10- Paediatric Dermatology 2/2 Flashcards
There are a few specific signs suggestive of psoriasis:
- Auspitz sign refers to small points of bleeding when plaques are scraped off
- Koebner phenomenon refers to the development of psoriatic lesions to areas of skin affected by trauma
- Residual pigmentation of the skin after the lesions resolve
acne vulgaris background
- Very common condition
- Acne – comedowns
- Open comedowns- blackheads
- Closed comedowns- whiteheads
Pathophysiology of acne vulgaris
- Caused by chronic inflammation, with or without localised infection, in pockets of skin known as pilosebaceous unit
- Acne results from increased production of sebum, trapping keratin and blocking the pilosebaceous unit
- Leads to swelling and inflammation
- Androgenic hormones increase production of sebum- therefore exacerbated by puberty and improves with anti-androgenic hormonal contraception
- Bacteria: Propionibacterium acnes – bacteria which colonises the skin and can contribute to acne
RF for acne
- Puberty and adolescence
- Family history
Presentation of acne
- Significant variation in every of acne
- Red, inflamed and sore spots on the skin
- Typically distributed
o Face
o Upper chest
o Upper back
Management of acne
Stepwise
- No treatment if mild
- Psychosocial counselling
- Topical benzoyl peroxide
- Topical retinoids (chemicals related to vitamin A)- slows production of sebum
- Topical antibiotics – clindamycin (prescribed with benzoyl peroxide to reduce bacterial resistance)
- Oral antibiotics such as lymecycline (make sure not pregnant- tetracycline is a teratogen)
- Oral contraceptive pill e.g. Co-cyprindiol (Dianette)- COCP
- Oral retinoids e.g. isotretinoin
Oral retinoids
Isotretinoin i.e. Roaccutane
- Effective last line option
- Prescribed by specialist
- Highly teratogenic
- Women must have reliable contraception and do regular pregnancy tests
o And agree to termination if gets pregnant
o Stop a month before trying to get pregnant
MOA of roaccutane
- Reduce production of sebum, reducing inflammation and bacterial growth
side effects of oral retinoids
- Dry skin and lips
- Photosensitivity of the skin to sunlight
- Depression, anxiety, aggression and suicidal ideation. Patients should be screened for mental health issues prior to starting treatment.
- Rarely Stevens-Johnson syndrome and toxic epidermal necrolysis
Describing lesions: Acne
- Pustules are small lumps containing yellow pus
- Comedomes are skin coloured papules representing blocked pilosebaceous units
- Blackheads are open comedones with black pigmentation in the centre
- Ice pick scars are small indentations in the skin that remain after acne lesions heal
- Hypertrophic scars are small lumps in the skin that remain after acne lesions heal
- Rolling scars are irregular wave-like irregularities of the skin that remain after acne lesions heal
impetigo background
Very contagious superficial bacterial infection
Classified as
- Non-bullous
- Bullous
–> Epidermolytic toxins released by S.aureus break down proteins that hold skin cells together
–>This causes fluid filled vesicles
impetigo pathophysiology
Causative organism
- Usually Staphylococcus aureus
- Streptococcus pyogenes
Occurs when bacteria enter via a break in the skin
- Can be otherwise healthy skin
- Or related to eczema or dermatitis
presentation of impetigo
- Golden crust
1) Non-bullous impetigo
- Around nose or mouth
- ‘golden crust’
- Unsightly
- No systemic symptoms of illness
2) Bullous
- More common in neonates and children <2
- Always causes by staphylococcus aureus
- Fluid filled vesicles which grow in size and bursh, forming a “golden crust:
- Heal without scaring
- Can be painful and itchy
- Systemic symptoms
- Severe infection called : staphylococcus scalded skin syndrome
RF for impetigo
- Age. Impetigo occurs most commonly in children ages 2 to 5.
- Close contact. Impetigo spreads easily within families, in crowded settings, such as schools and child care facilities, and from participating in sports that involve skin-to-skin contact.
- Warm, humid weather. Impetigo infections are more common in warm, humid weather.
- Broken skin. The bacteria that cause impetigo often enter the skin through a small cut, insect bite or rash.
- Other health conditions. Children with other skin conditions, such as atopic dermatitis (eczema), are more likely to develop impetigo. Older adults, people with diabetes or people with a weakened immune system are also more likely to get it.
Stopping the spread: impetigo
Impetigo is very contagious so children should be kept off school during infection
- Until lesions have healws or had antibiotics for >48 hours
Advice for patient
- to not scratch or touch lesions
- hand hygiene
- avoid sharing face towels and cutlery
contact dermatitis backgroun
- Itchy rash caused by direct contact with allergen
- Delayed Type 4 hypersensitivity reaction
- Types
o Chemical burns
o Irritant contact dermatitis
o Allergic contact dermatitis
pathophysiology of contact dermatitis
Common in children because skin is easily sensitised:
- Thinner skin than adults
- Can absorb more applied substances
- More likely to have underlying atopic dermatitis which facilitates sensitisation due to impaired skin barrier
- Sensitization can occur in newborns from ages 0-3, prevalence of subsequent allergic contact dermatitis increases with age
causes of contact dermatitis
- Nickel (piercings, buttons, fasteners, clips, toys)
- Fragranced products
- Colophonium found in plasters
presentation of contact dermatitis
- Shows up on skin after direct contact e.g. face, hands, feet, arms, legs
- When allergen is removed, rash slowly resolves over several days to several weeks and will reappear with further contact
- Always itchy
- Erythematous blisters
- Oedema
- Dryness
- Fissuring
- Lichenification
- Pigmentation increase or decrease
investigations for contact dermatitis
patch testing
management of contact dermatitis
- Once cause has been identified, avoid direct contact (lifelong)
- Avoid soap and dry skin carefully after washing
- Short course of topical corticosteroid cream
o Hydrocortisone for face - Emollients frequently applies
- Severe: oral corticosteroids e.g. prednisone
- Second line: calcineurin inhibitor
Warts/ human papilloma virus
- Common benign lesion caused by infection with human papilloma virus
- Can be classified by site as being:
o Cutaneous e.g. Verrucas
o Mucosal e.g. Sexually acquired anogenital warts
Pathophysiology of warts/HPV
HPV
- Double stranded DNA virus
- Infection begins in the basal layer of the epidermis, causing proliferation of the keratinocytes (skin cells) and hyperkeratosis, and production of infectious virus particles- the wart
- Virus subtypes which infect the skin: 1,2,3,4,10,27,29,57
- Spread via direct skin to skin contact or autoinoculation
e.g. if a wart is scratched or picked may devlop under the fingernail
- Incubation period as long twelve months
RF for warts/ HPV
- School aged children
- People with immunosuppression
presentation of warts/ HPV
- Cutaneous viral wards are hard due to their keratinous surface
- Tiny red or black dots can be visible in the wart are papillary capillaries
management of Warts/ human papilloma virus
Most warts resolve spontaneously especially in children
Indication for active treatment
- Immunosuppression
- Presence of complications
- Patient preference
treatmeants for warts
Topical treatment
- Paints or patches containing salicylic acid or podophyllin which remove the surface skin cells
- Applied once daily
Cryotherapy
- Liquid nitrogen – 3-4 months of regular freezing
Electrosurgery
- Curettage and cautery for large and resistant warts
Others
- Imiquimod cream
- Bleomycin injections
prevention of warts
o Wash hands regularly don’t touch warts
o Vaccines for anogenital warts
HPV vaccines
Girls and boys aged 12 to 13 years (born after 1 September 2006) are offered the human papillomavirus (HPV) vaccine as part of the NHS vaccination programme.
The HPV vaccine helps protect against cancers caused by HPV, including:
- cervical cancer
- some mouth and throat (head and neck) cancers
- some cancers of the anal and genital areas
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It also helps protect against genital warts.
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gardasil 9
Gardasil 9 protects against 9 types of HPV: 6, 11, 16, 18, 31, 33, 45, 52 and 58.
Cervical cancers: types 16 and 18 are the cause of most cervical cancers in the UK (more than 80%).
- These types of HPV also cause most anal cancers, and some genital and head and neck cancers.
Genital warts: types 6 and 11 cause around 90% of genital warts, so using Gardasil 9 helps protect girls and boys against both cancer and genital warts.
