Week 7 derm Flashcards
(27 cards)
What is hidradenitis?
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.
Clobetasol
Group? Strength? Use on?
Group 1
Superpotent
hand/foot dermatitis
Fluocinonide
Group? Strength? Use on?
Group 2
Potent
hand/foot, body dermatitis
Triamcinolone
Group? Strength? Use on?
Group 4
Mid strength
large area on body
Desonide
Group? Strength? Use on?
Group 6
Mild
Face, groin
Hydrocortisone
Group? Strength? Use on?
Group 7
least potent
face, groin
How does UVA affect the skin? Melanocytes?
- UVA can reach the dermis
- Biphasic as it causes immediate erythema then reappears 12 hours later
- It causes immediate photo-oxidation
How does UVB affect the skin? melanocytes?
- UVB can only reach the epidermis
- Erythema peaks after 24 hours and lasts days
- stimulates proliferation and synthesis of new melanin
Describe the synthesis of vitamin D
1) cholesterol
2) 7-dehydrocholesterol + light
3) calciferol –> isomerization
4) Vitamin D
Basal cell carcinoma characteristics? common mutation?
- most common skin cancer
- pearly appearance with telangiectasia
- PTCH tumor suppression gene
Squamous cell carcinoma characteristics?
- second common skin cancer
- actinic keratosis lesion (scaly)
- P53 mutation
Melanoma characteristics?
- lest common skin cancer
- typically dark appearance
- CDK2A (INK4A) gene that encodes fro p16 and p14ARF
Dermal melanocytosis (Mongolian spot)
- hyperpigmentation, usually in the lumbosacral area
- failure of melanocyte to migrate
Piebaldism
- autosomal dominant mutation in the C-Kit gene that prevents proliferation and migration of melanocytes causing patches of hypopigmentation of the skin and hair
Oculocutaneous Albinism
What are causes for type I and type II?
- 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
Phenylketouria
- autosomal recessive disease affecting phenylalanine hydroxylase. This prevents the synthesis of tyrosine and results in pigment dilution, mental deficiency, and seizures
Griscelli syndrome
autosomal recessive mutation in the RAB27a genes that result in the inability to transfer melanosomes to keratinocytes resulting in diffuse hypopigmentation and silvery hair
Post-inflammatory hyperpigmentation (PIH)
- Occurs after inflammation of the skin (acne, burns)
- “fumbling” of melanosomes results in dermal melanophages ingesting the melanin
Panhypopituitarism
Decreased production of MSH and ACTH resutling in a chalky white appearance
Adrenal insufficiency (addison’s disease)
Failure of the adrenal gland to respond to ACTH, which in turn causes more secretion of MSH and ACTH making the patient bronzed
Melasma
stimulation of increased melanin synthesis due to increased levels of estrogen and progesterone
vitiligo
Autoimmune destruction of melanocytes resulting in patches of hypopigmentation
Argyria
long term ingestion of colloid silver salts turning the skin slate-gray pigmentation
minocycline
Tetracycline antibiotic use causes minocycline deposition in the skin, shins, scars, thyroid, bones, teeth, sclera resulting in a black-blue discoloration
