Derm Flashcards
1
Q
What is Impetigo?
A
- superficial bacterial skin infection usually caused by either Staphylcoccus aureus or Streptococcus pyogenes
- can be primary infection or complication of an existing skin condition such as eczema, scabies or insect bites
2
Q
Who is most likely to get Impetigo?
Where does it typically occur?
A
- More common in children
- Particularly during warmer weather
- Tend to occur on the face, flexures and limbs no covered by clothing
3
Q
How is Impetigo spread?
A
- Direct contact with discharge from the scabs of infected person
- Bacteria enter skin through minor abrasions
- Infection is spread mainly by hands but can spread via toys, clothing, equipment and the environment may occur
4
Q
Incubation period for Impetigo?
A
- Golden crusted lesions, typically found around the mouth
- Very contagious
4-10 days
5
Q
Management of limited, localised disease - impetigo?
A
- 1st line: Hydrogen peroxide 1% creams- for people who are not systemically unwell or at high risk of complication
- Topical abx creams: Topical fusidic acid, topical mupirocin should be used if fusidic acid resistance is suspected
6
Q
Management of extensive Impetigo?
A
- Oral flucloxacillin
- Oral erythromycin if penicillin allergic
7
Q
Do children who have Impetigo need to be excluded from school?
A
- Children should be excluded from school until lesions are crusted and healed
- OR 48 hours after commencing abx treatment
8
Q
What is infantile acne?
A
- < 3months of life,
- Transient
- Usually due to maternal androgens
9
Q
What is the pathophysiology of adolescent acne?
A
- Increased sebum production: androgenic stimulation of hyper-responsive pilosebaceous units
- Impaired flow of sebum: Obstruction of the pilosebaceous duct by hyperkeratosis
- Propionobacterium acnes: gram postive anaerobe is implicated in the inflammation
10
Q
Risk factors for adolescent acne?
A
- Puberty
- May increase pre-menstrually
- POS
- Excess cortisol
11
Q
Presentation of acne?
A
- Greasy skin- may be painful
- Open comedones: whiteheads
- Closed comedones: blackheads
- Other features: pustules, nodules, cysts, scarring, seborrhoea
12
Q
Investigations for Acne?
A
- Usually clinical diagnosis, unless other signs of andorgen excess e.g. pre-pubertal body odour, axillary/pubic hair or genital maturation; postpubertal infrequent menses, hirsuitism, or truncal obesity
- If androgen excess suspected: Bloods (free testosterone), FSH, LH
- Urine: 24 hour urinary cortisol (if suspect Cushings)
13
Q
General Mangement for Acne?
A
- Non-greasy cosmetics
- Daily face wash
14
Q
Complications of Acne treatment?
A
- Facial scarring
- Hyperpigmentatio
- Secondary infection
- Fistulas
- Psychosocial: Lack of self-confidence
15
Q
What are abx available for acne management?
A
16
Q
What are topical preparations available for acne management?
A
17
Q
What is atopic Eczema?
A
- Chronic inflammatory itchy skin condition
- Same as atopic dermatitis: except atopic dermatitis has more clear trigger
18
Q
Environmental factors that can trigger atopic ezcema?
A
- Irritants
- Infections
- Contact with food or inhalant allergens
19
Q
Presentation of Atopic Ezcema?
A
- Majority begins first year of life
- Intense itchy skin
- Chronic relapsing inflammation of skin are cardinal features
- Infantile: affects face and extensor surfaces and spares the nappy area
- Older children: Flexural involvement more common
*
20
Q
Presentation of ezcema herpeticum rash?
A
- Widespread, painful, vesicular rash- vesicles filled with pus: when they burst they leave:
- Small uniform circular ‘punched out erosions’
21
Q
Investigations of ezcema
A
- Usually clinical
- Infants w moderate- severe ezcema w history of immediate reaction to food: Need skin prick testing to common food allergens
22
Q
What is Ezcema Herpeticum?
A
- Viral skin infection caused by herpes simplex virus or varicella zoster virus
- Usually occurs in a pt with pre-existing skin condition e.g. atopic ezcema or dermatitis
23
Q
Symptoms of Ezcema Herpeticum?
A
- Rash: widespread- erythematous, painful with pus filled vesicles
- Systemic symptoms: fever, lethargy, irritability and reduced oral intake
- Lymphadenopathy
24
Q
Investigations for Ezcema Herpeticum?
A
- Can do viral swabs to confirm the diagnosis
- Usually not needed: clinical diagnosis
25
Management of Ezcema Herpeticum?
* Aciclovir
* Mild or moderate: oral
* Severe: IV
26
Complications of ezcema herpeticum?
* Can lead to life-threatening infection: esp if immunocomprised
* Bacterial superinfection can occur - this will need abx
27
Managment of atopic ezcema?
* Assess eczema severity and quality of life, incl everyday activities and sleep, and psychosocial well-being. Identify and manage any trigger factors. Give advice on prompt recognition and treatment of infection (in particular eczema herpeticum) and provide a written eczema management plan.
* Emollients: ‘ Total emollient care ’ includes liberal application of creams and ointments, using a soap substitute and bath oil.
* Topical corticosteroids: Use a stepwise approach to topical steroids depending on the severity of eczema. Use mild steroids for the face. In children with recurrent flares, use a topical steroid for 2 consecutive days/week.
* Topical calcineurin inhibitors: Can be used as second-line treatment of moderate to severe atopic eczema in children 2 years that is not controlled by topical corticosteroids, or where there are adverse effects to topical steroids.
* Wet wraps: May be particularly effective for troublesome areas (feet/hands). Not to be used over infected skin, topical potent steroids or calcineurin inhibitors.
* Dietary manipulation: In bottle-fed infants 6 months with moderate to severe eczema not controlled by optimal treatment, 6 – 8-week trial of an extensively hydrolysed or amino acid formula in place of cow ’ s milk formula.
* Antihistamine: If children suffer from severe itching, trial a non-sedating antihistamine.
28
Complications of Ezcema?
* Skin infections leading to cellulitis
* Residual pigmentations
* Lichenification or skin atrophy related to long- term potent steroid use
* Psychosocial issues
29
What are the 2 main types of contact dermatitis?
* Irritant
* Allergic
30
What is irritant contact dermatitis?
* more common
* non- allergic reaction due to weak acids or alkalis
* Often seen on hands
* Erythema is TYPICAL
* Crusting and vesicles are RARE
31
What is allergic contact dermatitis?
* Type IV hypersensitivity reaction
* Uncommon
* Most common: hair following hair dyes
* Presents as acute, weeping ezcema- affecting margins of hairline rather than hairy scalp
* Topical treatment with potent steroid is indicated
32
What is Psoriasis?
Chronic autoimmune condition that causes symptoms of psoriatic skin lesions
33
Describe psoriatic skin lesions
* Dry, flaky, scaly, faintly erythematous skin lesions
* Appear raised and rough plaques
* Commonly over extensor surfaces of the elbows and knees and on the scalp
34
What is the pathophysiology of psoriatic plaques?
* Rapid generation of new skin cells, resulting in an abnormal build up and thickening of the skin in those areas
35
What is plaque psoriasis?
* Most common form in adults
* Thickened erythematous plaques with silver scales
* commonly seen on extensor surfaces and scalp
36
What is guttate psoriasis?
* commonly occurs in children
* small raised papules across trunk and limbs
* Papules are mildly erythematous and can be lightly scaly
* Over time the papules can turn into plaques
* Often triggered by a strep throat infection, stress or medications
* Often resolves spontaneously within 3-4 months
37
What is pustular psoriasis?
* rare and severe form
* pustules form underneath areas of erythematous skin
* Pts can be systemically unwell
* Treated as medical emergency
* Need hosp admission
38
What is Erythrodermic Psoriasis?
* rare, severe form of psoriasis
* extensive erythematous inflamed areas covering most of the surface are of the skin
* Skin comes away in large patches- exfoliation and results in many exposed areas
* Medical emergency- pts need admission
39
Child has a throat infection, 2 weeks later they develop small raised papules across they trunk and limbs. What is this?
* Guttate psoriasis
40
How do psoriatic plaques differ in children compared to adults?
Plaques are
* smaller
* softer
* less prominent
41
What are the specific signs for psoriasis?
* Auspitz sign- small points of bleeding when the plaques are scraped off
* Koebner phenomenon- refers to development of psoriatic lesions to areas of skin affected by trauma
* Residual pigmentation- of the skin after lesions resolved
42
Diagnosis of psoriasis?
* Clinical, based on appearance of lesions
43
Managment of psoriasis in children?
* In children ususally managed and followed up by a specialist
Treatment options:
* Topical steroids
* Topical vitamin D analogues (calcipotriol)
* Topical dithranol
* Phototherapy with narrow band ultraviolet B light is particularly useful in extensive guttate psoriasis
If treatment fails children may be trialled on unlicensed systemic treatment e.g. methotrexate, retinoids
| Topical calcineurin inhibitors (tacrolimus) are usually only used in adu
44
Associations with psoriasis?
* Nail psoriasis- can occur at any age: changes incl pitting, thickening, discolouration, ridging and onycholysis
* Psoriatic arthritis- occurs within 10 years of developing skin changes- usually affects middle age but can occur at any age
* Psychosocial
45
What is a cutaneous common wart?
* firm, raised papules with a rough surface that resembles a cauliflower
* Usually asympotmatic but may be tender
46
How do you diagnose cutaneous common warts?
* Usually clinical
* If doubt, light paring of the wart will reveal a tiny black dots on the surface (thrombosed capillaries)
47
Managment of cutaneous warts?
* Most people not a strong care for treating warts
* Do not usually cause symptoms and in most cases will resolve within months or at most 2 years
* Treatments incl:
* Cyrotherapy
* Topical salicylic acid
* Curettage and cautery
48
Adverse affects of cryotherapy for cutaneous common warts?
* Several treatments
* Can be painful
* May cause pain, blistering, infection, scarring and depigmentation
49
Adverse effects of topical salicylic acid for cutaneous common warts?
* May require administration for up to 12 weeks
* Can cause local skin irritation
50
When should you consider treatment for cutaneous common warts?
* Wart is painful
* Wart is cosmetically unsightly
* Person requests treatment, and the wart is persisiting
* Immunosupressed patient
51
What is a viral wart?
* Benign lesion caused by HPV infection
* Can be classified as cutaneous or mucosal
* Cutaneous wart are your common warts, verrucas
52
Who gets cutaneous warts?
* School- aged kids
* Dermatitis
* Drug induced immunosupression
* HIV patients
53
What type of virus is HPV?
* Double stranded DNA
54
How does HPV cause cutaneous warts?
* Infection begins in basal layer of epidermis
* This causes proliferation of keratinocytes and hyperkeratosis and production of infectious viral particles- the wart
55
Most common HPV types affecting the skin?
* 1,2,3,4,10,27,29 and 57
56
How are cutaneous warts spread?
* direct skin-skin contact
* autoinoculation
57
What is a cutaneous plantar wart?
* Two types:
* Myrmecial type: Caused by HPV 1: typically tender
* Mosaic warts: caused by HPV 2
58
What is a cutaneous plane wart?
* Typically multiple flat topped skin coloured papules located most commonly on face, hands and shins
* Caused by HPV type 3 and 10
