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
