Baldness Flashcards
Describe embryology of hair
Ectoderm -> hair shaft and pilosebaceous follicle
Medoserm - deral papillae
Describe the anatomy of hair
Hair shaft and root
- SHAFT: 3 layers of keratinized cells
- ROOT: = follicle = contains matrix (rapidly proliferating cells) and zone of keritinization (production of shaft)
Describe hair growth
3 phases:ACT
- ANAGEN - Proliferative phase (2-5yrs)
- 90% of follicles, longer phase in W
- CATAGEN - Degradation phase (2-3wks)
- 2% of follicles, bulb atrophies and separates from papilla ->club
- TELOGEN - Resting phase (3mths)
- 8% of follicles, hair sheds as attachment to papila weakens
Describe types of hair
- Lanugo - fetal hair, unpigmented, shed prior to birth
- Vellus - infant hair, hypopigmented, replaces lanugo hair in post-natal period
- Terminal - coarse thick hair, pigmented. May be replaced by vellus hair if follicle abnormal
DDX of alopecia
CONGENITAL
- Cutis aplasia
- Ectodermal dysplasia
ACQUIRED
- Androgenic Alopecia
- Alopecia Areata (autoimmune)
- Discoid Lupus erythematous
- Lichen planopilaris
- Endocrine (hypothyroid, low iron, menopause)
- cicatricial
- traumatic
- Meds (chemo, steroids)
Define Androgenic Alopecia
Gradual conversion of terminal hair to villus hair,
What factors contribute to androgenic alopecia
- Genetics: inheritance of AD sex-linked gene
- Androgen sensitivity: high alpha 5 reductase activity converting testosterone into DHT
- Age: anagen phase shortend with each cycle
How do you classify Male Pattern Baldness
NORWOOD
Type 1 - no frontotemporal recsession
Type 2 - frontotemporla recession posteriorly but not >2cm anterior to coronal plane by EAC
Type 3 - frnototemporal recsession posteriorly and <2cm anterior to coronal plane by EAC
Type 3 (vertex) - hair loss at vertex
TYpe 4 - both frontotemporal and vertex hair lone iwth wide band of hair separating two areas of hair loss
Type 5 - narrower band of hair compared to type 4
Type 6 - interconnected tow areas of baldness
Type 7 - sparse hair on sides/back
How do you classify female pattern badness
Ludwig
Defined by vertex hair
1- mild diffuse loss
2- moderate
3- severe
WHat are management options for baldness
Non-operative
- Camouflage
- Medications
Operative
- Hair transplantation
- Alopecia reduction with scalp excision
What is Minoxedil and how is it used
Minoxedil = Rogaine, 2-3% applied BID, topical
MAC: possible direct stimulation of hair follcile, vasodilation (noted to cause hypertrichosis in treatment of HTN
Indications: vellus hair, not complete alopecia, <40
ADverse effect: dermatitis
Conrtaindications: CVD
What is finasteride and how is it used
5 alpha reductase inhibitor, 1mg po daily
MAC- reduces conversion of testosterone to DHT, reverses hair miniturization (covnersion of terminal to vellus)
6-12mths to note effect, best in young men
ADverse: decreases libido, rapidly progresses baldness if stopped
Teratogen****
Describe the indications for hair transplantation
primary alopecia
traumatic alopecia
reconstruction of eyebrows
What is the ideal hairline
8-9cm from the horizontla line drawn at the suprabrow
What are the graft types for hair transplantation
- Micrograft: 1-2 hairs
- Minigraft: 3-8 hairs
- Follicular unit graft: contains 3-4terminal hairs, a sebaceous gland, arrector pilli
- round graft
Describe the steps of Follicular Unit Transplantation (traditional technique)
- Pre-op: chlrohex prep, donor hair trimmed, new hairline marked 8-9cm above suprabrow
- Analgesia: LA and sedative
- Donor site: Occipital area + superiorly to parietal zone and anteriorly up to tragal perpendicular
- Graft harvest
- Strip technique: 8mmx18cm = 1000-2000FU with tricophytic techqnieue (angled blade)
- Graft preparation
- Cut into mm segments
- Subdivide into micro or minigrafts
- Recipient - infiltrte tumescence
- Transplant -
- 20-30FU per cm2= 40-60 hairs/cm2
- may repeat in 4-6mths
- Post-op
- minoxidil 2-3% BID
- hair enters telogen phase for 3mths then anagen for new growth at 4mth
Describe diffrence between follicular unit transplantation and follicular unit Extraction
Graft harvested is not as strip but as FU with small punch excisions
Disadv: can have moth eaten look as punch trasnsects
largeer donor area required
Adv: donor heals by 2’ intention w less scarring
Complications of hair transplantation
Inclusion cysts, ingrown hair
Poor scarring
elevated/depressed grafts
abnormal hairline
telogen effluvium (expectoration of degradated hair)
Describe techqnieu for alopecia reduction with excision of scalp
- Tissue expansion intraop with excision
- Scalp extension with silinone elastomer and anchor hooks
- Flaps :
- Juri temoporoparieto-occipital
- Elliott scalp flap (lateral flap)
