Introduction to Dermatology 2 Flashcards
1
Q
What external factors does the hair help protect against?
A
UV, things which may be crawling on us
2
Q
What is the pilosebaceous unit?
A
the hair shaft, the hair follicle, the sebaceous gland, and the erector pili muscle
3
Q
What does the pilosebaceous unit produce?
A
Sebum (oil)
4
Q
What are the functions of the hair?
A
- Sexual /social interaction
- Source of epithelial and melanocyte stem cells
- Apocrine swear which is involved in thermoregulation
- Sebum production
- Protection against external factors
5
Q
Where are terminal hairs found?
A
Scalp, eyebrows and eyelashes
6
Q
Where are the vellus hairs found?
A
Found on the rest of the body, with the exception of the palms, soles and external genitalia, mucosal region of lips
7
Q
What are the hairless genitalia in men and women?
A
Men - foreskin of the penis
Women- Labia minora
8
Q
What are the three stages of the hair cycle?
A
Anagen
Catagen
Telogen
9
Q
What phase of the hair cycle most of our hair in at any given time?
A
The anagen phase
10
Q
How long does the anagen phase of the hair cycle last?
A
Lasts 2-6 years
11
Q
What occurs in the catagen phase?
A
When the hair is shrinking / regressing back into the follicle
12
Q
How long does the catagen phase last?
A
Lasts 3 weeks
13
Q
What happens in the telogen phase?
A
The resting phase - hair is neither growing or shrinking
14
Q
During states of illness, in what phase of the hair cycle can an increase in the amount of hair in this cycle be seen?
A
The telogen phase
15
Q
How long does the telogen phase of the cell cycle last?
A
3 months
16
Q
What happens to the hair after the telogen phase comes to a end?
A
The hair detaches and is lost
17
Q
What are hair follicles?
A
Pockets of epithelium that are continuous with superficial epidermis
18
Q
What is found at the base of a hair follicle?
A
A dermal papilla, made of dermis
19
Q
Where does the arrector pili extend from?
A
The surface of the dermis to a point in the follicle wall
20
Q
What is the purpose of the arrector pili muscle?
A
When they contract, they cause the hair to stand up
21
Q
What type of muscle is the arrector pili?
A
Smooth muscle - controlled by autonomic nervous system
22
Q
What type of secretion do sebaceous glands support?
A
Holocrine section
23
Q
Where do the holocrine sebaceous glands open into?
A
pilary canal
24
Q
In the axillae, what type of secretion are the glands found there associated with?
A
Apocrine glands
25
What are the two parts of the hair follicle?
Infundubulum and Isthmus
26
From what point does the infundubulum extent to and from?
The sebaceous gland to the surface of the skin
27
What points does the isthmus extend from?
Between the opening of the sebacous gland and the insertion of arrector pili muscle
28
What does epithelial keratinization begin with?
A lack of granular layer
29
What is trichilemmal keratinization?
Epithelium keratinisation begins with lack of granular layer names “trichilemmal keratinisation”
30
Where is the bulge located?
Just below the sebaceous gland
31
What cells reside in the bulge?
hair follicle stem cells
32
What forms when hair follicle stem cells migrate downwards?
New lower anagen hair follicles - they enter the hair bulb matrix, proliferate and undergo terminal differentiation to form hair shaft and inner root sheath
33
What forms when the hair follicle stem cells migrate upwards?
Form the sebaceous gland
34
Why are hair follicle stem cells important in injury?
They proliferate in response to wounding, and help healing response
35
What is the bulb?
The lower most portion of the hair follicle which includes the follicular dermal papilla and the hair matrix
36
What is the matrix?
The principal place where the hair shaft is being produced
37
What does the outer root sheath do?
Serves as a reservoir of stem cells
38
Where does the outer root sheath extend from?
From along the hair bulb to the epidermis
39
What is the purpose of the inner root sheath?
To guide and shape the hair
40
What is contained with the inner root sheath?
Follicular dermal papilla. mucopolysaccharide-rich strome, nerve fibre and capillary loop
41
What is the purpose of the mucopolysaccharide-rich strome found in the inner root sheath?
To give the inner root sheath strength
42
What do the nails protect?
The underlying distal phalanx
43
What are the functions of the nails?
1. Protects underlying distal phalanx
2. Counterpressure effect - important for walking and tactile sensation
3. Increase dexterity / manipulation of small objects
4. Enhance sensory discrimination
5. Facilitate scratching / grooming
44
What is the nail plate?
The final product of proliferation and differentiation of nail matrix keratinocytes
45
What does the nail plate emerge from?
Proximal nail fold
46
What is the growth rate of the nail plate?
1-3mm a month
47
What is the point at which the nail plate detaches from the nail bed called?
Hyponychium
48
Where is the nail plate manufactured?
In the nail matrix
49
What is the lunula?
only visible portion of the nail matrix
50
Where is the nail matrix found?
Underneath the proximal nail fold, above bone of distal phalanx
51
How does the nail grow in the nail matrix?
Nail matrix keratinocytes differentiate, lose their nuclei and become filled with hard keratin and fill with hard keratin
52
What does the nail matrix contain as well as keratinocytes?
Melanocytes
53
Are the melanocytes found in the nail matrix active?
No
54
What is an erythema?
A red, raised and large area of inflammed skin
55
What type of disorder is Psoriasis?
An immune mediated disorder
56
What features characterise the most common features of psoriasis?
Sharply demarcated, scaly, erythematous plaques, silvery plaques
57
What are common sites for psoriasis flareups to occur?
Scalp, elbows, knees, nails, hands, feet and trunk
58
What causes psoriasis?
Polygenic predisposition combined with environmental triggers eg trauma, infection or medication
59
Describe how dermal dendritic cells are activated in the pathophysiology of Psoriasis?
Stressed keratinocytes release DNA which forms complexes with anti-microbial peptides
This induces cytokine production to activate the dermal dendritic cells
60
Describe how the formation of dermal dendritic cells leads to the formation of a psoriasis plaque?
dDC's migrate to the lymph nodes, and promote the release of cytokines from Th1, Th17 and Th22 cells
These migrate into the dermis and cause further cytokine production which causes the keratinocytes to proliferate and form a psoriasis plaque
61
When dDC's migrate to the lymph nodes, which T helper cells are activated?
Th1, Th17 and Th22
62
When stressed keratinocytes release DNA and form complexes with antimicrobial peptides, the release of which cytokines is initiated?
TNF-alpha, IL-1 and IFN-alpha
63
What are some clinical features of psoriasis?
- Erythemas - may appear as pigmented areas on darker skin tones
64
Why might you not see scales in areas of flexure?
Skin meets skin, and therefore due to friction there might not be scales present
65
How is it possible to get psoriasis of the nails?
nails are made of nail matrix which contains keratinocytes, so can develop psoriasis
66
What does psoriasis of the nails indicate?
That the patient is of increased risk of psoriatic arthiritis
67
What is thickening under the nail called?
Subungual hyperkeratosis
68
What is Onycholysis?
Detachment of the nail from the nail plate
69
What is Erythrodermic psoriasis?
When you have a peeling rash covering more than 95% of your body surface area
70
What is guttate psoriasis?
psoriasis that appears as small, round spots called papules that are raised and sometimes scaly.
71
What lifestyle factors worsen psoriasis?
Alcohol, smoking and other co-morbidities
72
What psychological conditions are you at an increased risk of when you suffer from psoriasis?
Suicide, depression and anxiety
73
What other areas of your body might psoriasis affect?
Mental health, joints
74
What are four topical therapies used to manage psoriasis?
Vitamin D analogues
Topical corticosteroids
Retinoids
Topical tacrolimus / pimecrolimus (immunosuppresants)
75
When are topical therapies used to manage psoriasis?
When you have small patches of psoriasis over the body
76
When is phototherapy chosen as a treatment for psoriasis?
When the psoriasis is too widespread over the body
77
What does phototherapy involve?
Using Narrow band UVB rays to treat psoriasis
78
What is Acitretin?
A vitamin A anaologue
79
What are two systemic immunosuppresive drugs that can be given to treat psoriasis?
Methotrexate
Ciclosporin
80
How are biologics used to treat psoriasis?
Anti-TNF, anti-IL-17 and anti-IL23 (these are all cytokines which are important in the onset of psoriasis
81
What is eczema?
A chronic, inflmmatory condition which typically begins during infancy or early childhood, and is often associated with other atopic disoders like asthma and rhinoconjunctivitis
82
What are the hallmarks of eczema
Acute inflammation of cheeks, scalp and extensors in children, and flexural inflammation and lichenification in children and adults
83
What is eczema cmmonly referred to as?
Dermatitis
84
What are some different types of eczema?
Atopic eczema, allergic contact eczema, venous stasis eczema, irritant contact dermatitis
85
What is the key defining principle of atopic dermatitis?
Itchy skin
86
What is seborrhoiec eczema?
Dandruff
87
What are the two components of the pathophysiology of eczema?
Barrier defects and immune dysregulation
88
what is the function of filaggrin?
To bind and aggregate keratin bundles and intermediate filaments to form cellular scaffolds in corneocytes
89
What are corneocytes?
Cells found in the stratus cornea
90
What happens when there is a mutation causing the filaggrin to function incorrectly?
There is reduced extracellular lipids and impaired ceramide production
Increased transepidermal water loss
Impaired protection against microbes and environmental allergens
91
What is transepidermal water loss?
Loss of water across the epideral barrier
92
how does immune dysregulation lead to eczema?
Straphylococcal superantigens overstimulate Th2 lymphocyte responses and subvert T-reg cells
93
What happens to the microbiome during eczema?
It is imbalanced
94
What are the clinical features of infantile atopic dermatitis?
Erythematous, oedematous papules and plaques with or without vesiculation
95
How does the area eczema impacts change as you go from infant to child>
Changs from scalp and cheeks to affect the flexures like behind the knees and inner arms
96
what happens to people with pigmented skin during eczema?
Hyperpigmentation
97
What is lichenification?
Thickening of skin and skin lesions
98
What is fissuring?
When you get cracks in the skin forming
99
What is contact dermatitis?
When you get inflammation of the skin due to your skin reacting with something which it has come into contact with
100
What is impetiginisation?
When there is a superficial infection of the skin, usually seen with a gold crust and a Staphylococcus aureus infecion
101
How does venous stasis eczema arise?
Due to a build up of fluid due to venous incompetance of the skin which compromises the barrier, leading to trans epidermal waterloss
102
How do you treat Venous stasis eczema?
Stockings and compression - responds to steroids but doesn't stay responding
103
What condition does someone have when they present with monomorphic punched out erosions with their eczema?
Eczema herpeticum
104
Which type of eczema is considered an emergency?
Eczema herpeticum
105
What soap should eczema patients use?
Dermol 500, with cold showers
106
What does soap do to eczema patients?
Aggrevates the barrier defect
107
What is nipple eczema until proven otherwise?
Pagets disease of the nipple - presents in a very similar manner to eczema so it is always important to be biopsied
108
What can pagets disease suggest?
Breast cancer
109
When might a biopsy of atopic eczema be taken?
If it is on the nipple, or there could be a cutaneous lymphoma
110
What is PUVA used for?
Treating hand dermatitis and some forms of psoriasis
111
What topical therapies can be used for the treatment of eczema?
Topical corticosteroids and topical tacrolimus
112
What unit is used to describe the amount of topical steroids which should be used to treat eczema?
Fingertip units
113
What can the over use of topical steroids cause?
Tachphylaxis (drug tolerance) and adverse effects
114
What is the order of topical steroids in terms of potency?
Hydrocortisone
Clobetasone
Betamethasone
Momentasone
Clobetasol (Dermovate)
115
Which areas are bethmethasone and momentasone used in?
The non-flexure areas of the skin like limbs and trunk in adults
116
Which topical steroid is used when there is lichenification of the skin?
Clobetasol (Strongest)
117
What are the rare effects of topical immunomodulatories?
skin atrophy, folliculitis, exacerbation of acne and rosacea, infection
118
What are the very rare side effects of topical immunomodulatories?
Perioral dermatitis (around mouth), rebound syndrome and allergy to steroid
119
What are the extremely rare effects of topical immunomodulatories?
hormonal imbalance, suppression of hypothalamic-pituitary-adrenal axis, hirsuitism
120
What is hirsuitism?
condition in women that results in excessive growth of dark or coarse hair in a male-like pattern — face, chest and back
121
What is perioral dermatitis?
SKIN RASH around the mouth
122
which type of eczema are retinoids used to treat?
hand Dermatitis
123
What are some drugs used for systemic immunosuppression in the treatment of eczema?
Methotrexate
Ciclosporin
Azathioprine
Mycophenolate mofetil
124
what biologics are used in the treatment of eczema?
Duplimab - Anti-IL-4alpha and anti-IL13
125
When can biologics be used to treat eczema?
When patients have not responded to other treatments
