pharmacology: dermatology

the pharm lecture on some of the conventional drugs used to treat dermatologic conditions. there are a number of topical antimicrobials used to treat superficial skin infections; the most common might be neosporin, which is most effective against superficial bacterial infections, although has the potential to be ototoxic. muciprocin is used for impetigo as well as part of the treatment against MRSA-- in this treatment it is prophylactically applied to the nares to eradicate potential nasal infection from MRSA. ketoconazol is an antifungal that works by inhibiting sterol synthesis. glucocorticoids can be applied topically in cases of inflammation such as dermatitis, psoriasis, eczema, urticaria. application to the face should be avoided if possible, in particular because abruptly stopping could cause rosacea and perioral dermatitis.

treatment of acne involves drugs that reduce the hyperkeratinization and sebum production, as well as combat the propionobacterium that is associated with acne inflammation. vitamin A derivatives such as isoretinoin are particularly effective, although potentially teratogenic. finally, PUVA is a treatment used for psoriasis and stands for psoralen plus UV-A light-- psoralen is a compound that reacts with ultraviolet light. phototherapy is one step in the progression of the treatment of psoriasis, which also involves corticosteroids, vitamin D3, and TNF inhibitors.

questions
neosporin...
1. effective against MRSA or cellulitis?
2. what is neosporin?
3. indications for neosporin?
4. mechanism of action?
5. neosporin is also sometimes used with...
6. avoid use of...

muciprocin / bactroban...
7. used for...
8. effective against which microorganisms?
9. mechanism?
10. special instructions when treating MRSA?

ketoconazol / nizarol...
11. class?
12. indication?
13. mechanism of action?
14. side effect?

topical glucocorticoids...
15. should be avoided on what type of skin and why?
16. indications?
17. local side effects?
18. when applied to the face, has potential for which side effects?
19. indications for intralesional injection?

retinoids and acne...
20. structure?
21. effect on skin?
22. indications?
23. drug treatment strategy for acne?

tretinoin / retin A...
24. indication?
25. mechanism of action?
26. side effects?

isoretinoin / accutane...
27. indications?
28. mechanism of action?
29. recurrence of acne when drug is stopped?
30. contraindicated in...
31. measures taken to prevent negative effects from [30]?
32. potential GI side effect?

psoriasis...
33. immune system involvement in production of psoriatic skin lesions?
34. treatment of psoriasis involves stepwise progression of...
35. describe the phototherapy protocol.
36. what is PUVA?
37. other indications for PUVA?
38. side effects?

answers
1. no.
2. polymyxin B plus neomycin.
3. superficial bacterial skin infections. eyes and ear infection.
4. polymyxin disrupts bacterial cell membrane, bacitracin interferes with PDG's of cell wall.
5. corticosteroids.
6. otic solution, because of potential ototoxicity of neomycin.

7. impetigo, other bacterial skin infections.
8. bacteria, not viruses or fungi.
9. inhibits bacterial protein synthesis.
10. apply to the nasal nares as well as the infection site to eradicate potential nasal infection.

11. anti-fungal.
12. superficial fungal infection.
13. inhibits sterol synthesis.
14. skin irritation.

15. abraded unless with antimicrobials because of greater systemic absorption.
16. dermatitis, eczema, psoriasis,
17. skin atrophy
striae
telangiectasias
purpura
acneiform lesions
perioral dermatitis
18. rosacea and perioral dermatitis when stopped abruptly.
19. cystic acne
psoriasis
discoid lupus

20. vitamin A derivatives.
21. cellular proliferation and differentiation
immune function
inflammation
sebum production
22. SCC
actinic keratosis
cystic acne
23. salicylic acid, benzoyl peroxide, antibiotics, retinoids.

24. acne or photo damaged skin.
25. reduction of hyperkeratinization, thickening of epidermis, dermal collagen synthesis.
26. erythema
peeling
burning / stinging
photosensitivity

27. acne / acne rosacea, hidradenitis suppurativa
28. reduction of hyperkeratization, reduction of sebum production, reduction of propionobacterium acne.
29. 40% of patients within 6 months.
30. pregnancy.
31. two forms of birth control required for females of child bearing age on this medication.
32. ulcerative colitis.

33. immune cells move from the dermis to the epidermis, where they stimulate keratinization.
34. corticosteroids
vitamin D3
phototherapy
systemic therapy
TNF inhibitors
35. use ultraviolet A or B light source along with a psoralen drug such as methoxsalen
36. psoralen plus ultraviolet A.
37. vitiligo
T cell lymphomas
alopecia areata
urticaria pigmentosa
38. nausea, erythema, blistering
skin cancer, actinic keratosis.

CPD I: dermatology lecture I

This was the first lecture of second year, from the major class of this year: clinical physical diagnosis (CPD). We dove into dermatology and the diagnosis of different skin lesions. First we talked about different factors to consider when diagnosing a lesion, such as appearance, time factors, spreading, sensation, change, previous treatment. In general the questions of diagnosis seem to fall under the categories: What is it? How did it develop? What's been done to treat it? What are other internal or hereditary factors to consider? What are some external or environmental factors to consider? What do the other organ systems in the body indicate?

Then we talked about the actual classification of different skin lesions. "Primary morphology" refers to the particular type of skin lesions, such as a bullae, papule, macule, scaling, erosion, etc. "Secondary morphology" refers to the overall shape / distribution of the lesions, such as linear, annular, nummular, serpiginous. Other factors used to distinguish between lesions are: color, texture, location, clinical manifestations. Here are examples of what different colors indicate:

Red: erythema
Orange: hypercarotenemia
Yellow: jaundice
Green: pseudomonas
Violet: port wine stain
Grey/Blue: anemia
Black: melanocyte pathology or arterial insufficiency.

Some other terms to know:

Nummular: circular lesions with lighter center
Verrucous: Irregular texture
Lichenification: thickened texture
Induration: deeper lichenification

A number of tests are available to distinguish between these lesions, such as biopsies, KOH test (for yeast, fungus), wood's lamp (UV light which detects certain fungal infections), diascopy (glass slide test for blanching), immunoflourescence test, ESR, ANA tests.

We started looking at Acne Vulgaris and Rosacea, two common skin pathologies. Acne vulgaris is commonly caused by androgen hormones or bacterial interaction with the skin, which leads to the obstruction of the pilosebaceous unit, which leads to different lesions such as comedones, nodules, papules, cysts, pustules, and purulent sacs. It can have similar manifestations to perioral dermatitis, drug eruptions, and rosacea.

Rosacea, on the other hand, is a different pathology which can start with flushing of the skin, and can progress to telangectasia (tortuous vessels), papules/pustules, and at its worst, rhinophyma (excess collagen deposition and hyperplasia of sebaceous glands). The differential diagnosis for rosacea: SLE, discoid lupus, acne, drug eruptions, perioral dermatitis.