Inflammatory Skin & Tumours Flashcards
1
Q
What are the 4 major types of tissue reaction patterns seen in inflammatory skin disease?
A
- Spongiotic reaction pattern
- Psoriasiform reaction pattern
- Lichenoid reaction pattern (’interface dermatitis’)
- Vesiculobullous reaction pattern
2
Q
What type of tissue reaction pattern is ‘eczema’?
A
Spongiotic reaction pattern
3
Q
What type of tissue reaction pattern is ‘psoriasis’?
A
Psoriasiform reaction pattern
4
Q
What type of reaction pattern is Licen planus?
A
Lichenoid reaction pattern
5
Q
What type of reaction pattern is lupus erythematosus?
A
Lichenoid
6
Q
What type of reaction pattern is lupus erythematosus?
A
Lichenoid
7
Q
What are the 3 clinical stages of eczema? Describe the appearance of the skin for each
A
- Acute dermatitis; skin red, weeping serous exudate +/- small vesicles
- Subacute; skin is red, less exudate, itching ++, crusting
- Chronic; skin thick and leathery secondary to scratching
8
Q
What characterises a ‘spongiosis’ reaction?
A
Characterised by intercellular oedema within the epidermis (spongiosis)
9
Q
How is the epidermis affected in chronic eczema?
A
Epidermal hyperplasia and hyperkeratosis – mild in acute dermatitis, marked in chronic dermatitis
10
Q
What other 2 conditions is atopic eczema typically associated with?
A
Asthma and hayfever
11
Q
What type of hypersensitivity reaction is atopic eczema?
A
Type 1 reaction to allergen
12
Q
Define atopic
A
denoting a form of allergy in which a hypersensitivity reaction such as eczema or asthma may occur in a part of the body not in contact with the allergen.
13
Q
What are the 2 types of contact dermatitis?
A
- Contact irritant
- Contact allergic
14
Q
mechanism behind contact irritant dermatitis?
A
direct injury to skin by irritant
15
Q
What irritants can cause contact irritant dermatitis?
A
acid, alkali, strong detergent, etc
16
Q
Mechanism behind contact allergic dermatitis? What hypersensitivity reaction is this?
A
- Act as haptens which combine with epidermal protein to become immunogenic
- This is a delayed ‘type 4’ hypersensitivity reaction
17
Q
What allergens are responsible for contact allergic dermatitis?
A
Nickel, dyes, rubber
18
Q
What are the 2 morphological subtypes of ‘dermatitis of unknown aetiology’?
A
- Seborrhoeic dermatitis
- Nummular dermatitis
19
Q
What areas does seborrhoeic dermatitis affect?
A
affect areas rich in sebaceous glands: scalp, forehead, upper chest
20
Q
How does nummular dermatitis appear?
A
Coin shaped lesions
21
Q
Presentation of psoriasis?
A
- Well defined, red oval plaques on extensor surfaces; knees, elbows, sacrum
- Fine silvery scale
- ‘Auspitz sign’
- +/- sero-negative arthritis
- Oral manifestations
- Can cause alopecia
22
Q
What is an ‘Auspitz sign’?
A
refers to a bleeding point that can occur when the surface of a scaling rash has been removed
23
Q
What is parakeratosis?
A
Parakeratosis is defined as the presence of nucleated keratinocytes in the stratum corneum
24
Q
What is the histological appearance of psoriasis?
A
“Psoriasiform hyperplasia”
- i) Regular elongated club shaped rete ridges
- ii) Thinning of epidermis over dermal papillae.
- iii) Parakeratotic (contain nuclei) scale.
- iv) Collections of neutrophils in scale (Munro micro abscesses)
25
What are Munro micro abscesses?
This is a collection of neutrophils (abscess) in the **stratum** **corneum** of the epidermis due to infiltration of neutrophils from papillary dermis.
26
Describe the cell turnover time in psoriasis
Massive cell turnover --\> causes clinical and microscopic features
27
Environmental trigger factors for psoriasis?
Infection, stress, trauma, drugs
28
What are the psoriasis susceptibility genes?
PSORS genes (many in region of major histocompatibility complex on Chromosome 6p2 implicated)
29
Associated co-morbidities of psoriasis?
* Arthropathy, 5-10% associated
* Psychosocial effects
* Cardiovascular disease; 2-3x risk.
* May be due to inflammation/drugs/stress/smoking
* Increased risk of non-melanoma skin cancer e.g. BCC, lymphoma
30
How do the treatment and asociated comorbidity risk of skin cancer conflict in psoriasis?
One main treatment of psoriasis is UV light --\> increases risk of non-melanoma skin cancer
31
What characterises a 'Lichenoid' reaction pattern?
Characterised by epidermal **_basal cell_** damage
32
What is Lichen planus?
Lichen planus is an inflammatory skin condition, characterised by an itchy, non-infectious rash that affects the flexor surfaces, mucous membranes and genitals
33
What type of hypersensitivity reaction is Lichen planus?
Type 4
34
How long does Lichen planus typically last?
1-2 years but longer in oral cavity
35
What other conditions can Lichen planus be associated with?
Viral hepatitis, HIV (and some drugs)
36
What is lupus erythematosus?
* Auto-immune disorder primarily affecting connective tissues of the body; connective tissue disorder
* May affect any part of the body, but importantly **kidneys** (major predictor of outcome)
37
What is the type of lupus that affects the **skin** only?
Discoid lupus erythematosus (SDE)
38
how does DLE present?
Red scaly patches on sun-exposed skin +/- scarring, scalp involvement causes alopecia.
39
What is the characteristic facial feature of SLE?
Butterfly rash on cheeks and nose
40
What type of hypersensitivity reaction is lupus?
Type III
41
What is epidermal atrophy?
Epidermal atrophy is characterised by the **reduction** in the number of **epidermal** **cells** leading to the **reduced** **thickness** of the epidermis.
42
How does lupus erythematosus present microscopically?
* Thin atrophic epidermis
* Inflammation and destruction of adnexal structures.
* **IgG** deposited in **basement** **membrane**
43
Which antibody is deposited in basement membrane in lupus?
IgG
44
Which technique gives the best diagnostic yield in lupus?
Direct **_immunofluorescence_** (DIF) of skin in conjunction with histopathology gives the best diagnostic yield
45
What type of reaction pattern is dermatomyositis?
Lichenoid
46
What is dermatomyositis? What do symptoms include?
Dermatomyositis is an autoimmune condition that causes skin changes and muscle weakness.
Symptoms;
* Peri-ocular oedema and erythema (Heliotropic rash)
* Erythema in photosensitive distribution
* Myositis; proximal muscle weakness (check for creatinine kinase)
47
In adults, what are 25% of dermatomyositis cases associated with?
Underlying **visceral cancer**
48
Microscopy of dermatomyositis?
* Similar to lupus
* Often a lot of dermal mucin
49
What characterises a vesiculobullous reaction pattern?
The vesiculobullous reaction pattern is characterised by the presence of **vesicles** or **bullae** (fluid filled blisters) at any level within the epidermis or at the dermoepidermal junction.
50
What type of reaction pattern in pemphigus?
Vesiculobullous reaction pattern
51
What type of reaction pattern in pemphigoid?
Vesiculobullous reaction pattern
52
What is pemphigus/pemphigoid?
* Pemphigus is a group of skin disorders that cause blisters or pus-filled bumps.
* **Autoimmune.**
* Can be detected by immunofluorescence (IMF)
* Can be localised or extensive
53
Pemphigus vs pemphigoid;
a) location of blisters?
b) deposition of autoantibodies?
Pemphigus;
a) intra-epidermal blisters
b) intercellular deposition of autoantibodies
Pemphigoid;
a) sub-epidermal bullae
b) Deposition of autoantibodies at basement membrane
54
Describe the difference in blisters present in pemphigus vs pemphigoid?
Pemphigus - affects the outer of the skin (epidermis) and causes lesions and blisters that are easily ruptured (very fragile).
Pemphigoid - affects a lower layer of the skin, between the epidermis and the dermis, creating tense blisters that do not break easily.
55
How are blisters formed in pemphigus?
Group of disorders characterised by **loss of cohesion between keratinocytes** resulting in an **intraepidermal** blister.
56
Pathogenesis behind pemphigus vs pemphigoid?
* Pemphigus - Autoantibodies directed against intercellular material.
* Pemphigoid - Autoantibodies to **glycoprotein** in **basement membrane**
57
Which age group is pemphigus/pemphigoid more commonly seen in?
Elderly
58
What type of tissue reaction pattern is dermatitis herpetiformis?
Vesiculobullous reaction pattern
59
What is dermatitis herpetiformis? Symptoms?
* A rare, chronic, **autoimmune** skin condition
* Symptoms;
* severely itchy blisters
* raised red skin lesions
60
What age group does dermatitis herpetiformis usually affected?
Young patients
61
What disease is dermatitis herpetiformis associated with?
Coeliac disease
62
In which inflammatory skin condition is there **IgA deposition** in the **dermal papillae** on IMF?
Dermatitis herpetiformis
63
Histopathology of dermatitis herpetiformis?
Neutrophil microabscesses in dermal papillae
64
Skin lesions can be signs of systemic disease. What underlying pathology can the following skin conditions indicate;
a) dermatomyositis
b) dermatitis herpetiformis
c) Acanthosis Nigricans (dark warty lesions in armpits)
d) Necrobiosis Lipoidica (red + yellow plaque on legs)
e) Erythema Nodosum (red tender nodules on shins)
a) visceral cancer
b) Coeliac disease
c) internal malignancy
d) diabetes mellitus
e) associated with infections elsewhere especially lung, drugs, and other diseases
65
Which inflammatory skin condition is characterised by epidermal hyperplasia and hyperkeratosis?
Chronic dermatitis
66
Which type of dermatitis affects areas rich in sebaceous glands: scalp, forehead, upper chest?
Seborrhoeic dermatitis
67
Which type of dermatitis presents with coin shaped lesions?
Nummular
68
Which type of inflammatory skin condition can present with 'Auspitz signs'?
Psoriasis
69
Which type of inflammatory skin condition can present with a fine silvery scale?
Psoriasis
70
Which type of inflammatory skin condition can present with parakeratosis?
Psoriasis
71
Which type of inflammatory skin condition can Munro micro abscesses?
Psoriasis
72
Which type of inflammatory skin condition involves massive cell turnover?
Psorasis
73
Which type of reaction pattern is characterised by epidermal basal cell damage?
Lichenoid
74
Which type of inflammatory skin condition is associated with viral hepatitis or HIV?
Lichen planus
75
Which type of inflammatory skin condition can present with IgG deposited in basement membrane?
Lupus
76
Which type of inflammatory skin condition can present with a thin atrophic epidermis?
Lupus
77
Which type of inflammatory skin condition can present with peri-ocular oedema?
Dermatomyositis
78
Which type of inflammatory skin condition can present with proximal muscle wasting?
Dermatomyositis
79
Which type of inflammatory skin condition is caused by a loss of cohesion between keratinocytes?
Pemphigus
80
Which type of inflammatory skin condition is caused by autoantibodies to glycoprotein in basement membrane?
Pemphigoid
81
Which type of inflammatory skin condition can present with IgA deposition in dermal papillae?
Dermatitis herpetiformis
82
Which type of inflammatory skin condition can present with neutrophil micro abscesses in dermal papillae?
Dermatitis herpetiformis
83
What is the commonest malignant skin tumour?
Basal cell carcinoma
84
Does BCC tend to metastasise?
no
85
Aetiology of BCC?
* Sun exposed site, especially face
* Occasional secondary to radiotherapy
* Pale skin that burns easily
* Immunosuppression
* Rare; Gorlin’s syndrome (increases risk of developing various cancerous and non-cancerous tumours)
86
What is Gorlin's syndrome?
a condition that affects many areas of the body and increases the risk of developing various cancerous and noncancerous tumors.
87
Presentation of BCC lesion?
rodent ulcer with rolled edge
88
Microscopically, what would a tumour composed of islands of **basaloid** **cells** with **peripheral** **palisade** indicate?
BCC
89
What cell type does squamous cell carcinoma arise from?
Keratinocytes
90
Causes of SCC?
* U.V. irradiation
* Usually occurs in sun exposed sites
* Increased risk in tropical countries.
* Radiotherapy
* Hydrocarbon exposure - tars, mineral oils, soot
* Percival Pott noted SCC scrotum in chimney sweeps
* Chronic scars/ulcers - SCC arises within these (Marjolins ulcer).
* Immunosuppression - renal transplant patients at increased risk.
* Drugs, some newer drugs for melanoma (BRAF inhibitors)
91
Presentation of SCC lesion?
Nodule with ulcerated, crusted surface
92
Microscopically, what would invasive islands and trabeculae of squamous cells showing cytological atypia indicate?
SCC
93
What is known as the 'pre-malignant' form of SCC?
Actinic (solar) keratosis --\> dry scaly patches of skin that have been damaged by the sun;
* Dysplasia to squamous epithelium
* Very common on chronic sun exposed sites.
* Scaly lesion with erythematous base
* Only **rarely progresses** to invasive disease.
* May spontaneously resolve
94
Where are melanocytes derived from?
Neural crest
95
Function of melanocytes?
To form **melanin** which is transferred to epidermal cells **to protect the nucleus** **from UV radiation**
96
Melanocytes can give rise to benign or malignant tumours. What are the names of each?
Benign - naevi (moles)
Malignant - melanoma
97
What are naevi?
* Local benign collections of melanocytes
* Diameter \<6mm
* Several types;
* Superficial; congenital or acquired
* Deep; **blue** **naevi** (mongolion spot)
98
What is atypical mole syndrome? What can it increase your risk of?
* Multiple clinically atypical moles
* Histologically atypical/dysplastic naevi
* Increased risk of developing **melanoma**
99
Does melanoma metastasise?
Very dangerous malignancy which can metastasise widely
100
Size of melanoma lesion?
\>6mm
101
Aetiology of melanoma?
* a) **Sun exposure** - especially short intermittent severe exposure
* b) **Race** - Celtic with red hair, blue eyes, fair complexions who tan poorly most at risk. Melanoma rare in dark skinned people.
* c) **Family** **history** – Atypical mole syndrome (multiple large atypical moles)
* d) **Giant congenital naevi** - small risk of turning malignant (\<5%)
102
What is the most common form of melanoma?
**Superficial spreading melanoma** --\> a type of skin cancer that slowly grows horizontally across the top layer of skin before moving to the deeper layers (Proliferation of atypical melanocytes which invade epidermis and dermis).
103
What specific gene mutation havs been detected in many superficial spreading melanomas?
BRAF mutations (target for anticancer agents)
104
Microscopy of **nodular** melanoma?
Invasive atypical melanocytes invade dermis to produce nodules of tumour cells.
105
What is lentigo maligna?
* Lentigo maligna is an early form of **melanoma** in which the malignant cells are confined to the tissue of origin
* Typically arises on face in elderly people
* Slow growing, flat, pigmented patch
106
Microscopy of lentigo maligna?
* Micro: Proliferation of atypical melanocytes along basal layer of epidermis. Skin also shows signs of chronic sun damage.
* Late in disease, melanocytes may invade dermis (lentigo maligna melanoma) with potential to metastasise.
107
Are BRAF mutations seen in lentigo maligna?
Typically no
108
What is acral lentiginous melanoma?
is a type of melanoma arising on the palms or soles (occasionally sublingual)
109
What is the commonest form of melanoma in afro-carribeans?
Acral lentiginous melanoma
110
Microscopy of acral lentiginous melanoma?
Micro: Similar to lentigo maligna except no marked sun damage.
111
Naevus vs melanoma
112
What is pagetoid spread?
An individual cell proliferation in the upper levels of the epidermis.
113
Which type of melanoma exhibits pagetoid spread?
Superficial spreading melanoma
114
60% melanoma’s have mutation in which gene?
BRAF
115
What syndrome can be associated with an increased risk of BCC?
Gorlin's syndrome
116
What is a heliotrope rash? What condition is it associated with?
* A heliotrope rash is a reddish purple rash on or around the eyelids
* Heliotrope rash is caused by dermatomyositis
