Skin conditions Flashcards
(108 cards)
1
Q
What are some broad types of psoriasis?
A
- Psoriasis vulgaris (plaque)
- Pustular psoriasis
- Psoriatic erythroderma
2
Q
What are the 5 defining features of psoriatic rash?
A
- erythematous
- well-circumscribed
- scaly
- plaques
- symmetrical
3
Q
What are the subtypes of psoriasis vulgaris?
A
- Guttate
- Inverse
- Chronic stable plaque
- Palmoplantar
4
Q
What is psoriasis?
A
A chronic immune disorder with polygenic predisposition plus environmental triggers that cause patient to develop plaques due to overproduction and increased turnover of keratinocytes. The disease is T-cell mediated (Th1 response).
5
Q
What precipitates psoriasis in general?
- What precipitates guttate psoriasis?
A
In general, physical trauma (scratching/rubbing), stress, drugs, alcohol or environmental factors elicit psoriatic lesions.
- GAS infection triggers guttate psoriasis
6
Q
Which lymphocytes are found in psoriatic lesions?
A
CD8 T-cells
7
Q
What is intertrigo?
A
Infection (bact/viral/fungal) causing inflammation of the skin folds - developed at the site of broken skin.
8
Q
What nail changes are seen with psoriasis?
A
- symmetrical pitting
- onycholysis
- subungual hyperkeratosis
- yellow/brown “oil spot” *pathognomonic
9
Q
What is acanthosis?
A
Diffuse epidermal thickening.
10
Q
If a fungal infection is suspected, what test should be done?
A
KOH test!
11
Q
What is Tinea veriscolour?
A
Infection caused by Malassezia furfur.
Produces red/gray scaly pruritic patches anywhere on skin.
12
Q
What is “the itch that rashes”?
A
Atopic dermatitis (Eczema)
13
Q
What is the significance of testosterone with respect to balding pattern in androgenetic alopecia?
A
Testosterone is metabolized (by 5-alpha reductase) to DHT on scalp and this causes balding.
14
Q
What is the treatment for androgenetic alopecia?
A
finsteride PO, topical minoxidil solution, or hair transplantation
15
Q
What are exclamation point hairs pathognomonic for?
A
Alopecia areata
16
Q
What is alopecia areata?
A
- autoimmune disease;
- circumscribed circular patch of baldness
- may be asymptomatic or have paresthesias or tenderness
17
Q
What is atopy?
A
predisposition to developing allergic hypersensitivity
18
Q
What causes scarring hair loss?
A
- Lupus
- Lichen planopilaris
19
Q
What is the clinical diagnosis for someone who shows repetitive pulling/plucking of his/her hair?
A
Trichotillomania
20
Q
What is it called when a patient repetitively swallows his/her hair?
- what is the harm in this?
A
Trichophagia
- may form trichobezoar which can cause partial obstruction of the intestine
21
Q
What is the term for decrease or complete discontinuance of proliferation of matrix cells of the hair shaft?
- what is a cause for this condition?
A
Anagen effluvium (ie. loss of growth phase hairs) - caused by chemo/radiation
22
Q
What are the phases of hair growth?
A
Anagen - growth phase;
Catagen - transition phase (club hairs);
Telogen - resting phase.
23
Q
What is telogen effluvium?
- how long does it take for the hair to grow back?
A
Hair enters the telogen (resting phase) before it should –> escessive hair shedding
- normal regrowth in 6 months
24
Q
If you see spoon-shaped nails, what is the likely diagnosis?
A
Fe-deficiency
25
What is the treatment for pemphigus vulgaris?
High-dose steroids
26
What is pemphigus vulgaris?
| - how does the main clinical symptom develop?
Ab-mediated disorder:
- Ab targets Ag in desmosomes that connect keratinocytes
- causes stratum spinosum to lift off of stratum basale
- forms flaccid bullae that is easily ruptured.
27
What are the 5 P's for characterizing lichen planus?
```
Pruritic
Purple
Planar
Polygonal
Papules
```
28
What is bullous pemphigoid?
Ab-mediated blistering disease (of the elderly)
| - Ab targets Ag at dermal-epidermal jxn
29
What are the pathological features of acne?
- Keratin buildup at surface of hair follicles
- overproduction of sebum from sebaceous glands
- inflammation in/around hair follicles
- fibroblast proliferation & collagen deposition
30
What is the name of the muscle that causes piloerection?
arrector pili
31
What part of the hair follicle is the isthmus?
from sebaceous gland entrance to attachment of arrector pili muscle
32
What part of the the hair follicle extends from the follicular orifice to the sebaceous duct entrance?
follicular infundibulum
33
What are some causes of papulosquamous (ie. papules & plaques with scales) eruptions on the skin?
- psoriasis
- pityriasis rosea
- fungal (tinea)
- nummular dermatitis
-
34
What type of skin lesion has rolled borders?
Basal cell carcinoma
35
What type of skin lesion manifests as a translucent nodule or plaque?
Basal cell carcinoma
36
What are the treatment options for basal cell carcinoma?
1. Electrodessication and curettage
2. Simple surgical excision
3. Micrographic surgery (simultaneous microscopic analysis)
4. Radiation
37
What is the transition stage from actinic keratosis to squamous cell carcinoma called?
Squamous cell carcinoma in situ
| Bowen's disease
38
What are treatment options for actinic keratosis?
1. Liquid nitrogen cryotherapy
| 2. Topical 5-FU
39
Which type of skin cancer is most likely to metastasize?
Squamous cell carcinoma
40
What cell type do basal cell carcinomas arise from?
Keratinocytes
41
What cell type do melanomas arise from?
Melanocytes
42
What cell type do squamous cell carcinomas arise from?
Keratinocytes
43
What are the stages of mole development?
| - briefly describe each
1. Junctional phase (flat, epidermal, pigmented)
2. Compound phase (raised, pigmented, both epidermis & dermis)
3. Dermal phase (raised, loss of hyperpigmetation, dermis)
44
What causes the development of freckles?
Activation of melanocytes.
All typical freckles are caused by sun damage.
45
What causes nevi?
Lots of cell division - increased number of melanocytes.
46
What is the most significant predictor of melanoma risk?
Number of banal (common) nevi
47
What is the best biopsy method for melanoma?
Elliptical excision
48
What is the most important prognostic factor for melanoma?
Depth
49
What are the types of melanoma?
- Superficial spreading melanoma
- Nodular melanoma
- Lentigo maligna melanoma
50
What type of melanoma develops from a nevus?
Superficial spreading melanoma
51
What type of melanoma arises without an onions precursor lesion?
Nodular melanoma
52
What type of glands secrete into hair follicles?
Sebaceous glands & Apocrine glands
53
What type of gland plays the largest role in thermoregulation?
Eccrine glands
54
What is holocrine secretion?
Secretions are made in the cytoplasm and are released when the plasma membrane ruptures and the cell dies.
55
What is merocrine secretion?
- what type of gland uses merocrine secretion?
Secretion are excreted from the cell by exocytosis.
Eccrine glands exhibit merocrine secretion.
56
What is apocrine secretion?
Secretions are released be membrane budding.
57
Where are apocrine glands located?
Axilla, groin,
58
Histologically, what is different about the skin of the nose?
Large sebaceous glands.
59
Histologically, what is different about the skin of the back?
Thick reticular dermis
60
Histologically, what is different about the skin of the palms and soles?
- Thick stratum corneum
- numerous eccrine glands
- nerve end organs
- glomus bodies
- no pilosebaceous units
61
What is the name for the thick skin on the palms and soles?
Acral skin
62
The dermal papillae interdigitate with what epidermal structures?
Rete ridges
63
Where are hemidesmosomes found in the skin?
Attaching the keratinocytes in the stratum basale to the basement membrane.
64
What makes the stratum granulosum appear granulated?
Keratohyaline granules found in the flattened keratinocytes.
65
What is the embryonic origin of keratinocytes?
Ectoderm
66
What filaments are found in keratinocytes?
Tonofilaments (composed of keratin intermediate filaments)
67
Where in the skin are melanocytes normally found?
- what happens in melanoma?
Basal layer
- in melanoma, melanocytes migrate into spinousum & granulosum (melanoma in situ); melanocytes then migrate through basement membrane to dermis (malignant).
68
What is the embryonic origin of melanocytes?
Neural crest cells
69
How is melanin synthesized?
Tyrosine --> DOPA --> dopaquinone --> melanin
70
What is the difference in dark skinned vs. light skinned individuals?
Darker skinned individuals have increased melanogenesis --> increased number of melanin granules but no increase in number of melanocytes.
71
What type of granules are found in Langerhans cells?
| - what is their function
Birbeck granules
| - degradation of Ag & Ag presentation
72
Where in the body are Merkel cells mostly found?
Thick skin of palms & soles, mucous membranes of lips & oral cavity
73
What cells are present in the dermis?
- fibroblasts
- dermal dendritic cells
- mast cells
- histiocytes (macrophages)
- sometimes lymphocytes
74
What connects the lamina densa of the dermis to the basement membrane?
Anchoring filaments containing type VII collagen
75
What are the major components of the basement membrane?
Laminin & type IV collagen
76
Which part of the dermis contains more elastin fibres?
Reticular dermis
77
What is a glomus body?
Arteriovenous shunts in fingertips and external ear - surrounded by specialized muscle sphincters that are temperature dependent.
78
What are encapsulated nerve endings responsible for?
Sensation of touch
79
What are free nerve endings responsible for?
Sensation of pain and temperature
80
What are the components of the pilar unit?
- hair follicle
- sebaceous gland
- arrector pili muscle
- apocrine gland (when present)
81
What is verruca vulgaris?
- what is usually the cause of it?
```
Connor warts (raised wart with roughened surface, usually on hand)
- cause is usually viral (HPV)
```
82
What is the embryonic origin of the dermis?
Mesoderm
83
What happens in bullous pemphigoid?
Ab to hemidesmosomes - epidermis tears off the dermis
84
What is the main diffusion barrier in the skin?
| - what are the two compartments of this structure?
Stratum corneum.
| Made of protein-rich corneocytes & lipid-rich intercellular matrix.
85
What is filaggrin?
| - what are filaggrin mutations associated with?
Filaggrin is a protein (formed from profilaggrin in the keratoahyaline granule) that helps in the assembly of keratin in corneocytes.
Filaggrin mutations are associated with atopic dermatitis.
86
What type of UV radiation causes sunburn?
UVB
87
What type of UV radiation penetrates deeper into the skin?
UVA
88
What is the affect of UVA radiation?
Cytotoxic free radical production.
89
What are the skin's primary barriers to UV radiation?
- Protein barrier in the stratum corneum
| - Melanin barrier dispersed throughout epidermis
90
What are the functions of melanin?
- protect from UV radiation
- scavenging cytotoxic radicals
- neurological development
91
What is the life cycle of a melanosome?
Synthesized by melanocytes, transported along cell processes (dendrites), phagocytosed by keratinocytes, fusion with lysosomes.
92
Where in the body are glomus bodies found?
In exposed areas:
| Hands, feet, ears.
93
What is the innervation of eccrine sweat glands?
Sympathetic cholinergic.
| - will also respond to blood-borne adrenergic stimulation during sweating.
94
What is the name of the condition with absent/defective sweat glands?
Ectodermal dysplasia
95
What is erythromelalgia?
Mutation in Na+ channel associated with nerve conduction.
96
At what age does pityriasis rosea most commonly present?
Age 10-20
97
What is spongiosus?
| - what is it associated with?
Intraepidermal intercellular edema.
- seen in eczematous processes
98
What infectious agent is scarlet fever usually linked to?
Steptococcus
99
What infectious agent is associated with boils, carbuncles, & faruncles?
Staphylococcus
100
What are some dermatological issues that are related to Staph infection?
- farunculosis
- folliculitis
- impetigo
101
What age-group is most commonly affected by impetigo?
Pre-school aged children
102
What is the most common cause of allergic contact dermatitis?
Nickel
103
What is the microscopic description of a wart?
vacuolation of keratinocytes in the upper epidermis, a basket weave stratum corneum, and koilocytosis (description taken from week quiz on Medicol)
104
What is the causative agent of roseola infantum?
HHV6
105
For which conditions is Wood's light used as a diagnostic tool?
- Tinea capitus
- Erythrasma
- Vitiligo
106
What diagnostic tool is used for suspected scabies infection?
Oil microscope
107
What diagnostic test is done for suspected herpes (zoster, simplex, or varicella)?
- what indicates a positive result?
Tzank
- positive result is presence of multi-nucleated giant keratinocytes
108
What diagnostic test is used for suspected syphilis?
Darkfield exam
