Dermatology Flashcards
(121 cards)
1
Q
How are drugs absorbed into the skin?
A
By concentration gradient, via Fick’s law
2
Q
How does the concentration gradient work?
A
The higher the concentration gradient on the outside of the membrane, the faster the drug will absorb through to the other side.
3
Q
How does the skin extend the half-life of a medication?
A
By acting as a reservoir.
4
Q
What drugs are most easily absorbed?
A
Lipophillic drugs
5
Q
How do you determine which vehicle to use?
A
Drug solubility, ability to hydrate stratum corneum, and stability of drug
6
Q
To increase penetration, what layer of skin must be hydrated?
A
Stratum Corneum; its harder to get through dry skin.
7
Q
Tinctures, lotions, gels, and aerosols – Convenient for what type of area?
A
Hairy areas; Avoid ointments and creams.
8
Q
Why are wet dressings used?
A
They provide evaporative cooling and cause vasoconstriction.
9
Q
Normal saline and acetic acid - provide what benefit?
A
Wet dressings; evaporative cooling and vasoconstriction.
10
Q
What vehicle provides drying and cooling along with moisture absorption, which creates more surface areas for evaporation?
A
Powders
11
Q
What vehicle is a suspension or solution of a powder in a water vehicle that is both drying and cooling?
A
Lotion
12
Q
What is a solution?
A
Substance dissolved (solute) in another substance (solvent). Stability depends how well its dissolved.
13
Q
What is a gel? What does it contain?
A
Clear, nongreasy, nonstaining, nonocclusive, and quick drying semisolid emulsions.
Contain propylene glycol; good for hair covered areas or the face where patients want to avoid greasy look after application.
14
Q
If lesion is wet, acute, oozing, crustin, or has vesiculations, what must you do?
A
DRY it
15
Q
If a lesion is dry, chronic, scaling, xerotic, or licheenified, what must you do?
A
WET it - creams and ointments
16
Q
What is used in severe dryness?
A
Ointments.
17
Q
What is the most common vehicle used?
A
Creams
18
Q
What vehicle is not very occlusive, but is rubbed in until it vanishes and is suited for non-irritable dermatoses?
A
Cream
19
Q
Describe an ointment.
A
Most are oil in water based.
Used to relieve dryness and brittleness.
Not use in hair covered areas.
20
Q
Your patient presented with a fissured area. What’s the best vehicle to protect area?
A
Ointment. Good for damaged skin to provide occlusion.
21
Q
What is a disadvantage of aerosols?
A
Expensive and less efficient than topical methods.
22
Q
What is an advantage of aerosols?
A
Application doesn’t require contact.
23
Q
What vehicle is most drying?
A
Tinctures
24
Q
What vehicle is least drying?
A
Ointment
25
Your patient has oozing, vesiculous, and crusting lesion. You decide an ointment is the best choice. Are you correct?
No; ointments are for scaling, lichenified, and xerotic lesions.
26
Your patient presents with a scaling, lichenified, and xerotic lesion. You decide a tincture is the best choice. Are you correct? Why?
No, tinctures will exacerbate the dryness.
27
You have prescribed a cream for your patients lesion. Describe the lesions most likely characteristics:
Scaling, lichenified, and xerotic.
28
What is the pharmacologic advantage of a cream?
Leaves concentrated drug on the skin.
29
What is the pharmacologic advantage of an ointment?
Leaves protective, oily film on the skin.
30
What is the pharmacologic advantage of a gel?
Non-staining and gets rid of greasy appearance because it dries fast.
31
How can the make up of a vehicle contribute to microbial growth?
The higher the water content, the more microbes that have the opportunity to grow.
32
Emulsions
Oil in water - greater occlusion than lotion, but less than ointment.
Used on dry skin.
Water in oil - easier to apply; where dry skin predominates.
33
What is the drug of choice for all inflammatory and pruritic eruptions? i.e. Allergic contact dermatitis, atopic eczema, seborrheic dermatitis.
Topical Corticosteroid agents
34
What are CI of topical corticosteroid agents?
| WHY?
Exacerbates acne vulgaris, warts, fungal infections, and ulcers.
Depresses the immune system so can't be used for warts or fungus.
35
What are ADR of topical corticosteroid agents?
Skin atrophy, fine hair, bruising, striae -- ONLY seen when high potency is used.
36
Your patient presents with acne vulgaris and tinea pedis -- Would you prescribe a corticosteroid for this?
No, topical corticosteroids aren't used for fungal infections or acne.
37
What do you consider when selecting form of corticosteroid to use?
Lesion location and type
38
What are minimum and maximum applications for topical corticosteroids?
At least BID but up to QID to recieve maximum benefit.
39
When applying topical corticosteroids to an area of thinner skin, what should you consider?
Absorption will be higher, must prescribe a lower potency.
| Areas: scrotum, axillae, face.
40
What potency topical is used on forearm?
Medium to high potency
41
If a pt has oily skin, would you choose cream or ointment?
Cream
42
Why would you choose an ointment for dry skin over a cream?
Ointments are more occlusive and better absorbed than creams. Preferred on dry skin.
43
Where would you want to use a low potency TC?
Face, scrotum, vulva, and skin folds.
| LOW potency needed.
44
Hydrocortisone valerate is a salt form of hydrocortisone. What potency does this salt form have?
Medium potency.
45
Name 2 low potency TC?
Hydrocortisone 1%
| Desonide 0.05% (Trideslion)
46
Your patient has lesions on the folds of his skin, what is a good medication to use?
Hydrocortisone 1%
| Desonide 0.05% (Trideslion)
47
Name a popular medium potency agent used to treat eczema and psoriasis.
Triamcinolone
48
When is it okay to use a high potency TC?
Lesions that are recalcitrant to medium potency steroids. Also used for flare ups.
49
What is Fluocinonide 0.05%?
High potency TC used for flare ups.
50
Why are ultra high potency TC often not used?
Cause severe inflammation.
| Risk to benefit ratio.
51
What is Clobetasol 0.05%?
ULTRA high potency TC ointment.
| Comes as a cream too - Temovate.
52
MOA Topical Immunomodulators
Inhibits T cell, mast cell, and keratinocytes activation.
53
TIM's are DOC for?
atopic dermatitis and chronic inflammatory skin disease.
54
TIMs medications are used as an alternative to TC. Why are they preferred?
Better side effects.
Topical steroids can cause skin to thin and atrophy, cause discoloration, acne, adrenal suppression, and osteoporosis.
55
Pimecrolimus cream (EIDEL) and Tacrolimus (PROTOPIC) ointment are examples of?
Topical immunomodulators
56
What is another use for Tacrolimus ointment?
PO version can help prevent organ rejection in transplant patients; it decreases transcription of inflammatory mediators.
57
What TIMs can cause lymphoma if taken orally, but is not known to cause it in topical form?
Tacrolimus, PO version was black-boxed for causing T cell lymphoma.
58
Tacrolimus - potency?
Medium
59
Pimecrolimus - potency?
Low
60
ADR TIMs?
Skin burning and warmth in 25-50% of patients. Must avoid sun exposure and use sunscreen.
61
CI TIMs?
| Why are they used?
Not good for those with weak immune systemics.
This is a first line steroid sparking agent for atopic dermatitis BID in patients who can't tolerate topical steroids.
62
Your patient is unable to tolerate topical corticosteroids, you choose to place him on topical immunomodulators. Is this the correct course of action?
Yes, as they are considered a first line steroid sparing agent for atopic dermatitis.
63
25-50% of patients using TIMs experience, what?
Skin burning and warmth
64
Your pt has a localized contact dermatitis reaction. What should be your initial go to class of medications?
Topical Hydrocortisone
65
Your patients dermatitis presents with weeping lesions. What vehicle type would you prescribe?
What would you want to avoid?
Prescribe a gel.
Avoid an ointment.
66
What type of conditions require systemic corticosteroid treatment via the PO route?
Widespread, progressive, and chronic.
67
What type of agent is used to dry mucous secretions, shrink cells, and cause blanching?
Astringents
68
Name two types of astringents.
Calamine lotion
| Zinc oxide
69
The culture of your pt’s itchy lesions come back positive for MRSA.
Your pt also had an organ transplant 3 years ago. You decide to treat with Clindamycin and a medium potency topical corticosteroid. Is your treatment correct?
Clindamycin- YES
| Steroid- NO due to immunosuppression
70
Your patient's nasal culture comes back for MRSA, what is your drug of choice?
Bactroban.
71
What systemic antibiotics should be used for 7 days for a more involved impetigo disease?
Dicloxacillin
| Cephalexin
72
What are the two main causes of impetigo?
Staph and strep
73
What is the MOA for Bactroban?
Binds bacterial tRNA, preventing protein synthesis.
74
How does Alatbax's MOA treat MRSA?
Inhibits the ribosome
75
What medication is used for impetigo is a potential skin irritant and has possible decreased the penetration?
Altabax
76
What is important about the differential Dx for impetigo?
Ensure that its not facial contact dermatitis.
77
When would you use topical corticosteroidsin impetigo?
Never, there is no place for it in the treatment.
78
What is a fatty lubricant secreted by the skin and what condition will it cause?
Sebum
| Acne
79
How do abnormal keratinization and increased sebum cause acne?
Synergistically, plus the sebaceous follicle.
80
What is the name of the gram positive organism that colonizes the hair follicle?
Propionbacterium Acne (Acne Bacillus)
81
What are the four cases of acne?
Increased sebum production, increased keratinization, Bacterial colonization,
Immune mediated inflammatory response.
82
Your pt is highly sexually active, eats lots of fast food, only believes in showering 3 times a week cuz she's a filthy hippie and deals with a large amount of psychological stress because her fragile liberal mind needs safe spaces. What would you tell her about how those conditions contribute to her acne?
None of those things contribute to her acne.
83
Your pt feels that steroids will finally give him the muscles that all the ladies want despite the fact he cant chew gum and walk at the same time. How would this impact his acne?
Androgens will activate and worsen acne.
84
Explain how physiologic stress impacts acne?
Increased stress will increase glucocorticoid secretion, worsening acne.
85
During what seasons will acne worsen and improve?
Worsen in winter, improve in summer
86
Explain the five pathogenic steps of acne formation.
Pooling of sebum creates anaerobic conditions allowing P.Acne to increase
T-cells respond to this by causing inflammation
The lipase secreted from the bacteria hydrolyze triglycerides into fatty acids
This increases keratinization and comedome formation
Cytokine and chemokines production generates pus
87
Give an example of non-inflammatory acne lesion.
open and closed comedomes
88
Give an example of an inflammatory acne lesion.
Papulopustular or nodular lesions.
89
What is the curative treatment for acne?
There isn't one, only treatment is to reduce severity.
90
It has only been one week since you started your patient on acne medication. She is upset because prom is two weeks away and there hasn't been much improvement. What do you tell her?
Treatment takes time and she has to allow 1-2months of treatment before modification or seeing results.
91
Name six goals of acne treatment.
Realizing this is chronic and requires early, aggressive and maintenance therapy
Reduce the # and severity of lesions
Slow progression of signs and symptoms
Limit duration
Prevent long term disfigurement
Avoid psychological suffering
92
Your patient has been on systemic corticosteroid tx for about 7 weeks now. She develops pustular inflammation of the trunk. What condition does she have?
Drug induced acne
93
Name three other types of medications that lead to drug induced acne.
Anti-epileptics
Tuberculosis
Lithium
94
What is a critical target for the treatment of acne?
The microcomedome to eliminate follicular occlusion in order to arrest the pathologic cascade.
95
What pathogenic steps of acne do you want to target?
All of them.
96
What drug is effective at treating all the pathologic steps of acne?
Retinoids
97
What medications are effective at normalizing follicular keratinization
Retinoids
Azelaic acid
Benzoyl peroxide
98
What medications are effective at decreasing sebum production?
Retinoids
Isotretan
Hormone modulation
99
What medications are effective at suppressing bacteria?
```
Antibiotics
Retinoids
Benzoyl peroxide
Azelaic acid
Isotretan
```
100
What meds are effective at preventing the inflammatory response?
Antibiotics
| Retinoids
101
How do surfactant systems work in acne treatment?
Remove fats and oils from skin.
102
What is important to remember about topical therapies?
They only work where applied. Most cause skin irritation which leads to patient discontinuation.
103
Your patient presents iwth acne caused by P. acnes proliferation. What is your course of treatment?
First, benzoyl peroxide. Then, topical and oral antibiotics. Lastly, isotretinoin.
104
Your patient presents with an inflammatory response of acne. What are your treatment options?
Intralesional corticosteroids
Oral corticosteroids
Topical and oral antibiotics
105
Your patient presents with abnormal serum production. What are your treatment options?
```
Anti-androgens
Isotretinoin
Topical and oral abx
Corticosteroids
Estrogens
```
106
Your patient presents with an abnormal characterization of the follicle. What are your treatment options?
Salicylic acid
Benzoyl peroxide
Topical retinoids
Isotretinoin
107
What is the MOA for Benzoyl peroxide?
Penetrate the stratum corneum and is then converted to benzoic acid, which has activity against P. acnes.
108
What is the dosing protocol for benzoyl peroxide?
Start at a low concentration of 2.5% once daily and hten increase strength/freq as tolerated.
109
Benzoyl peroxide will often be found in combination with what?
Antibiotics, such as erythromycin or clindamycin.
110
What are some adverse reactions to benzoyl peroxide?
Bleaching of hair and clothes
| skin and mucous membrane irritation.
111
What is thought to be the mechanism of action for Azelaic acid?
It is thought to inhibit the conversion of testosterone to dihydrogen testosterone.
112
What is an absolute contraindication to vitamin A usage and why?
Pregnant women; can lead to severe teratogenicity and don't want to mess with vitamin A and derivates during pregnancy.
113
What is the acid form of vitamin A?
Retinoic acid (Tretinoin)
114
What is thought to be the mechanism of action for retinoic acid?
Correct abnormal follicular characterization.
Reduces P. acnes colonies.
Reduces inflammation.
115
Your patient presents with non-inflammatory comedomal acne. What is your first line therapy?
Tretinoin
116
You explain to your patient that tretinoin is photolabile. Your patient looks at you with a blank look bc you just used a big word. First, you go over the defintion in your head, wahat does it mean? How do you explain it?
Photolabile - something susceptible to chemical change during the exposure to radiant light energy, such as UV rays.
You explain it becomes unstable in sunlight and will cause severe sunburn so she needs to use high SPF sunscreen.
117
Your patient is using both benzoyl peroxide and tretinoin for their acne. Your patient feelslike their condition is not impvoing. What is an important question to ask them about the use of their medication?
Have they ensured that they have removed all the benzoyl peroxide from the area prior to tretinoin application. Benzoyl peroxide will ianctivate tretinoin.
118
What topical retinoid is stable in sunlight and with benzoyl peroxide?
Adapalene (Differin)
119
This medication is a third generation retinoid used for acne and psoriasis and is sometimes combined with topical steroids to reduce skin irritation?
Tazarotene (Tazorac)
120
Topical retinoid treats Kaposi's sarcoma?
Alitretonin (Panretin)
121
This topical retinoid is used for T-cell lymphoma
Bexarotene (Targretine)
