Paeds - Dermatology

Question 1

Acne Vulgaris

Pathophysiology
Risk Factors/Modifiers
Clinical Features
General Management/Advice

Answer 1

1. ) Pathophysiology
   - androgens trigger ↑sebum and comedone formation
   - sebum and comedones causes blockage of pilosebaceous ducts which leads to inflammation
   - pilosebaceous glands mostly on face, back, chest
2. ) Risk Factors/Modifiers
   - hormonal: menstrual cycle, PCOS, other endo disor…
   - oil-based cosmetics
   - drugs: steroids (both types), lithium, cyclosporin, oral iodides (can be part of homoeopathic therapies)
   - stress and diet have little effect on acne vulgaris
   - UV light can actually benefit acne
3. ) Clinical Features - greasy skin, excoriation
   - mild: comedones (non-inflammatory) which can be either whitehead (closed) or blackheads (open)
   - moderate: inflammatory (papules, pustules, nodules)
   - severe: atrophic/ice-pick scars, hypertrophic/keloid scars, hyperpigmentation
4. ) General Management/Advice
   - avoid over-cleaning, acne is not due to poor hygiene
   - use a non-alkaline detergent cleansing product BD
   - avoid oil-based products e.g. make-up, sunscreen
   - avoid persistent picking or scratching as –> scarring
   - not enough evidence to support specific diets

Question 2

Management of Acne Vulgaris

Mild/Comedonal to Moderate/Inflammatory Acne
Moderate to Severe
Referral to Dermatology
Severe/Scarring

Answer 2

1. ) Mild/Comedonal to Moderate/Inflammatory Acne
   - mild: adapalene or BPO, OR epiduo (has both)
   - moderate: epiduo or duac (BPO + clindamycin)
   - review each treatment after every 12wks
2. ) Moderate to Severe - or not responding to above
   - combine oral antibiotics with a topical combination^^
   - Abx: lymecycline or doxycycline OD –> BD
   - clarithromycin used in <12 or pregnancy
   - oral abx used for 3 mths, maximum 6 if still clearing
   - the COCP can be an alternative or alongside
3. ) Referral to Dermatology
   - severe: visible/risk of scarring or hyperpigmentation
   - moderate acne only partially responding to treatment
   - psychological distress regardless of physical signs
4. ) Severe/Scarring - start on treatment above and referral to dermatology for treatment w/ isotretinoin
   - isotretinoin (Roaccutane) is an oral retinoid
   - side effects: teratogenic, dry skin, lips, eyes, fragile skin, alopecia, photosensitivity, deranged LFTs, epistaxis, ↑triglycerides, myalgia, arthralgia, depression/suicide, intracranial hypertension
   - monitoring: U+Es, LFTs, appropriate contraception (co-prescribed two forms of contraception)

Question 3

Atopic Eczema/Dermatitis

Pathophysiology
Triggers
Clinical Features
Assessing Severity

Answer 3

1. ) Pathophysiology - primary defect in the skin barrier function due to mutation of filaggrin gene
   - immunological changes secondary to ↑ antigen penetration through a deficient epidermal barrier
   - often presents in childhood but most grow out of it
   - personal or family history of atopy is very common
2. ) Triggers - can cause spontaneous flare-ups
   - stress, skin infection, soap/detergent, rough clothes
   - winter: central heating drying out skin
   - specific triggers: animal dander/saliva, food, pollen house-dust mites
3. ) Clinical Features
   - itchy, erythematous, scaly, papulovesicular rash
   - dry skin, excoriations –> lichenification
   - distribution: poorly defined, face and trunk in infants, extensors in younger kids, flexures in older kids
   - can be diagnosed using a patch test
4. ) Assessing Severity
   - mild: dry skin, infrequent itching +/- areas of redness
   - moderate: dry skin, frequent itching, redness +/- excoriation and localized skin thickening
   - severe: widespread dry skin, itchy+++, redness w/ bleeding, oozing, cracking, hyperpigmentation
   - infected: weeping/crusted, or pustules w/ fever

Question 4

Management of Atopic Eczema

General Advice
Mild Eczema
Moderate Eczema
Severe Eczema

Answer 4

1. ) General Advice
   - avoid triggers: e.g. clothing, soaps, animals, heat
   - avoid scratching, rub area w/ fingers to alleviate itch
   - use anti-scratch mittens for babies with eczema
   - ointments are more suitable for night-time use
2. ) Mild Eczema
   - emollients: continuous and generous usage
   - mild topical corticosteroids for flare-ups
3. ) Moderate Eczema - as above including:
   - moderate topical corticosteroids for flare-ups
   - use mildly potent if in face, flexures, genitals, or axilla
   - maintenance therapy to prevent recurrent flare-ups: use weaker topical steroid twice a week
   - occlusive dressing and dry bandages
   - PO antihistamines: severe itch/urticaria, non-sedating (Cetirizine) or sedating if can’t sleep (chlorphenamine)
4. ) Severe Eczema - as above including:
   - potent topical steroids for flare ups, moderate potency if in sensitive area e.g. face, genitals
   - topical calcineurin inhibitors: steroid-sparing agents, proptic (tacrolimus) pr elidel (pimecrolimus)
   - PO prednisolone 30mg OD-1w if eczema causing psychological distress

Question 5

Medications for Chronic Skin Conditions

Acne Medication
Emollients
Potentcies of Topical Corticosteroids
Usage of Topical Corticosteroids

Answer 5

1. ) Acne Medication
   - treatments may irritate the skin, especially at the start
   - start w/ short-contact application (wash off after 1hr)
   - Adapalene: topical retinoid only
   - Epiduo: contains adapalene and benzoyl peroxide
   - Duac: contains benzyl peroxide and clindamycin
2. ) Emollients - a mixture of fats and water, rehydrates skin and re-establishes the surface lipid layer
   - lotion (least greasy) –> cream –> ointment (greasiest)
   - use >2-4 times a day, apply ASAP after washing
   - wait 15-30 minutes before applying other topicals
   - pump dispensers ↓risk of bacterial contamination
3. ) Potencies of Topical Corticosteroids
   - potencies: Help Every Budding Dermatologist
   - mild: Hydrocortisone 0.5/1%, moderate: Eumovate
   - potent: Betnovate, very potent: Dermovate
   - potent/very potent not used on the face or genitals
   - v potent only be prescribed by dermatologists
4. ) Usage of Topical Corticosteroids
   - fingertip units (FTU) are used for measurement, different areas of the body require different FTUs
   - in eczema, use for 48hrs after the flare is controlled
   - in psoriasis, don’t use >8w in one site, should have a 4w treatment break where vitD is continued

Question 6

Nappy Rash

Pathophysiology
Clinical Features
Differential Diagnosis
Practical Advice
Treatment

Answer 6

1. ) Pathophysiology - irritant contact dermatitis in the nappy area caused by friction and contact with urinary ammonia and faeces in a dirty nappy
   - very very common, most between 9-12mths of age
   - the breakdown in skin and warm moist environment can lead to infection w/ candida or strep/staph
2. ) Clinical Features
   - sore, red, inflamed skin in the nappy area, there may be a few red papules beside the affected areas of skin
   - usually spares the skin creases and flexures
   - may be distressed as it is uncomfortable and itchy
   - severe/prolonged rash –> erosions and ulcerations
   - candida infection: involves skin folds, scaly borders, circular patterns, satellite lesions, oral thrush
   - seborrhoeic dermatitis: rash with flakes
3. ) Differential Diagnosis
   - allergic contact dermatitis, atopic eczema, psoriasis
   - if the rash persists or becomes moist w/ white or red pimples in skin folds, it may be an infection instead
   - streptococcal or seborrhoeic dermatitis
4. ) Practical Advice - should resolve in 3 days
   - use nappy with high absorbency e.g. disposable gel matrix nappies compared to non-disposable nappies
   - clean and change nappy every 3-4hrs
   - leave nappies off as long as possible to help dry skin
   - apply barrier cream (e.g. Zinc and castor oil)
   - avoid irritants such as soap or bubble baths
5. ) Treatment - if baby is in distress and rash is inflamed
   - hydrocortisone 1% cream once a day for up to 7 days
   - candida: topical imidazole, stop barrier creams

Question 7

Chicken Pox (varicella-zoster virus )

Pathophysiology
Clinical Features
Management
Complications

Answer 7

1. ) Pathophysiology - primary infection with VZV
   - incubation is 10-21 days, spread via respiratory route
   - highly infectious: 4 days before the rash, until 5 days after the rash first appeared (vesicles dry/crusted over)
   - can be caught from shingles (reactivation of the dormant virus in a dorsal root ganglion)
2. ) Clinical Features
   - fever initially for 2 days before developing a rash
   - rash: clusters of itchy erythematous vesicles starting on the torso and face then becoming widespread
   - macular –> papular –> vesicular –> scabbed vesicles
   - other sx: malaise, headache, nausea, myalgia
3. ) Management - self-limiting
   - topical calamine lotion to bathe the lesions
   - paracetamol for flu-like symptoms, avoid aspirin (Reye’s) and ibuprofen (↑risk of necrotising fasciitis)
   - keep cool, adequate fluid intake, trim nails
   - return to school only when vesicles are crusted over
   - VZIG in immunocompromised and newborns with peripartum exposure, IV aciclovir if chickenpox develops
4. ) Complications
   - necrotising fasciitis: secondary infection of blisters
   - encephalitis, cerebellar ataxia, pneumonia, myocarditis

Question 8

Measles (First Disease)

Infection
Clinical Features
Management
Complications

Answer 8

1. ) Infection - rubeola virus (first disease)
   - incubation period is 10-12 days, highly contagious
   - spreads via droplets from the mouth or nose
   - infective 4 days before and 5 days after the rash
2. ) Clinical Features
   - prodromal phase: high fever, unilateral conjunctivitis, rhinitis (coryza), cough, irritability, malaise
   - koplik spots: white/grey spots in the buccal mucosa, typically appears before the rash
   - rash: confluent. maculopapular, begins behind the ears then becomes widespread
   - desquamation that typically spares the palms and soles may occur after a week
3. ) Management
   - self-limiting: takes around a week to resolve
   - rest, hydration, simple analgesia
   - notify local health protection team and PHE
   - receive testing kits to confirm cases (oral sample)
   - avoid school/work for >4days after the rash appears
4. ) Complications
   - encephalitis –> subacute sclerosing panencephalitis
   - transient hepatitis, otitis media, diarrhoea
   - bronchopneumonia, croup
   - stillbirth or miscarriage if during pregnancy

Question 9

Scarlet Fever (Second Disease)

Pathophysiology
Clinical Features
Management
Complications

Answer 9

1. ) Pathophysiology - reaction to toxins produced by Group A haemolytic streptococci (usually S. pyogenes)
   - peak incidence in children aged 4 (2-6 range)
   - respiratory spread: inhaling, ingesting, direct contact
   - incubation of 2-4 days
2. ) Clinical Features
   - fever (lasting 24-48hrs), malaise, headache, N+V
   - sore throat, strawberry tongue, cervical lymphadenopathy
   - rash: fine punctate coarse ‘sandpaper-like’ rash, starting on the torso and sparing the palms and soles, but more intense in the cubital fossa
   - flushed appearance with circumoral pallor
   - desquamation occurs later in the course of the illness, particularly around the fingers and toes
3. ) Management
   - a throat swab is taken for a definitive diagnosis but you treat with abx before waiting for the results
   - oral penicillin V (or azithromycin) for 10 days
   - children can return to school 24hrs after starting abx
   - scarlet fever is a notifiable disease
4. ) Complications
   - otitis media: the most common complication
   - rheumatic fever: often occurs 20 days after infection
   - acute glomerulonephritis: 10 days after infection
   - invasive complications (e.g. bacteraemia, meningitis, necrotizing fasciitis) are rare but life-threatening)

Question 10

Kawasaki Disease

Pathophysiology
Clinical Features
Investigations
Management

Answer 10

1. ) Pathophysiology - rare, systemic, medium-sized vessel vasculitis with no clear cause or trigger
   - affects children typically <5yrs, more common in boys and in Asian children (particularly Japanese)

2.) Clinical Features
- persistent high fever (>39ºC) for more than 5 days
- widespread erythematous maculopapular rash and desquamation (skin peeling) on the palms and soles
- other features: strawberry tongue, cracked lips,
cervical lymphadenopathy, bilateral conjunctivitis
- children will be unhappy and unwell

3. ) Investigations
   - FBC (↓Hb ↑WCC, ↑plts), ↑CRP, ↑ESR
   - LFTs: hypoalbuminemia and elevated liver enzymes
   - urinalysis: can show raised WBCs without infection (sterile pyuria)
   - ECHO: can demonstrate coronary artery pathology
4. ) Management
   - high dose aspirin to reduce the risk of thrombosis
   - single dose of IVIG to reduce risk of coronary artery aneurysms
   - close follow up with echocardiograms to monitor for evidence of coronary artery aneurysm

Question 11

Erythema Infectiosum (Parvovirus 19, Fifth Disease, Slapped Cheek Syndrome)

Clinical Features
Management
Childhood Exanthems

Answer 11

1. ) Clinical Features
   - fever, headache, rhinorrhoea
   - rash: erythema, maculopapular, on cheeks +/- trunk
2. ) Management - self limiting
   - fluids, analgesia, rest
   - minimise spread while symptomatic however, usually not infectious 1 day after the rash appears
3. ) Childhood Exanthems - viruses causing red rashes
   - others: measles (1st), scarlet fever (2nd), rubella (3rd)

Question 12

Roseola Infantum (Sixth Disease)

Pathophysiology
Clinical Features
Management

Answer 12

1. ) Pathophysiology - viral exanthem (sixth disease) caused by the human herpesvirus 6 (HHV6)
   - incubation period is 5-15 days
   - typically affects children aged 6 months to 2 years
2. ) Clinical Features
   - sudden high fever (up to 40ºC) lasting 3-5 days
   - may have coryzal sx during the illness such as a sore throat, cough, and swollen lymph nodes
   - rash appears for 1-2 days once the fever settles
   - mild erythematous (rose pink) maculopapular rash across the arms, legs, trunk and face, it is not itchy
   - Nagayama spots: papular enanthem on the uvula and soft palate
3. ) Management - self-limiting (within a week)
   - school exclusion is not needed
   - febrile convulsions are common due to the high fever

Question 13

Hand, Foot, and Mouth Disease

Pathophysiology
Clinical Features
Management

Answer 13

1. ) Pathophysiology - caused by the intestinal viruses most commonly coxsackie A16 and enterovirus 71
   - incubation period is usually 3-5 days, very contagious and typically occurs in outbreaks at nursery
2. ) Clinical Features
   - typically starts with viral URTI symptoms such as fever, tiredness, sore throat, dry cough
   - mouth ulcers (can be painful) appear after 1-2 days
   - blistering red vesicles then develop on the palms of the hands and soles of the feet and around the mouth
3. ) Management - self-limiting after 7-10 days
   - general advice about hydration and analgesia
   - avoid transmission: avoid sharing towels, bedding, wash hands and careful handling of dirty nappies
   - reassurance no link to disease in cattle
   - children do not need to be excluded from school
   - complications (rare): dehydration, bacterial superinfection, encephalitis

Question 14

Impetigo

Clinical Features
Causes and Risk Factors
Management

Answer 14

1. ) Clinical Features - bacterial infection
   - commonly due to S.aureus but can also be caused by S.pyogenes
   - thin-walled vesicles releasing exudate, usually around the mouth and nose
   - bullous impetigo also contains bullae
2. ) Causes and Risk Factors
   - poor nutrition, crowding, contact sports, diabetes
   - breaks in skin: insect bites, scabies, eczema, herpes
3. ) Management
   - non-bullous: topical hydrogen peroxide for 5 days
   - bullous/severe: oral flucloxacillin for 5 days
   - stay away from school/work until lesions are dry

Question 15

Headlice

Pathophysiology
Diagnosis
Management

Answer 15

1. ) Pathophysiology - aka pediculosis capitis or ‘nits’
   - small insects that live in human hair that lay eggs (grey/brown, size of pinhead) glued to hair
   - nits are white/shiny empty egg shells
   - spread by direct head-to-head contact
2. ) Diagnosis
   - itching and scratching occurs 2-3wks after infection
   - diagnosed with fine-toothed combing of wet or dry hair to visualise live head lice
   - differentials: dandruff, seborrheic dermatitis, eczema
3. ) Management
   - 1°wet combing: using shampoo and conditioner, comb through hair for 10-30mins every 3 days for 2 wks, if still present after 17 days, seek advice from GP
   - other treatments: Hedrin (dimeticone), isopropyl myristate, cyclomethicone
   - not to do w/ poor hygiene, no need to wash linen
   - children do not need to stay off school

Question 16

Threadworms

Pathophysiology
Clinical Features
Management

Answer 16

1. ) Pathophysiology - infestation with Enterobius vermicularisis after swallowing eggs that are present in the environment e.g. in soil or outdoors
   - extremely common amongst children in the UK
2. ) Clinical Features - often asymptomatic in 90%
   - perianal itching, particularly at night which may lead to difficulty sleeping
   - girls may have vulval symptoms
3. ) Management
   - most patients are treated empirically with a:
   - single dose of PO mebendazole (anti-helminth) for children >6 months and the entire household
   - a single dose is given unless the infestation persists
   - can be diagnosed by applying Sellotape to the perianal area and sending for microscopy to see eggs