Dermatology

Question 1

What is eczema?

Answer 1

a chronic atopic condition caused by defects in the normal continuity of the skin barrier, leading to inflammation in the skin

Question 2

How does eczema present in infancy?

Answer 2

with dry, red, itchy and sore patches of skin over the flexor surfaces (the inside of elbows and knees) and on the face and neck

Question 3

What is done to maintain eczema?

Answer 3

Involves creating an artificial barrier over the skin to compensate for the defective skin barrier. This is done using emollients that are as thick and greasy as tolerated, used as often as possible, particularly after washing and before bed.

Patients should avoid activities that break down the skin barrier, such as bathing in hot water, scratching or scrubbing their skin and using soaps and body washes that remove the natural oils in the skin. Emollients or specifically designed soap substitutes can be used instead of soap and body washes when showering or washing hands.

Avoiding triggers - temperature, dietary, washing powder, emotions, stress

Question 4

Management of eczema flares?

Answer 4

treated with thicker emollients, topical steroids, “wet wraps” (covering affected areas in a thick emollient and applying a wrap to keep moisture locked in overnight) and treating any complications such as bacterial or viral infections. Very rarely IV antibiotics or oral steroids might be required in very severe flares.

Question 5

What is specialist treatment for severe eczema?

Answer 5

zinc impregnated bandages, topical tacrolimus, phototherapy and systemic immunosuppressants, such as oral corticosteroids, methotrexate and azathioprine.

Question 6

Examples of thin and thick emollients?

Answer 6

Thin creams:

E45
Diprobase cream
Oilatum cream
Aveeno cream
Cetraben cream
Epaderm cream
Thick, greasy emollients:

50:50 ointment (50% liquid paraffin)
Hydromol ointment
Diprobase ointment
Cetraben ointment
Epaderm ointment

Question 7

Describe the steroid ladder, from weakest to most potent:

Answer 7

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%)

Question 8

What is the most common organism causing bacterial skin infection in eczema?

Answer 8

Staph aureus

Question 9

Treatment of bacterial skin infection in eczema

Answer 9

Treatment is with oral antibiotics, particularly flucloxacillin. More severe cases may require admission and intravenous

Question 10

What is eczema herpeticum?

Answer 10

a viral skin infection caused by the herpes simplex virus (HSV) or varicella zoster virus (VZV). It was previously known as Kaposi varicelliform eruption

Question 11

What is the most common causative organism of eczema herpeticum?

Answer 11

Herpes simplex virus 1 (HSV-1)

may be associated with a coldsore in the patient or a close contact

Question 12

Who is at risk of eczema herpeticum?

Answer 12

patient with a pre-existing skin condition, such as atopic eczema or dermatitis, where the virus is able to enter the skin and cause an infection.

Question 13

Presentation of eczema herpeticum?

Answer 13

A typical presentation is a patient who suffers with eczema that has developed a widespread, painful, vesicular rash with systemic symptoms such as fever, lethargy, irritability and reduced oral intake. There will usually be lymphadenopathy (swollen lymph nodes).

Question 14

What is the rash like in eczema herpeticum?

Answer 14

• widespread
• affect any area of the body
• erythematous
• painful
• sometimes itchy
• with vesicles containing pus
• after they burst - leave small punched-out ulcers with red base

Question 15

Management of eczema herpeticum?

Answer 15

Viral swabs of the vesicles can be used to confirm the diagnosis, although treatment is usually started based on the clinical appearance.

Treatment is with aciclovir. A mild or moderate case may be treated with oral aciclovir, whereas more severe cases may require IV aciclovir.

Question 16

Complications of eczema herpeticum?

Answer 16

Children with eczema herpeticum can be very unwell. When not treated adequately it can be a life threatening condition, particularly in patients that are immunocompromised.

Bacterial superinfection can occur, leading to a more severe illness. This needs treatment with antibiotics.

Question 17

Presentation of chickenpox?

Answer 17

Chickenpox is characterised by widespread, erythematous, raised, vesicular (fluid filled), blistering lesions. The rash usually starts on the trunk or face and spreads outwards affecting the whole body over 2 – 5 days. Eventually the lesions scab over, at which point they stop being contagious.

Other symptoms:

Fever is often the first symptom
Itch
General fatigue and malaise

Question 18

How infectious is chickenpox?

Answer 18

Chickenpox is highly contagious and spread through direct contact with the lesions or through infected droplets from a cough or sneeze. Patients become symptomatic 10 days to 3 weeks after exposure. They stop being contagious after all the lesions have crusted over.

Question 19

Complications of chickenpox?

Answer 19

Bacterial superinfection
Dehydration
Conjunctival lesions
Pneumonia
Encephalitis (presenting as ataxia)
After the infection the virus can lie dormant in the sensory dorsal root ganglion cells and cranial nerves reactivate later in life as shingles or Ramsay Hunt syndrome.

Question 20

Management of chickenpox?

Answer 20

Chickenpox is usually a mild self limiting condition that does not require treatment in otherwise healthy children.

Aciclovir may be considered in immunocompromised patients, adults and adolescents over 14 years presenting within 24 hours, neonates or those at risk of complications.

Complications such as encephalitis require admission for inpatient management.

Symptoms of itching can be treated with calamine lotion and chlorphenamine (antihistamine).

Patients should be kept off school and avoid pregnant women and immunocompromised patients until all the lesions are dry and crusted over. This is usually around 5 days after the rash appears.

Question 21

What microorganism causes hand, foot, and mouth disease?

Answer 21

Coxsackie A virus

Question 22

Incubation period of hand, foot, and mouth disease?

Answer 22

3-5 days

Question 23

Presentation of hand, foot and mouth disease?

Answer 23

The illness starts with typical viral upper respiratory tract symptoms such as tiredness, sore throat, dry cough and raised temperature.

After 1 – 2 days small mouth ulcers appear, followed by blistering red spots across the body. As the name suggests, these spots are most notable on the hands, feet and around the mouth. Painful mouth ulcers, particularly on the tongue are also a key feature. The rash may be itchy.

Question 24

Management of hand, foot and mouth disease?

Answer 24

Diagnosis is made based on the clinical appearance of the rash.

There is no treatment for hand, foot and mouth disease. Management is supportive, with adequate fluid intake and simple analgesia such as paracetamol if required. The rash and illness resolve spontaneously without treatment after a week to 10 days

It is highly contagious and advice should be give about measures to avoid transmission, such as avoiding sharing towels and bedding, washing hands and careful handling of dirty nappies.

Question 25

Complications of hand, foot and mouth disease?

Answer 25

Rarely it can cause complications:

Dehydration
Bacterial superinfection
Encephalitis

Question 26

What is Molluscum contagiosum?

Answer 26

viral skin infection caused by the molluscum contagiosum virus, which is a type of poxvirus

Question 27

Features of Molluscum contagiosum?

Answer 27

Molluscum contagiosum is characterised by small, flesh coloured papules (raised individual bumps on the skin) that characteristically have a central dimple. They typically appear in “crops” of multiple lesions in a local area. It is spread through direct contact or by sharing items like towels or bedsheets.

The papules resolve by themselves without any treatment, however this can take up to 18 months. Once they resolve the skin returns to normal. Scratching or picking the lesions should be avoided as it can lead to spreading, scarring and infection.

Question 28

Management of Molluscum contagiosum?

Answer 28

No treatment or change in lifestyle is required and children can continue all their normal activities. They should avoid sharing towels or other close contact with the lesions to minimise the risk of spreading the infection. Usually just simple reassurance and education is enough.

Rarely, if bacterial superinfection infection occurs in the lesions as a result of scratching, this may require treatment with antibiotics. Options include topical fuscidic acid or oral flucloxacillin.

Immunocompromised patients and those with very extensive lesions or lesions in problematic areas such as the eyelid or anogenital area may require referral to a specialist. Specialist treatment options include:

Topical potassium hydroxide, benzoyl peroxide, podophyllotoxin, imiquimod or tretinoin
Surgical removal and cryotherapy (freezing with liquid nitrogen) is an option but can lead to scarring

Question 29

What is nappy rash?

Answer 29

contact dermatitis in the nappy area. It is usually caused by friction between the skin and nappy and contact with urine and faeces in a dirty nappy

Additionally, the breakdown in skin and the warm moist environment in the nappy can lead to added infection with candida (fungus) or bacteria, usually staphylococcus or streptococcus.

Question 30

Risk factors for nappy rash?

Answer 30

Delayed changing of nappies
Irritant soap products and vigorous cleaning
Certain types of nappies (poorly absorbent ones)
Diarrhoea
Oral antibiotics predispose to candida infection
Pre-term infants

Question 31

Presentation of nappy rash?

Answer 31

Nappy rash present with sore, red, inflamed skin in the nappy area. The rash appears in individual patches on exposure areas of the skin that come in contact with the nappy. It tends to spare the skin creases, meaning the creases in the groin are healthy. There may be a few red papules beside the affected areas of skin. Nappy rash is uncomfortable, may be itchy and the infant may be distressed. Severe and longstanding nappy rash can lead to erosions and ulceration.

Question 32

What signs point to candidate infection rather than simple nappy rash?

Answer 32

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
Check for oral thrush with a white coating on the tongue, as this is likely to indicate a fungal infection in the nappy area.

Question 33

Management of nappy rash?

Answer 33

Simple measures can be taken to improve skin health and treat nappy rash within a few days:

Switching to highly absorbent nappies (disposable gel matrix nappies)
Change the nappy and clean the skin as soon as possible after wetting or soiling
Use water or gentle alcohol free products for cleaning the nappy area
Ensure the nappy area is dry before replacing the nappy
Maximise time not wearing a nappy
Infection with candida or bacteria warrants treatment with an anti-fungal cream (clotrimazole or miconazole) or antibiotic (fusidic acid cream or oral flucloxacillin).

Question 34

Complications of nappy rash?

Answer 34

Candida infection
Cellulitis
Jacquet’s erosive diaper dermatitis
Perianal pseudoverrucous papules and nodules

Question 35

Management of head lice?

Answer 35

Dimeticone 4% lotion can be applied to the hair and left to dry. This is left on for 8 hours (i.e. overnight), then washed off. This process is repeated 7 days later to kill any head lice that have hatched since treatment.

Special fine combs can be used to systematically comb the nits and lice out of the hair. They can be used for detection combing to check the success of treatment. NICE clinical knowledge summaries recommend The Bug Buster kit.

Question 36

What is impetigo?

Answer 36

a superficial bacterial skin infection, usually caused by the staphylococcus aureus bacteria.

A “golden crust” is characteristic of a staphylococcus skin infection. It is also less commonly caused by the streptococcus pyogenes bacteria. Impetigo is contagious and children should be kept off school during the infection.

Impetigo occurs when bacteria enter via a break in the skin. This may be in otherwise healthy skin or may be related to eczema or dermatitis.

can be classified as non-bulbous or bullies

Question 37

What is non-bullous impetigo?

Answer 37

Non-bullous impetigo typically occurs around the nose or mouth. The exudate from the lesions dries to form a “golden crust”. They are often unsightly but do not usually cause systemic symptoms or make the person unwell.

Question 38

Treatment for non-bullous impetigo?

Answer 38

Topical fusidic acid can be used to treat localised non-bullous impetigo. Draft NICE guidelines from August 2019 suggest using antiseptic cream (hydrogen peroxide 1% cream) first line rather than antibiotics for localised non-bullous impetigo.

Oral flucloxacillin is used to treat more wide spread or severe impetigo. Flucloxacillin is the antibiotic of choice for staphylococcal infections.

Advise about measure to avoid spreading the impetigo. Patients should be given advice about not touching or scratching the lesions, hand hygiene and avoiding sharing face towels and cutlery. They need to be off school until all the lesions have healed or they have been treated with antibiotics for at least 48 hours.

Question 39

What is bullous impetigo?

Answer 39

Bullous impetigo is always caused by the staphylococcus aureus bacteria. These bacteria can produce epidermolytic toxins that break down the proteins that hold skin cells together. This causes 1 – 2 cm fluid filled vesicles to form on the skin. These vesicles grow in size and then burst, forming a “golden crust”. Eventually they heal without scarring. These lesions can be painful and itchy.

This type of impetigo is more common in neonates and children under 2 years, however it can occur in older children and adults. It is more common for patients to have systemic symptoms. They may be feverish and generally unwell. In severe infections when the lesions are widespread, it is called staphylococcus scalded skin syndrome.

Question 40

Treatment of bullous impetigo?

Answer 40

Swabs of the vesicles can confirm the diagnosis, bacteria and antibiotic sensitivities. Treatment of bullous impetigo is with antibiotics, usually flucloxacillin. This may be given orally or intravenously if they are very unwell or at risk of complications. The condition is very contagious and patients should be isolated where possible.

Question 41

Complications of impetigo?

Answer 41

Impetigo usually responds well to treatment without any long term adverse effects. Rarely there can be complications:

Cellulitis if the infection gets deeper in the skin
Sepsis
Scarring
Post streptococcal glomerulonephritis
Staphylococcus scalded skin syndrome
Scarlet fever

Question 42

What is staphylococcal scalded skin syndrome?

Answer 42

is a condition caused by a type of staphylococcus aureus bacteria that produces epidermolytic toxins. These toxins are protease enzymes that break down the proteins that hold skin cells together. When a skin infection occurs and these toxins are produced, the skin is damaged and breaks down. This condition usually affects children under 5 years. Older children and adults have usually developed immunity to the epidermolytic toxins.

Question 43

Presentation of staphylococcal scalded skin syndrome?

Answer 43

SSSS usually starts with generalised patches of erythema on the skin. Then the skin looks thin and wrinkled. This is followed by the formation of fluid filled blisters called bullae, which burst and leave very sore, erythematous skin below. This has a similar appearance to a burn or scald.

Nikolsky sign is where very gentle rubbing of the skin causes it to peel away. This is positive in SSSS.

Systemic symptoms include fever, irritability, lethargy and dehydration. If untreated it can lead to sepsis and potentially death.

Question 44

Management of staphylococcal scalded skin syndrome?

Answer 44

Most patients will require admission and treatment with IV antibiotics. Fluid and electrolyte balance is key to management as patients are prone to dehydration. When adequately treated, children usually make a full recovery without scarring.

Question 45

Summary of a strawberry naevus?

Answer 45

usually not present at birth but may develop rapidly in the first month of life. They appear as erythematous, raised and multilobed tumours.

increase in size until around 6-9 months before regressing over the next few years (around 95% resolve before 10 years of age).

Common sites include the face, scalp and back. Rarely they may be present in the upper respiratory tract leading to potential airway obstruction

Female infants, premature infants and those of mothers who have undergone chorionic villous sampling are more likely to be affected

Potential complications
mechanical e.g. Obstructing visual fields or airway
bleeding
ulceration
thrombocytopaenia

If treatment is required (e.g. Visual field obstruction) then propranolol is increasingly replacing systemic steroids as the treatment of choice. Topical beta-blockers such as timolol are also sometimes used. External compression therapy, topical steroids, topical antiseptics/antibiotics

Cavernous haemangioma is a deep capillary haemangioma

Question 46

Summary of milia?

Answer 46

small, benign, keratin-filled cysts that typically appear around the face. They may appear at any age but are more common in newborns.

Retention of keratin in dermis, dead skin cells get trapped under skin + form cysts

Resolve spontaneously

Question 47

Summary of Erythema toxicum neonatorum (baby acne)?

Answer 47

Common benign condition
Flushed + more red when warm

Red blotches, macules, papules, central white pustule
Present at birth or <48hrs can be as late as 2 wks

Resolves after 1 wk

Question 48

What is miliaria?

Answer 48

a common disorder of the eccrine sweat glands that often occurs in conditions of increased heat and humidity

heat rash/prickly heat

1° stimuli: conditions of high heat, humidity XS sweating

Miliaria crystallina: transient sweat pore disruption or immaturity. Ductal disruption is sup in stratum corneum. Tiny, fragile clear vesicles, peak at 1 wk.

Miliaria rubra: surrounding flush like prickly heat rash. Obstruction deeper in epidermis + pruritic erythemaout papules

Question 49

Summary of ‘strork bite’?

Answer 49

salmon patches

vascular birthmark which can be seen in around half of newborn babies

pink and blotchy, and commonly found on the forehead, eyelids and nape of the neck.

They usually fade over a few months, though marks on the neck may persist.

Question 50

What is nappy rash/napkin dermatitis?

Answer 50

an acute inflammatory reaction of the skin in the nappy area, which is most commonly caused by an irritant contact dermatitis

The skin barrier function can be compromised by skin maceration, friction, prolonged skin contact with urine and faeces, and resultant increased skin pH.

Complications include secondary infection with Candida and bacteria such as Staphylococcus aureus and streptococci.

Risk factors include the skin cleaning regime, type of nappy, use of baby wipes and other topical preparations, and recent diarrhoea or antibiotic use.

Question 51

Features of nappy rash?

Answer 51

Well-defined areas of confluent erythema and scattered papules over convex surfaces in contact with the nappy (the buttocks, genitalia, suprapubic area, and upper thighs), with sparing of the inguinal skin creases and gluteal cleft.

There may be skin erosions, oedema, and ulceration if there is severe involvement.

Child distressed, agitated, uncomfortable

Question 52

Management of nappy rash?

Answer 52

Skin swab for C&S If 2’ infection suspected

Advise parents - nappy with high absorbency, leaving nappies off for as long as possible, changing nappy frequently and ASAP after soiling, using water or fragrance free baby wipes, drying gently, avoid irritants

barrier preparation - if mild erythema and asymptomatic - sudocrem

topical hydrocortisone 1% OD if causing discomfort

topical imidazole if rash persists or candida suspected

oral abs - rash persists, bacterial infection suspected

Question 53

What is impetigo?

Answer 53

a superficial bacterial skin infection usually caused by either Staphylcoccus aureus or Streptococcus pyogenes.

It can be a primary infection or a complication of an existing skin condition such as eczema, scabies or insect bites.

Impetigo is common in children, particularly during warm weather.

Spread is by direct contact with discharges from the scabs of an infected person

incubation period is between 4 to 10 days.

Question 54

Features of impetigo?

Answer 54

‘golden’, crusted skin lesions typically found around the mouth

very contagious

Question 55

Management of impetigo?

Answer 55

hydrogen peroxide 1% ceram - limited localised disease

topical antibiotic creams - topical fusidic acid, topical mupirocin, if MRSA then topical mupirocin

extensive disease - oral flucloxacillin, or oral erythromycin

school exclusion - children should be excluded from school until the lesions are crusted and healed or 48 hours after commencing antibiotic treatment