Dermatology Flashcards
1
Q
What is eczema?
A
An itchy, dry inflammatory skin disease
2
Q
Give examples of endogenous types of eczema.
A
- Atopic – ‘genetic barrier dysfunction’
- Seborrheoic – face/scalp – scale associated
- Discoid – annular/circular patches
- Pomphylx – vesicles affecting palms/soles
- Varicose – oedema/venous insufficiency
3
Q
Give examples of exogenous types of eczema.
A
- Allergic contact dermatitis (sensitised to allergen)
- Irritant contact dermatitis (friction, cold, chemicals e.g. acids, alkalis, detergents, solvents)
- Photosensitive/photoaggravated eczema
4
Q
What can flares of eczema be associated with?
A
- Infections/viral illness
- Environment: central heating, cold air
- Pets: if sensitised/allergic
- Teething
- Stress
- Sometimes no cause for flare found
5
Q
What is the commonest type of eczema?
A
Atopic
6
Q
What is atopy?
A
Overactive immune response to environmental stimulus
7
Q
How can atopy lead to eczema?
A
Immune mediated defects in the skin barrier leads to dry inflamed skin
8
Q
What is the triad of atopy?
A
- Asthma
- Eczema
- Hayfever
Can have 1, 2 or 3 and usually FMH
9
Q
How does atopic eczema tend to present in infancy?
A
Typically starts on the face/neck (cheeks common), can spread more generally
10
Q
How does atopic eczema present in older children?
A
- Flexural pattern predominates (antecubital fossae, popliteal fossae, wrists, hands, ankles).
- Facial eczema also possible/can recur.
11
Q
What causes atopic eczema?
A
- Inherited abnormalities in the skin leading to barrier defect
- Abnormality in filaggrin expression
12
Q
What does filaggrin do?
A
- Filaggrin proteins bind the keratin filaments together.
- Also play a role in producing a natural moisturising factor.
13
Q
What is the consequence of losing skin barrier function?
A
Loss of water
- Irritants may penetrate (soap, detergent, solvents, dirt)
- Allergens may penetrate (pollens, dust-mite antigens, microbes)
14
Q
Who is usually affected by seborrheoic dermatitis?
A
Often babies under 3 months, usually resolves by 12 months
15
Q
What is seborrheoic dermatitis associated with in infants?
A
Cradle cap
16
Q
Where does seborrheoic dermatitis mainly affect?
A
Scalp and face
17
Q
What microorganism is sebeorrhoeic dermatitis associated with?
A
Associated with proliferation of various species of the skin commensal Malassezia in its yeast form.
18
Q
How is seborrheoic dermatitis treated?
A
- Emollients
- Antifungal creams
- Antifungal shampoos
- Mild topical steroids
19
Q
How does discoid eczema present?
A
Scattered annular/circular patches itchy eczema
20
Q
How can discoid eczema occur?
A
As part of atopic eczema or as a separate entitiy
21
Q
Where does pomphylx eczema affect?
A
Hand and foot
22
Q
How does pomphylx eczema present?
A
- Characterised by vesicles on the hand and feet
- Intensely itchy
23
Q
Where does varicose eczema affect?
A
Affects legs in association with venous insufficicency
24
Q
What is varicose eczema often associated with?
A
- Oedema
- Varicose veins
- Chronic leg swelling
25
How does varicose eczema present?
- Skin dry and inflammed
| - Skin may ulcerate
26
How is varicose eczema treated?
- Emollients
- Topical steroids
- Compression stockings
27
What causes allergic eczema?
Becoming sensitised to an allergen
28
What type of testing may be useful in allergic eczema?
Patch testing
29
What causes irritant eczema?
Repeated contact
- Water and soaps
- Touching irritant foods such as citrus and tomatoes
- Chemical irritants
30
Should children with eczema have allergy testing?
- Eczema has many causes and allergy is just one
- Majority of children with mild eczema do not need allergy testing
- 80% of childhood eczema is mild
31
When should food allergy be suspected?
- Immediate reactions (lip swelling, facial redness/itching, anaphylactoid symptoms)
- Late reactions (worsening of eczema 24/48 hours after ingestion) – especially if pattern with specific food (food diaries encouraged).
- GI problems
- Failure to thrive
- Severe unresponsive eczema
- Severe generalised itching
32
How can food allergy be tested for?
- Blood test for specific IgE antibodies to certain foods
| - Skin prick testing
33
What are the commonest food allergies?
- Milk/dairy
- Soy
- Peanuts
- Eggs
- Wheat
- Fish
34
What should you beware of in allergy testing?
False positive tests and limitations of allergy testing particularly in atopic eczema
35
Give examples of airborne allergens.
- House dust mite
- Pet dander
- Pollen
36
How should food allergies be confirmed?
- Dietary restrictions/eliminations >8 weeks – refer dietitian
- Eliminate one food at a time
- Reintroduce food to confirm allergy
37
How should eczema be treated?
- Emollients (Lotions, creams or ointments – fragrance free, greasier ointments more effective)
- Topical steroids
- Calcineurin inhibitors (e.g protopic – steroid sparing topical agents)
- UVB light therapy
- Immunosuppressive medication
38
What is a possible side effect of topical steroids?
Skin thinning with prolonged use
39
Give examples of different strengths of topical steroids.
- Very potent (Dermovate)600x
- Potent (Betnovate)100x
- Moderate (Eumovate) 25x
- Mild (Hydrocortisone)
40
How much steroid should be applied?
1 finger tip unit covers the area of a palm
41
How should steroids be used?
- Once daily for 1-2 weeks
- If improvement then use alternate days for a few more days
- Then if stubborn/persistent areas can use twice weekly in these areas
- If at any point the eczema starts flaring, go back to daily applications
42
What is impetigo?
A common acute superficial bacteria
43
How does impetigo present?
Pustules and honey-coloured crust erosions
44
What is the causative agent of impetigo?
Staph aureus
45
How is impetigo treated?
- Topical antibacterial (fucidin)
| - Oral antibiotic (flucloxacillin)
46
What is molluscum contagiosum?
Common benign self-limiting infection
47
What is the causative organism in molluscum contagiosum?
Moluscipox virus
48
How is molluscum contagiosum transmitted?
Transmission to close direct contacts
49
How does molluscum contagiosum present?
Pearly papules with umbilicated centres
50
What is the incubation for molluscum contagiosum?
2 weeks - 6 months
51
How is molluscum contagiosum managed?
- Can take up to 24 months to clear
- Reassurance
- 5% potassium hydroxide
52
What are viral warts?
Common non-cancerous growths of the skin caused by infection with HPV
53
What are warts on the sole of the foot known as?
Verucas
54
How do viral warts present?
Often skin coloured growths
55
How are viral warts transmitted?
Direct skin contact
56
How are viral warts treated?
- Need to stimulate own immune system to respond
- Cryotherapy
- Topical paints (salicylic acid)
- 90% will resolve in 24 months
57
What is viral exanthems associated with?
Viral illness
- Chicken pox
- Measles
- Rubella
- Roseola (herpes virus 6)
- Erythema infectiosum (parvovirus B19, slapped cheek)
58
Why does viral exanthems occur?
Either reaction to a toxin produced by the organism, damage to the skin by the organism or an immune response
59
How does viral exanthems present?
- Fever
- Malaise
- Headache
60
What is chickenpox?
- Chickenpox is a highly contagious disease caused by primary infection with the varicella-zoster virus.
- One infection is thought to confer lifelong immunity.
61
Who is susceptible to the varicella zoster virus at all times?
Immunocompromised individuals
62
How does chickenpox present?
- Red papules (small bumps) progressing to vesicles (blisters) often start on the trunk.
- Itchy. Associated with viral symptoms.
63
What is the timeline of chickenpox?
- Incubation 10-21 days
- Contagious 1-2 days before rash appears and until lesions have crusted
- Self limiting
64
What are some rare complications of chickenpox?
- Pneumonia
| - Encephalits
65
How is chickenpox treated?
- Self-limiting
| - Infection control (keep of school/nursery)
66
What are some other names for slapped cheek?
- Fifth disease
| - Erythema infectiosum
67
What causes slapped check?
Parovirus
68
How does slapped check present?
- Viral symptoms.
| - Erythematous rash cheeks initially and then also lace like network rash (trunk and limbs). Can take 6w to full fade.
69
What does parovirus target?
Red cells in bone marrow
70
How does slapped check resolve?
Mild self-limiting illness
71
What is in the incubation period for slapped check?
7-10 days
72
What are some rare complications of slapped check?
- Aplastic crisis (if haemolytic disorders)
| - Risk to pregnant women (spontaneous abortion, intrauterine death, hydrops fetalis)
73
What causes hand foot and mouth disease?
Enterovirus
- Coxsackie virus A16
- Enterovirus 71
- Other Cxsackie virus
74
How does hand foot and mouth disease present?
- Blisters on the hands, feet and in the mouth
| - Viral symptoms
75
When do epidemics of hand foot and mouth disease occur?
Late Summer or Autumn months
76
How is hand foot and mouth disease managed?
- Self-limiting
| - Treatment is supportive
77
How does orofacial granulomatosis present?
- Lip swelling and fissuring
| - Oral mucosal lesions: ulcers and tags, cobblestone appearance
78
What is orofacial granulomatosis associated with?
Crohn's disease
79
What are the clinical features of erythema nodosum?
- Painful, erythematous subcutaneous nodules
- Over Shins; sometimes other sites
- Slow resolution - like bruise,6-8 weeks
80
What are the causes of erythema nodosum?
- Infections: Streptococcus, Upper respiratory tract
- Inflammatory bowel disease
- Sarcoidosis
- Drugs: OCP, Sulphonamides, Penicillin
- Mycobacterial Infections
- Idiopathic
81
What is dermatitis herpetiformis?
Rare but persistent immunobullous disease that has been linked to coeliac disease
82
How does dermatitis herpetiformis present?
- Itchy blisters can appear in clusters
- Often symmetry
- Scalp, shoulders, buttocks, elbows and knees
83
How is dermatitis herpetiformis investigated?
- Detailed history
- Coeliac screening
- Skin biopsy
84
How is dermatitis herpetiformis treated?
- Emollients
- Gluten free diet
- Topical steroids
- Dapsone
85
What are the classes of urticarial?
- Acute <6 weeks
| - Chronic >6 weeks
86
What can cause urticarial?
- Viral infection
- Bacterial infection
- Food or drug allergy
- NSAIDS, OPIATES,
- Vaccinations
87
What is usually the cause of chronic urticaria?
- Idiopathic
| - Can be autoimmune
88
How does urticarial present?
- Wheals/hives
- Associated angioedema (10%)
- Areas of rash can last from few minutes up to 24 hours
89
What is the treatment for urticarial?
-Withdraw possible triggers
Antihistamines
- Newer generation (desloratadine)
- 3 x daily
-Ranitidine
Montelukast
-Omalizumab
-Ciclosporin
