Inflammatory skin diseases Flashcards
1
Q
What is the epidermis mainly composed of?
A
Epithelial cells
Melanocytes
2
Q
What do epithelial cells do
A
They make keratin to make keratocytes
3
Q
List the board categories non infectious inflammatory diseases can fall under
A
- Dermatitis/ psoriasis
2, Blistering - Connective tissue damage
- Skin lesions as a sign of systemic disease
- Skin lesions caused by metabolic disorders
4
Q
Name the most common disease of the skin
A
Eczema/ dermatitis
5
Q
What does eczema describe
A
A reaction pattern rather than a specific disease
6
Q
How common is eczema in children
A
5% of children in the UK have eczema
7
Q
What is another name for eczema?
A
Dermatitis
8
Q
Name the stages of dermatitis
A
- Acute dermatitis
- Subacute dermatitis
- Chronic dermatitis
9
Q
Describe the acute stage of dermatitis
A
Red skin
Weeping serous exudate
There may be some small vesicles
10
Q
Describe the subacute phase of dermatitis
A
Skin is red and crusty
Less exudate
Very very itchy skin
11
Q
Describe the chronic stage of dermatitis
A
Skin is thick and leathery
12
Q
How does eczema look under a microscope during the acute phase?
A
You’ll see oedemas within the epidermis and fluid filled blisters (spongiosis)
13
Q
How does eczema look under a microscope during the chronic stage
A
Epidermis has become thickened and and the normal undulations of the epidermis became quite pronounced
spongiosis is much less
Keratin layer is bigger and thicker
14
Q
What is spongiosis
A
Intercellular oedema within the epidermis
15
Q
Name the different types of of eczema
A
- Atopic eczema
- Contact irritant dermatitis
- Contact allergic dermatitis
- Dermatitis of unknown aetiology
16
Q
Who usually has atopic eczema
A
Children with family history
Often associated with asthma and hay fever
17
Q
What type of inflammatory disease is atopic eczema
A
A type 1 hypersensitivity reaction to an allergen
18
Q
What is contact irritant dermatitis caused by
A
Direct injury to skin by irritant eg acid, alkali, strong detergent
19
Q
What is contact allergic dermatitis caused by
A
Nickel, dyes, rubber
These act as happens which combine with epidermal protein to become immunogenic
20
Q
What type of inflammatory disease is contact allergic dermatitis?
A
A delayed type 4 hypersensitivity reaction
21
Q
What are dermatitis with an unknown aetiology categorised by?
A
Their morphological subtypes
22
Q
List the 2 morphological subtypes dermatitis of unknown aetiology can fall under
A
- Seborrhoeic dermatitis
2. Nummular dermatitis
23
Q
Describe seborrhoeic dermatitis
A
Dermatitis that affects areas rich in sebaceous glands
EG scalp, forehead, upper chest
24
Q
Describe nummular dermatitis
A
Coin shaped lesions
25
How common is psoriasis
Affects 1-2% of population
26
Describe how psoriasis looks
1. Well defined, red oval plaques on extensor surfaces (knees, elbows, sacrum)
2. Fine silvery scale
27
What happens if you pick at a scale caused by psoriasis (what is this called)
Removal of scale causes small bleeding portitis
| This is called Auspitz sign
28
List some associating symptoms that people may psoriasis may present with
1. Pitting nails
| 2. Sero negative arthritis
29
Describe the appearance of psoriasis under a microscope
1. Regular e longed club shaped rete ridges
2. Thickening of epidermis over dermal papillae
3. Parakeratotic (contains nuclei) scaled
4. Collections of neutrophils in scale
30
What does parakeratoic mean
Contains nuclei
31
What is the appearance of psoriasis under a microscope called?
Psoriasiform hyperplasia
32
What do the clinical and microscopic features of psoriasis suggest?
They reflect massive cell turnover
33
Describe the pathogenesis of psoriasis
Trigger factor leading to a dysfunctional immune reaction
34
Talk through the aetiology of psoriasis
1. Genetic factors
| 2. Environmental trigger factors such as infection, stress, trauma and drugs
35
Which gene may be responsible for genetic psoriasis
Theres multiple loci on the psoriasis susceptibility or PSORS genes
Many of these loci lie in the region of major histocompatibility complex on chromosome 6p2
36
Name some diseases that are associated with psoriasis
1. Arthropathy (5-10% associated)
2. Psychosocial effects
3. Cardiovascular disease
4. Cancer increased risk of non melanoma skin cancer
37
What is the most common treatment plan for psoriasis and what problems can this cease?
UV light is the main treatment option
| This is a risk factor for developing skin cancer
38
How can psoriasis manifest in the oral cavity?
1. Geographical tongue
| 2. Angry red patches on the hard palette
39
What is lupus erythematosus
It is an auto immune disorder primarily affecting connective tissues of the body
40
Which organ is mainly affected by lupus erythematosus
Can affect any part of the body but most importantly kidneys
41
What happens in lupus erythematosus
Autoantibodies are directed at various tissues
42
Which parts of the body are affected by systemic lupus erythematosus
Can affect all parts of the body eg:
1. Brain
2. Skin
3. Renal system
4. Can cause fever
43
Name the types of lupus erythematosus that affect the skin
1. Discoid lupus erythematosus
| 2. Systemic lupus erythematosus
44
Describe the clinical presentation of discoid lupus erythematosus
Affects only the skin
| Leads to red scaly patches on sun exposed skin, can cause scarring
45
what does scalp involvement in discoid lupus erythematosus cause
Alpoecia
46
Describe the clinical presentation of systemic lupus erythematosus
It is a visceral disease that MAY involve the skin
| Butterfly rashes on cheeks and nose
47
Describe how lupus erythematosus looks under a microscope
Thin atrophic epidermis, inflammation and destruction of adnexal structures
IgG deposited in basement membrane
48
How do we confirm a diagnosis of lupus erythematosus
1. We create an antibody to the endogenous lupus antibodies
2. Attach a fluorescent signal to the antibody
3. Mix a sample of skin and the antibody
4. if under a microscope you seen fluorescence then you have lupus erythematosus antigens in the sample
49
Name a condition that can give an almost identical histological presentation to lupus erythematosus
Dermatomyositis
50
What is Dermatomyositis
Peri ocular oedema and erythema (heliotropic rash)
51
What can Dermatomyositis cause
1. Erythema in photosensitive distribution
| 2. Myositis: proximal muscle weakness
52
What is Dermatomyositis associated with in adults
In adults 25% of Dermatomyositis cases are associated with underlying visceral cancer
53
What is Dermatomyositis characterised by?
heliotropic rash
54
Describe the microscopy of Dermatomyositis
Very similar to lupus : 1. Thin atrophic epidermis, inflammation and destruction of adnexal structures
2. IgG deposited in basement membrane
Often there's a lot of dermal mucin
Negative Immuno fluorescent test
55
Describe the presentation of lichen planus
Appears on the flexor surfaces, mucous membranes and genitals of adults
Can last for 1-2 years or longer in the oral cavity
56
What is lichen planus
A type 4 hypersensitivity reaction
57
What is lichen planus associated with
Viral hepatitis. HIV and drug use
58
How do bullous diseases manifest
Manifest as the formation of fluid filled blisters
59
Name the 2 types of bullous skin diseases
1. Pemphigus
| 2, Pemphigoid
60
What is the difference in Pemphigus and Pemphigoid manifestation
Where the fluid filled blisters form in the epidermis
61
Where do blisters form in Pemphigus
Blisters form within the epidermis (intra epidermal bulla)
62
Where do blisters form in pemphigoid
Blisters form at the bottom of the epidermis (sub epidermal bulla)
63
Describe pemphigus blisters
Quite fragile and can easily fall off
64
Describe pemphigoid blisters
Quite tense and robust
65
What type of diseases are bullous diseases
They are autoimmune diseases
66
Where do antibodies form in pemphigus?
Form in intercellular junctions
67
Where do antibodies form in pemphigoid?
In the basement membrane
68
What is pemphigus
It's a group of disorders characterised by loss of cohesion between keratinocytes resulting in an intraepidermal blister
69
What do all types of pemphigus cause
Cause fragile blisters/ bullae which rupture easily
| Can be extensive and may involve the mucous membrane
70
Describe the pathogenesis of pemphigus
Autoantibodies are directed against intercellular materials
71
How can pemphigus be detected
By imminofluoresecence (IMF)
72
What is bullous pemphigoid
A disease characterised by subepidermal blisters
| These blisters are large and tense and down rupture easily
73
Describe the pathogenesis of bullous pemphigoid
Autoantibodies to glycoprotein in basement membrane that can be detected by IMF
74
What is dermatitis herpetiformis
Small intensely itchy blisters associated with the deposition of IgA
75
Who is dermatitis herpetiformis most common in
Young people
76
What is dermatitis herpetiformis associated with
Coeliac disease
77
Describe the histopathology of dermatitis herpetiformis
Neutrophil micro-abscesses in dermal papillae
78
Where do blisters caused by dermatitis herpetiformis form
They form sub epidermally and cause IgA in dermal papillae
79
Why is it hard to get a biopsy of a blister caused by dermatitis herpetiformis ?
As they are incredibly itchy and people often scratch away at them before they can be inspected
80
List some skin lesions that are a sign of systemic disease
1. Dermatomyositis
2. dermatitis herpetiformis
3. Ancanthosis nigricans
4. Necrobiosis lipoidica
5. Erythema nodosum
81
What can Dermatomyositis a sign of
Can be a sign of visceral cancer
82
What can dermatitis herpetiformis be a sign of?
Coeliac disease
83
Describe ancanthosis nigricans
Dark warty lesions in the armpits
84
What does IMF stand for
imminofluoresecence
85
What can ancanthosis nigricans be a sign of
Intermal malignancy
86
Describe Necrobiosis lipoidica
Red and yellow plaque on legs
87
What can Necrobiosis lipoidica be a sign of
Diabetes melitus
88
Describe Erythema nodosum
Red tender nodules on the shins
89
What can Erythema nodosum be a sign of
Associated with infections elsewhere especially lungs
90
Name the 2 form of inflammatory bowel disease
1. Ulcerative colitis
2. Crowns disease
(But can be hard to differentiate between the 2)
91
What are inflammatory bowel diseases?
They are chronic idiopathic inflammatory diseases
92
What does ulcerative colitis usually effect?
The colon
93
What is ulcerative colitis
Inflammation of the rectum followed by CONTINUOUS inflammation through the large bowel
94
Where is inflammation caused by ulcerative colitis often confined to?
Confined to the most superficial layer of the bowel wall
95
Talk through some extra gastrointestinal manifestation of ulcerative colitis
1. Skin: pyoderma gangrenosum
2. Joints: large joint arthritis, ankylosing spondylitis
3. Liver: primary sclerosing cholangitis
96
How do we treat ulcerative colitis
Removing the colon
97
Where can crohns disease arise?
From mouth to anus
98
Describe the inflammation caused by crohns disease
DEEP inflammation that tends to be patchy
99
State the histological hallmark for crohns disease
Non caseating granulomas
100
What are granulomas?
Aggregations of certain inflammatory cells
