Week 7 derm

Question 1

What is hidradenitis?

Answer 1

Nodulocystic “acne” of the apocrine glands. (axillary and groin region)

Occlusion of the follicular ostia in apocrine glands causes inflammation, and sometimes a secondary infection. The inflamed gland ruptures into the dermis with abscess formation.

Question 2

Clobetasol

Group? Strength? Use on?

Answer 2

Group 1
Superpotent
hand/foot dermatitis

Question 3

Fluocinonide

Group? Strength? Use on?

Answer 3

Group 2
Potent
hand/foot, body dermatitis

Question 4

Triamcinolone

Group? Strength? Use on?

Answer 4

Group 4
Mid strength
large area on body

Question 5

Desonide

Group? Strength? Use on?

Answer 5

Group 6
Mild
Face, groin

Question 6

Hydrocortisone

Group? Strength? Use on?

Answer 6

Group 7
least potent
face, groin

Question 7

How does UVA affect the skin? Melanocytes?

Answer 7

• UVA can reach the dermis
• Biphasic as it causes immediate erythema then reappears 12 hours later
• It causes immediate photo-oxidation

Question 8

How does UVB affect the skin? melanocytes?

Answer 8

• UVB can only reach the epidermis
• Erythema peaks after 24 hours and lasts days
• stimulates proliferation and synthesis of new melanin

Question 9

Describe the synthesis of vitamin D

Answer 9

1) cholesterol
2) 7-dehydrocholesterol + light
3) calciferol –> isomerization
4) Vitamin D

Question 10

Basal cell carcinoma characteristics? common mutation?

Answer 10

• most common skin cancer
• pearly appearance with telangiectasia
• PTCH tumor suppression gene

Question 11

Squamous cell carcinoma characteristics?

Answer 11

• second common skin cancer
• actinic keratosis lesion (scaly)
• P53 mutation

Question 12

Melanoma characteristics?

Answer 12

• lest common skin cancer
• typically dark appearance
• CDK2A (INK4A) gene that encodes fro p16 and p14ARF

Question 13

Dermal melanocytosis (Mongolian spot)

Answer 13

• hyperpigmentation, usually in the lumbosacral area

- failure of melanocyte to migrate

Question 14

Piebaldism

Answer 14

• autosomal dominant mutation in the C-Kit gene that prevents proliferation and migration of melanocytes causing patches of hypopigmentation of the skin and hair

Question 15

Oculocutaneous Albinism

What are causes for type I and type II?

Answer 15

• autosomal recessive condition that prevents proper synthesis of melanin resulting in lack of pigment in hair, skin and eyes
• Type I
  
  • defective tyrosinase
• Type II
  
  • defective TRP-1/P-protein

Question 16

Phenylketouria

Answer 16

• autosomal recessive disease affecting phenylalanine hydroxylase. This prevents the synthesis of tyrosine and results in pigment dilution, mental deficiency, and seizures

Question 17

Griscelli syndrome

Answer 17

autosomal recessive mutation in the RAB27a genes that result in the inability to transfer melanosomes to keratinocytes resulting in diffuse hypopigmentation and silvery hair

Question 18

Post-inflammatory hyperpigmentation (PIH)

Answer 18

• Occurs after inflammation of the skin (acne, burns)

- “fumbling” of melanosomes results in dermal melanophages ingesting the melanin

Question 19

Panhypopituitarism

Answer 19

Decreased production of MSH and ACTH resutling in a chalky white appearance

Question 20

Adrenal insufficiency (addison’s disease)

Answer 20

Failure of the adrenal gland to respond to ACTH, which in turn causes more secretion of MSH and ACTH making the patient bronzed

Question 21

Melasma

Answer 21

stimulation of increased melanin synthesis due to increased levels of estrogen and progesterone

Question 22

vitiligo

Answer 22

Autoimmune destruction of melanocytes resulting in patches of hypopigmentation

Question 23

Argyria

Answer 23

long term ingestion of colloid silver salts turning the skin slate-gray pigmentation

Question 24

minocycline

Answer 24

Tetracycline antibiotic use causes minocycline deposition in the skin, shins, scars, thyroid, bones, teeth, sclera resulting in a black-blue discoloration

Question 25

Hermansky-Pudlack Syndrome

Answer 25

Autosomal recessive mutation of HPS genes resulting in pigment dilution and bleeding

Question 26

Waardenburg Syndrome

Answer 26

Mutations in Pax3, MITF, Sox10:
control melanoblast proliferation and migration
leading to Heterochromic irides, white forelock, deafness

Question 27

Describe the synthesis of melanins (eumelanin and pheomalanin)

Answer 27

tyrosine
Dopa
Dopaquinone
Dopachrome (-> Eumalanin) + CysteinylDOPA (-> Pheomelanin)