolism so treatment is discontinued once acne is controlled
What is the oral isotretinoin called?
Roaccutane (retinoid)
How does roaccutane work?
Reduce production of sebum
Reduce inflammation
Reduce bacterial growth
What is the risk of roaccutane in women?
Teratogenic (harmful to foetus) patients must have effective and reliable contraception - must stop medication a month before becoming pregnant
What are some side effects of isotretinoin?
Dry skin and lips
Photosensitivity of the skin to sunlight
Depression and suicidal ideation (must be screened for mental health issues before starting treatment)
Rarely stevens-Johnson syndrome and toxic epidermal necrolysis
What is an exanthem?
Eruptive widespread rash
Name the original six “viral exanthemas”
First disease: Measles
Second disease: Scarlet Fever
Third disease: Rubella (AKA German Measles)
Fourth disease: Dukes’ Disease
Fifth disease: Parvovirus B19
Sixth disease: Roseola Infantum
What is measles caused by?
Measles virus - highly contagious via respiratory droplets
How and when do symptoms of measles start?
10 - 12 days after exposure
Fever, coryzal symptoms and conjunctivitis
What are Koplik spots?
Greyish-white spots on the buccal mucosa - pathognomic for measles
Describe the rash in measles?
Starts on the face behind the ears
3-5 days after the fever
Spreads to rest of body
Erythmatous, macular rash with flat lesions
What is the management of measles?
Self-resolves after 7-10 days of symptoms
Isolate until 4 days after symptoms resolve
Notifiable disease
30% develop complications
What are the complications of measles?
Pneumonia (most common cause of death)
Diarrhoea
Dehydration
Encephalitis
Meningitis
Hearing loss
Vision loss
Death
What is scarlet fever associated with?
Group A streptococcus infection, usually tonsillitis (not caused by a virus)
What is scarlet fever caused by?
Exotoxin produced by the strep pyogenes (group A strep) bacteria
Describe the rash in scarlet fever?
Red-pink, blotchy, macular rash with rough “sandpaper” skin - starts on the trunk and spreads outwards
What are the other features of scarlet fever?
Fever
Lethargy
Flushed face
Sore throat
Strawberry tongue
Cervical lymphadenopathy
What is the treatment of scarlet fever?
Abx for the underlying strep bacterial infection
Phenoxymethylpenicillin (penicillin V) for 10 days
Notifiable disease
Kept off school for 24 hours after starting abx
Which other conditions are associated with group A strep infection?
Post-streptococcal glomerulonephritis
Acute rheumatic fever
What is Rubella caused by? When do symptoms appear?
Rubella virus
2 weeks after exposure
Describe the rash in rubella?
Milder erythematous macular rash starting on face and spreading to rest of the body
How long does the rash last in rubella?
What are the associated symptoms?
3 dyas
Mild fever
Joint pain
Sore throat
Lymphadenopathy
What is the management of rubella?
Self-limiting
Notifiable disease
Stay off school for 5 days after rash disappears
Avoid pregnant women
What are the complications of rubella?
Thrombocytopenia
Encephalitis
Pregnancy = congenital rubella syndrome (deafness, blindness, congenital heart disease)
What is the fourth disease?
Dukes disease- mostly forgotten in clinical practice (no organism found to explain it)
Non-specific viral rash
What is the fifth disease also known as?
Parvovirus B19
Slapped cheek syndrome
Erythema infectiosum
What are the features of parvovirus infection?
Mild fever, coryza, non-specific viral symptoms e.g. muscle aches and lethargy
2-5 days after the rash appears (bright red, both cheeks, “slapped cheeks”
A few days after the reticular (net-like) erythematous rash appears which affects the trunks and limbs (raised and itchy)
How is parvovirus B19 managed?
Self-limiting
Rash / symptoms fade over 1-2 weeks
Supportive with fluids / analgesia
Infectious prior to rash but once formed, no longer infectious and can return
Who is at risk of complications to parvovirus?
Immunocompromised
Pregnant women
Haematological conditions (sickle cell anaemia, thalassaemia, hereditary spherocytosis and haemolytic anaemia)
How to manage patients with parvovirus and at risk of complications?
Serology testing to confirm diagnosis
FBC and reticulocyte count for aplastic anaemia
What are some complications of parvovirus infection?
Aplastic anaemia
Encephalitis or meningitis
Pregnancy complications including fetal death
Hepatitis, myocarditis or nephritis
What is the sixth disease? What causes it?
Roseola infantum
Human herpes virus 6 (HHV-6)
Human herpes virus 7 (HHV-7)
How does roseola progress?
1-2 weeks after infection with high fever (up to 40) suddenly lasting 3-5 days then disappearing
Coryzal symptoms, sore throat, lymphadenopathy
Fever settles and rash appears for 1-2 days
How does the rash appear in roseola?
Mild erythematous macular across arms, legs, trunk and face - is not itchy
Full recovery in a week- don’t generally need to be kept of nursery
What is the main complication of roseola?
Febrile convulsions due to high temperature
Immunocompromised = myocarditis, thrombocytopenia, Guillain-Barre syndrome
What is erythema multiforme?
Erythematous rash caused by hypersensitivity reaction
Caused by viral infections and medncations

Which infections are associated with erythema multiforme?
Herpes simplex virus
Mycoplasma pneumonia
How does erythema multiforme present?
Widespread, itchy, erythematous rash
Characteristic “target lesions” = red rings withing larger red rings - darkest red at centre
Stomatitis
Mild fever
Muscle
Joint aches
Headaches
Flu-like symptoms
What is the management of erythema multiforme?
Clinically diagnosed - on appearance of rash
Establish cause (e.g. coldsore or treatment with penicillin) CXR to look for mycoplasma pneumonia
If mild usually self-resolves within one to four weeks
Cases may be recurrent
How are severe cases of erythema multiforme managed?
Admit (especially where oral mucosa affected)
IV fluids
Analgesia
Steroids (systemic - use is contoversial / topical)
Abx / antivirals where infection is present
What are urticaria?
AKA hives
Small itchy lumps which appear on the skin
May be patchy erythematous rash (localised / widespread)
Associated angioedema and flushing
Can be acute or chronic
What is the pathophysiology of urticaria?
Release of histamine and other pro-inflammatory chemicals by mast cells in the skin
When is urticaria seen?
Allergic reaction
Acute urticaria
Autoimmune reaction
Chronic idopathic urticaria
What causes urticaria?
Something that stimulates the mast cells to release histamine e.g:
- Allergies to food, medication or animals
- Contact with chemicals, latex or stinging nettles
- Medications
- Viral infections
- Insect bites
- Dermatographism (rubbing of the skin)
What causes chronic urticaria?
Autoantibodies targetting mast cells, triggering them to release histamines
What are the sub categories of chronic urticaria?
Chronic idiopathic urticaria
Chronic inducible urticaria
Chronic autoimmune urticaria
What is chronic idiopathic urticaria?
Recurrent episodes of chronic urticaria without a clear underlying cause
What causes chronic inducible urticaria?
Chronic urticaria, triggered by:
- Sunlight
- Temperature change
- Strong emotions
- Hot or cold weather
- Pressure (dermatographism)
What is autoimmune urticaria?
Chronic uritcaria associated with an underlying autoimmune condition e.g. SLE
What is the treatment of urticaria?
Antihistamines: fexofenadine
Oral steroids for severe flares
If severe:
- Anti-leukotrienes e.g. montelukast
- Omalizumab which targets IgE
- Cyclosporin
What is chickenpox caused by?
Varicella zoster virus - highly contagious generalised vesicular rash
How does chickenpox present?
Widespread, erythematous, raised, vesicular (fluid filled), blistering lesions
Starts on trunk and spreads outwards affecting the whole body over 2-5 days
What are the other symtoms of chickenpox?
Fever
Itch
General fatigue and malaise
When is chickenpox contagious?
Highly contagious initially - spread through direct contact with lesions or through infected droplets (cough or sneeze)
Symptomatic 10 days - 3 weeks after exposure
Stop being contagious when all lesions have crusted over
What are some complications of chickenpox?
Bacterial superinfection
Dehydration
Conjunctival lesions
Penumonia
Encephalitis (presenting as ataxia)
Where does varicella zoster virus lie dormant? What can it reactivate as?
Sensory dorsal root ganglion cells
Shingles / Ramsay Hunt syndrome
What can be given to pregnant women who are not immune to VZV after exposure?
Varicella zoster immunoglobulins
What can chickenpox in pregnancy, before 28 weeks gestation cause?
Developmental problems in the foetus (congenital varicalle syndrome)
What can chickenpox in the mother around time of delivery cause?
Life threatening neonatal infection
Treated with varicella zoster immunoglobulins and aciclovir
When is medication considered for chickenpox? What is given?
Immunocompromised, adults, adolescents over 14 years presenting within 24 hours, neonates
Aciclovir
What can treat the itching in chickenpox?
Calamine lotion and chlorphenamine (antihistamine)
How long do lesions take to scab over in chickenpox?
5 days after rash appears
What causes hand, foot and mouth disease?
What is the incubation period?
Coxsackie A virus
Incubation is 3-5 days
How does hand, foot and mouth disease present?
Fever, anorexia, cough, sore throat, abdo pain
After 1-2 days small mouth ulcers appear followed by blistering red spotsacross the body (most notable on thehands,feet and mouth (also buttock, genitals and legs)
Rash may be itchy
How is hand, foot and mouth disease diagnosed?
Clinical appearance
What is the management of hand, foot and mouth?
Supportive - fluid and simple analgesia e.g. paracetamol
Resolves spontaneously after 7-10 days
Highly contagious - avoid sharing towels and bedding, careful handling of dirty nappies
What are the complications of hand, foot and mouth?
Dehydration
Bacterial superinfection
Encephalitis
What is molluscum contagiosum?
Viral skin infection caused by molluscum contagiosum virus - type of poxvirus
What are the features of molluscum contagiosum?
Small, flesh coloured papules with a characteristic central dimple
Appear in crops
How is molluscum contagiosum spread?
Direct contact or sharing items like bed towels or bed sheets
What is the treatment of the papules in molluscum contagiosum?
Resolve by themselves - without treatment - takes up to 18 months
Scratching should be avoided = spreading, scarring and infection
What is the management of molluscum contagiosum?
No change in lifestyle required - avoid sharing towels or close contact with lesions
What is the treatment if bacterial superinfection occurs in molluscum contagiosum?
Topical fuscidic acid
Oral flucloxacillin
When will specialist treatment be considered for molluscum contagiosum?
Immunocompromised
Lesions on eyelids / anogenital area
What are some specialist treatment options for molluscum contagiosum?
Topical potassium hydroxide, benzoyl peroxide, podophyllotoxin, imiquimod or tretinoin
Surgical removal and cyrotherapy (freezing with liquid nitrogen) - can lead to scarring
What is pityriasis rosea?
Generalised, self limiting rash of unknown cause occuring in adolescents and young adults (possibly caused by HHV-6 or HHV-7)
How does pityriasis rosea present?
Pro-drome before rash = headache, tiredness, loss of appetite and flu-like symptoms
Rash = herald patch (faint red, scaly, oval lesion - 2cm/ more diameter on torso) then 2 days after widespread pink, scaly, oval lesions 2cm/less - follows chrismas tree fashion, following lines of the ribs
(dark skinned = grey / lighter than skin lesions)
Other symptoms = generalised itch, low grade pyrexia, headache, lethargy
What is the disease course of pityriasis rosea?
Resolves without treatment within 3 months - can leave discolouration of skin where lesions were
What is the treatment of pityriasis rosea?
No treatment for rash - resolves spontaneously without any long term effects - not contagious
Symptomatics treatment for itching = emollients, topical steroids, sedating antihistamines (e.g. chlorphenamine) at night
What is seborrhoeic dermatitis?
Inflammatory skin condition affecting the sebaceous glands (oil producing glands) in the skin - affecting scalp. nasolabial folds, and eyebrows
Causing erythema, dermatitis and crusted dry skin
= cradle cap in infants
What is thought to colonise in seborrhoeic dermatitis?
Malassezia yeast (improves with anti-fungal treatment)
What is cradle cap also known as? How does it progress?
Infantile seborrhoeic dermatitis - self limiting - resolves by 4 months can last 12 months
What is the treatment for infantile seborrhoeic dermatitis?
Apply baby / vegetable / olive oil and gently brush scalp and wash off
White petroleum jelly can be used to soften the crusted aread overnight - washed off next morning
Topical anti-fungal cream e.g. clotrimazole or miconazole for 4 weeks
Referral to dermatologist
How does seborrhoeic dermatitis of the scalp present?
Flaky itchy skin (dandruff) or oily scaly brown crusting normally in adolescents
What is the treatment of seborrhoeic dermatitis of the scalp?
First line = ketoconazole shampoo (left on for 5 minutes before washing off)
Topical steroids if severe itching
Reoccurs after successful treatment
What is the treatment of seborrhoeic dermatitis of the face and body?
Anti-fungal cream e.g. clotrimazole / miconazole for up to 4 weeks
Topical steroids - localised inflammed areas e.g. hydrocortisone 1%
Severe cases refer to dermatologist
What is ringworm? What is it also known as?
Fungal infection of the skin
AKA tinea and dermatophytosis
Define the following terms:
Tinea capitis
Tinea pedis
Tinea cruris
Tinea corporis
Onychomycosis
Tinea capitis = ringworm affecting the scalp
Tinea pedis = ringworm affecting the feet
Tinea cruris = ringworm of the groin
Tinea corporis = ringworm on the body
Onychomycosis = fungal nail infection
Which fungus commonly causes ring worm?
Trichophyton - contact with infected individuals, animals or soil
How does ringworm present?
Itchy rash = erythmatous, scaly and well demarcated rings (fainter in middle)
How does tinea capitis present?
Well demarcated hair loss
Itching, dryness, erythema of scalp
More common in children than adults
How does tinea pedis (athletes foot) present?
White / red, flaky, cracked, itchy patches between toes (may split and bleed)
Occurs after sharing changing rooms with athletes foot, & when feet are sweaty and damp for long periods
How does onchomycosis (fungal nail infections) present?
Thickened, discoloured and deformed nails
How is ring worm diagnosed?
Clinically (can scrape off some scales and send for microscopy and culture - to confirm)
What is the treatment of ringworm?
Anti-fungal medication:
- Cream = clotrimazole and miconazole
- Shampoo = ketoconazole
- Oral = fluconazole, griseofulvin, itraconazole
What is the treatment of fungal nail infections?
amorolfine nail lacquer (6-12 months)
Resistant = oral terbinafine (need LFTs monitoring before and whilst taking)
What can be given for inflammation and itching in ringworm?
Mild topical steroids (common combination = miconazole 2% and hydrocortisone 1% - Daktacort)
What advice should be given to prevent spread and avoid recurrence?
- Loose clothing
- Keep area clean and dry
- Avoid sharing towels, clothing and bedding
- Seperate towel for tinea pedis
- Avoid scratching and spreading to other aread
- Wear clean, dry socks every day
What is tinea incognito?
- Extensive, less well recognised fungal skin infection
- Ringworm misdiagnosed as dermatitis and a topical steroid prescribed (improving itching and inflammation) accelerating growth of fungal infection by dampening the immune response in the area
When steroids stopped then itchy rash returns worse than previously (less recognisable as ringworm)
What is nappy rash?
Contact dermatitis (caused by friction and contact with urine / faeces)
Common between 9-12 months
Added infection with candida (fungus) or bacteria (staphylococcus / streptococcus)
What are some risk factors for nappy rash?
Delayed changing of nappies
Irritant soaps and vigorough cleaning
Poorly absorbent nappies
Diarrhoes
Oral abx predisponsing to candida infection
Pre-term infants
How does nappy rash present?
Sore, red, inflammed skin in nappy area
Spares the creases
A few red papules
Uncomfortable, itchy, infant will be distressed
Can lead to erosions and ulcerations
What would indicate candidal infection rather than simple nappy rash?
- In skin folds
- Larger, red macules
- Well demarcated scaly border
- Satellite lesions = small similar patches of rash or pustules near the main rash
- Oral thrush
What measures can be used to improve nappy nash?
- Highly absorbent nappies
- Change nappy after use
- Water / alcohol free products for cleaning area
- Ensure nappy area is dry before replacing
- Maximise time not wearing a nappy
What can be given for nappy rash infected with candida or bacteria?
Anti-fungal cream = clotrimazole or miconazole
Antibiotic = fuscidic acid cream / oral fluclox
What are some complications of nappy rash?
Candida
Cellulitis
Jacquet’s erosive diaper dermatitis
Perianal pseudoverrucous papules and nodules
What are scabies?
Mites called sarcoptes scabiei
Burrow under skin and lay eggs causing infection and itching
Up to 8 weeks for symptoms / rash to appear
How does scabies present?
Itchy, small red spots with track marks where the mites have burrowed - classically located between finger webs (can spread to whole body)
What is the treatment of scabies?
Permethrin cream (whole body - covering skin - 8-12 hours left on then washed off - repeat a week later for eggs that have hatched) - not after bath/shower so the cream stays on top of skin
Oral ivermectin - single dose which can be repeated a week later for difficult to treat / crusted scabies
Highly contagious and all household needs treating
Wash on hot all clothes / linen / towels to desroy the mites
Thorough hoovering also needed
Crotamiton cream and chlorphenamine at night can help with itching (can contine for 4 weeks after successful treatment)
What are crusted scabies (aka norwegian scabies)?
Scabies in immunocompromised patients - contagious - patches of red skin that turn into scaly plaques (misdiagnosed a psoriasis)
May have absent itchdue toimmune response to the infestation
Admit for treatment with oral ivermectin and isolation
What parasite causes head lice?
Pediculus humanus capitis parasite (commonly known as nits but these are egg shells which have hatched)
How are head lice spread?
Head to head contact or sharing combs or towels
How do headlice present?
Itchy scale (eggs / lice can be visible)
What is the management of head lice?
Dimeticone 4% lotion applied to hair and left to dry (8 hours overnight then washed off)
Repeat 7 days later to kill any lice that have hatched since
Special fine combs can be used to systematically comb the nits and lice out - can be used for detection combing after treatment (The Bug Buster Kit is recommended by NICE)
What are non-blanching rashes?
Rashes caused by bleeding under the skin
Define petechiae and purpura?
Petechiae = small (<3mm) non-blanching, red spots on the skin caused by burst capillaries
Purpura = larger (3-10mm) non-blanching, red-purple, macules or papules created by leaking of blood from vessels under skin
List the differentials for a non-blanching rash?
Meningococcal septicaemia (other baterial sepsis) = fever need emergency abx
Henoch-Schonlein purpura (HSP) = purpuric rash on legs and buttocks associated abdo / joint pain
Idiopathic thrombocytopenic purpura (ITP) = develops over several days in otherwise well child
Acute leukaemias = gradual development of petechiae (along with anaemia, lymphadenopathy and hepatosplenomegaly)
Haemolytic uraemic syndrome (HUS) = oliguria (very low urine output) and signs of anaemia - child with recent diarrhoea
Mechanical = strongh coughing, vomiting or breath holding = petechiae in SVC distribution above neck and prominently around eyes
Traumatic = tight pressure on skin e.g. non-accidental injury can cause traumatic petechiae
Viral illness = when other causes are excluded typical causes are influenza and enterovirus
Which investigations are there for non-blanching rashes?
FBC = anaemia (HUS/leukaemia) low WCC (neutropaemic sepsis / leukaemia) low platelets (ITP or HUS)
U&Es = high urea and creatinine indicates HUS or HSP with renal involvement
CRP = non-specific indication of inflammation / infection
ESR = non-specific indication of inflammatory illness e.g. vasculitis (HSP) or infection
Coagulation screen = PT, APTT, INR and fibrinogen for clotting abnormalities
Blood culture = useful but not definitive in diagnosing / excluding sepsis
Meningococcal PCR = confirms meningococcal disease, should not delay treatment
LP = diagnose meningitis / encephalitis
Blood pressure = HTN in HSP and HUS (hypotension in septic shock)
Urine dip = proteinuria and haematuria suggests HSP with renal involvement or HUS
What is the management of non-blanching rash?
Urgent referral and investigation (unless clear and unconcerning cause)
If in doubt then treat for meningococcal sepsis
What is erythema nodosum?
Red lumps appear across patients shins
What causes erythema nodosum?
Inflammation and the subcutaneous fat on the shins (hypersensitivity reaction - associated lots of conditions)
What is inflammation of fat called?
Panniculitis
What hypersensitivity reactions cause erythema nodosum?
- Strep throat infections
- Gastroenteritis
- Mycoplasma pneumoniae
- TB
- Pregnancy
- Medications e.g. oral contraceptive pill and NSAIDs
Which chronic diseases cause erythema nodosum?
IBD
Sarcoidosis
Lymphoma
Leukaemia
How does erythema nodosum present?
Red, inflamed, subcut nodules across both shins
Raised, painful and tender
What are the investigations for erythema nodosum?
Inflammatory markers (CRP and ESR)
Throat swab for strep infection
CXR for mycoplasma, TB, sarcoidosis and lymphoma
Stool microscopy and culture for campylobacter and salmonella
Faecal calprotectin for IBD
Further imaging / endoscopy under specialist guidance
What is the management of erythema nodosum?
Investigate for underlying condition
Conservatively with rest / analgesia
Steroids help settle inflammation
Mostly resolves in 6 weeks
What is impetigo?
Superficial bacterial skin infection usually caused by staphylococcus aureus bacteria - “golden crust” is characteristic
Strep pyogenes can also cause it
Contagious and children to be kept off of school during infection
How does impetigo occur? What is associated with it?
Bacteria enters via a break in the skin - may be associated with eczema or dermatitis
What are the types of impetigo?
Non-bullous or bullous
Where does non-bullous impetigo usually occur?
Around nose / mouth
Exudate from lesions dry to form golden crust
Do not usually cause systemic symptoms
What is the treatment for non-bullous impetigo?
Antiseptic cream (hydrogen peroxide 1% cream) first line
Topical fusidic acid treats localised
Oral flucloxacillin for more widespread (good for staph infections)
Advise no touching or scratching lesions, good hand hygiene, avoid sharing face towels and cutlery
Off school till all lesions healed / abx for at least 48 hours
What is bullous impetigo?
1-2cm fluid filled vesicles form on skin - burst = “golden crust”
Always caused by staphylococcus aureus bacteria - produce epidermolytic toxins which break down proteins that hold skin together
Heal without scarring
Painful and itchy
Who is bullous impetigo more common in?
Neonates and children under 2 years
How does bullous impetigo present?
More systemic symptoms e.g. feverish and generally unwell
What is severe bullous impetigo called?
Staphylococcus scalded skin syndrome
How to confirm diagnosis of bullous impetigo?
Swabs of the vesicles (confirm diaganosis, bacteria and abx sensitivities)
What is the treatment of bullous impetigo?
Abx usually flucloxacillin (orally / IV)
Isolate patients - condition is contagious
What are some complications of bullous impetigo?
Cellulitis if infection deepens in skin
Sepsis
Scarring
Post strep glomerulonephritis
Staphylococcus scalded skin syndrome
Scarlet fever
What is staphylococcal scalded skin syndrome (SSSS)?
Skin infection with staphylococcys aureus which produces epidermolytic toxins (protease enzymes which break down proteins that hold skin cells together)
Who does SSSS typically affect?
Children under 5 years (older children = immunity to epidermolytic toxins)
How does SSSS present?
Generalised patches of erythema (thin and wrinkled)
Formation of bullae (burst and leave sore, erythematous skin) appears like burn / scald
What sign is positive in SSSS?
Nikolsky sign - gentle rubbing of skin causes it to peel away
What are the systemic symptoms in SSSS?
Fever
Irritability
Lethargy
Dehydration
(If untreated can lead to sepsis and potentially death)
What is the management of SSSS?
Admission and treatment with IV abx
Fluid / electrolyte balance as prone to dehydration
Adequate treatment then full recovery without scarring
What are Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) both?
Spectrum of same pathology where disproportional immune response causes epidermal necrosis resulting in blistering and shedding of the top layer of skin
SJS = less than 10% body surface area
TEN = more than 10%
Usually drug related
Which medications can cause Stevens-Johnson syndrome?
Anti-epileptic
Antibiotics
Allopurinol
NSAIDs
Which infections cause SJS?
Herpes simplex
Mycoplasma pneumonia
Cytomegalovirus
HIV
How does SJS / TEN present?
Mild / severe - lifethreatening
Non-specific symptoms = fever, cough, sore throat, sore mouth, sore eyes and itchy skin
Rash develops (purple/red) across skin and blisters
Skin breaks away and leaves raw tissue underneath (on eyes, lips and mucous membranes too)
Can also affect urinary tract, lungs and internal organs
What is the management of SJS and TEN?
Medical emergency - burns unit
Supportive - nutrition, antiseptics, analgesia, ophthalmology
Steroids, immunoglobulins and immunosuppressants
What are some complications of SJS or TEN?
Secondary infection - breaks in skin = cellulitis and sepsis
Permanent skin damage - scarring, damage to skin, hair, lungs and genitals
Visual complications - sore eyes to blindness