Dermatology

Question 1

What are the causes of nappy rash?

Answer 1

• Irritant dermatitis (inflammation of the skin due to contact with urine and faeces)
• Candida infection

Question 2

How can you differentiate between nappy rash caused by irritant dermatitis and candida infection clinically?

Answer 2

Irritant dermatitis:
- Rash spares the flexures

Candida infection:
- Rash includes the flexures

Question 3

Describe the management of nappy rash due to irritant dermatitis

Answer 3

Mainly conservative:

• Leave nappy off as much as possible
• Change nappy often

Medical:

• Use a thin layer of barrier cream/ointment before putting on each nappy, e.g. metanium
• Steroid cream/ointment, e.g. hydrocortisone

Question 4

Describe the management of nappy rash caused by candida infection

Answer 4

Topical antifungal treatment: an imidazole cream (e.g. clotrimazole, miconazole)

Question 5

When does infantile seborrhoeic dermatitis present?

Answer 5

Usually in the first few weeks of life

Question 6

Describe the clinical presentation of infantile seborrhoeic dermatitis

Answer 6

• Initially appears as erythematous, scaly rash on the scalp
• Then forms a thick yellow adherent layer (‘cradle cap’)
• Rash may spread to the face, behind the ears, flexural surfaces (e.g. axillae) and nappy area
• Does not bother baby

Question 7

Describe the management of infantile seborrhoeic dermatitis

Answer 7

Mild cases (conservative management):

• Parental reassurance, advise that rash will clear on its own
• Can use emollient/baby shampoo and gentle brushing to soften and loosen the scales

Moderate/severe cases (i.e. widespread involvement)
- Imidazole cream (e.g. clotrimazole, miconazole)

Question 8

Describe the aetiology of molloscum contagoisum

Answer 8

Poxvirus

Question 9

Describe the skin lesions found in molloscum contagiosum

Answer 9

• Small, skin-coloured pearly papules with central umbilication
• Usually widespread

Question 10

Describe the prognosis of molloscum contagiosum

Is it contagious?

Answer 10

• Self-limiting
• Treatment not usually recommended
• It is very contagious (spread directly through close personal contact, and indirectly through towels, flannels etc.)

Question 11

What are the clinical features of eczema?

Answer 11

• Dry, red, itchy patches of skin
• Infants: face and trunk
• Younger children: extensor surfaces
• Older children a more typical distribution is seen, with flexor surfaces affected and the creases of the face and neck

Question 12

Describe the management of eczema (maintenance and flares)

Answer 12

Maintenance management:
- Emollient, emollient, emollient!

Flares:

• Emollient
• Topical steroids (use lowest potency required for shortest time required)
• Dressings/bandages

Question 13

What are the potential complications of eczema?

Answer 13

• Eczema herpeticum (viral infection)

- Secondary bacterial infection

Question 14

Describe the aetiology of eczema herpeticum

Answer 14

Viral skin infection caused by HSV1

Question 15

What are the clinical features of eczema herpeticum?

Answer 15

• Itchy, red rash (eczema) has become vesicular and painful

- Systemic symptoms = fever, lethargy, reduced oral intake

Question 16

Describe the management of eczema herpeticum

Answer 16

• Potentially life-threatening emergency

- Admission and IV aciclovir

Question 17

Describe the aetiology and pathophysiology of secondary bacterial infection in eczema

Answer 17

• Staphylococcus aureus

- Breakdown in skin’s protective layer allows an entry point

Question 18

What are the clinical features of secondary bacterial infection in eczema?

Answer 18

Worsening in eczema (increased redness, oozing, crusting of the skin)

Question 19

Describe the management of secondary bacterial infection in eczema

Answer 19

Flucloxacillin (oral or IV, depending on severity)

Question 20

Which organisms cause impetigo?

Answer 20

Staphylococcal or streptococcal infection, e.g. Staphylococcus aureus

Question 21

What are the clinical features of impetigo?

Answer 21

• Lesions are usually on the face, around the nose and mouth
• Initially erythematous macules
• Then form honey-coloured crusts

Question 22

Describe the management of impetigo

Are children allowed to go to school?

Answer 22

• 1st line: topical hydrogen peroxide; 2nd line: topical fusidic acid
• Severe cases may require oral antibiotics, e.g. flucloxacillin
• Highly contagious - children MUST NOT go to nursery or school until the lesions are healed, dry and crusted over

Question 23

Which organisms cause periorbital cellulitis?

Answer 23

Staphylococcal or streptococcal infections, e.g. Staphylococcus aureus

Question 24

What are the clinical features of periorbital cellulitis?

Answer 24

• Fever
• Erythema, tenderness and oedema of the eyelid and skin surrounding the eyelid
• Almost always unilateral

Question 25

Give some risk factors for periorbital cellulitis

Answer 25

- Preceding paranasal sinus infection | - Preceding dental abscess

Question 26

Describe the management of periorbital cellulitis

Answer 26

Immediate IV antibiotics (3rd generation cephalosporin) e.g. ceftriaxone, to prevent posterior spread of infection causing orbital cellulitis

Question 27

Which organism that causes scalded skin syndrome?

Answer 27

Staphylococcus aureus (SSSS - Staphylococcal Scalded Skin Syndrome)

Question 28

Describe the pathophysiology of scalded skin syndrome

Answer 28

Staphylococcus aureus produces a toxin which causes the epidermis to blister and peel

Question 29

What are the clinical features of scalded skin syndrome?

Answer 29

- Fever | - Painful, blistering, peeling skin

Question 30

Describe the management of scalded skin syndrome

Answer 30

- IV flucloxacillin - Analgesia - Fluids

Question 31

What is ringworm? What are the clinical features? How is ringworm classified?

Answer 31

- Fungal infection - Itchy, CIRCULAR, erythematous, scaly rash - Well-demarcated Classified according to location: - Tinea capitis = ringworm of the scalp - Tinea pedis = ringworm of the foot (athlete's foot) - Tinea cruris = ringworm of the groin - Tinea corporis = ringworm on the body

Question 32

Describe the management of ringworm

Answer 32

- Topical imidazole creams (e.g. clotrimazole, miconazole) | - Severe cases: add oral antifungal (e.g. fluconazole)

Question 33

Describe the aetiology and pathophsyiology of scabies

Answer 33

Caused by mites (Sarcoptes scabiei) which burrow under the skin and lay eggs

Question 34

What are the clinical features of scabies

Answer 34

- Incredibly itchy - Small red spots - Classical location: starts between fingerwebs then becomes widespread

Question 35

Describe the management of scabies

Answer 35

Treat the patient and all household members/close contacts with a topical insecticide (5% permethrin cream) Wash everything!!!

Question 36

Describe the aetiology of erythema multiforme

Answer 36

Triggered by infection (most commonly HSV) or certain drugs... Drugs: - Antibiotics, e.g. penicillin - NSAIDs, e.g. ibuprofen - Anticonvulsants, e.g. phenytoin, carbamazepine

Question 37

What are the clinical features of erythema multiforme?

Answer 37

- Widespread itchy, erythematous rash | - 'Bullseye' or 'target' lesions

Question 38

Describe the management of erythema multiforme

Answer 38

- Withdraw offending medication if applicable | - Usually self-resolving

Question 39

Describe the pathophysiology of psoriasis

Answer 39

Autoimmune + environmental trigger

Question 40

What are the clinical features of psoriasis?

Answer 40

- Recurrent episodes of dry, flaky, scaly, erythematous patches over extensor surfaces (knees, elbows) and scalp - Guttate psoriasis is a common presentation in children - often follows a streptococcal or viral sore throat/ear infection

Question 41

Describe the management of psoriasis in children

Answer 41

- Topical corticosteroids | - Vitamin D analogues (e.g. calcipotriol)

Question 42

What are the most common birth marks in children?

Answer 42

- Salmon patch (stork mark) - Infantile haemangioma (strawberry birthmark) - Capillary malformation (port wine stain) - Cafe-au-lait spots - Mongolian blue spots - Congenital melanocytic naevi (normal moles)

Question 43

What are the clinical features of a salmon patch birthmark? Is this type of birthmark common? What is the prognosis?

Answer 43

- Flat pink/red patches on a baby's eyelid, forehead or neck at birth - Very common - occur in around half of all babies - Fade completely in a few months

Question 44

What are the clinical features of infantile haemangioma? Are they more common in boys or girls? What is the prognosis?

Answer 44

- Raised red mark on the skin - More common in girls - Rapidly increase in size up to 6 months, then begin to shrink - usually disappear by 7 years of age

Question 45

What are the clinical features of capillary malformation (port wine stain)? What is the prognosis?

Answer 45

- Flat red/purple mark | - Permanent

Question 46

What are the clinical features of cafe-au-lait spots? Can cafe-au-lait spots be a sign of another condition?

Answer 46

- Flat, light-brown patches | - Neurofibromatosis

Question 47

What are the clinical features of Mongolian blue spots? Which populations are they more common in? What is the prognosis?

Answer 47

- Flat, dark purple/blue marks - Usually appear over the lower back/buttocks - More common in darker-skinned populations - Usually disappear