L-14 Hair Loss

• Hair loss and disorders of the hair and scalp are the topic of these study notes, presented by Jerome Obed, DO, FAOCD of Broward Dermatology & Cosmetic Specialists

Objectives

• Describe the basic hair growth cycles.
• Describe the types of hair loss.
• Describe how to take an adequate history and physical examination on a patient with hair loss or hair diseases.
• Identify diagnostic clues to hair loss and/or hair diseases.
• Describe the etiologies of hair loss and hair diseases.
• Describe the present therapies of hair loss and hair diseases.

Types of Hair

• Lanugo is the earliest type of hair.
• Vellus hairs are non-pigmented body hair.
• Terminal hairs are pigmented and the most mature hair type.

Hair Follicle Type and Shape

• Vellus hairs are <0.03 mm in size.
• Intermediate hairs are 0.03-0.06 mm in size.
• Terminal hairs are >0.06 mm in size.
• Circular hair shafts produce straight hair.
• Elliptical hair shafts produce wavy hair.
• Flat hair shafts produce curly hair.

Basic Data on Hair Follicles

• There are 5 million total hair follicles; most are vellus.
• The scalp has approximately 100,000 follicles in brown or black haired individuals.
• Blondes have 10% more hair follicles.
• Red heads have 10% fewer hair follicles.
• Hair grows 0.4mm per day.
• Cutting or shaving does not influence hair growth.
• Androgens increase hair growth size and rate in dependent areas, like the beard.
• Estrogens reduce hair growth rate.

Hair Embryology & Morphogenesis

• First follicles form at 9 weeks on eyebrows, upper lip, and chin.
• Most other follicles follow suit in 4-5 months.
• No new follicles are formed in adulthood.
• The hair follicle is part of the pilosebaceous unit and gives rise to the hair shaft.
• The bulb is the lowest part of the follicle and contains the matrix, responsible for growth and differentiation.
• Cells in the matrix give rise to the hair shaft, specifically the cuticle, cortex, and medulla.

Hair Anatomy

• Hair shaft structures: medulla, cortex, cuticle.
• Inner root sheath structures: cuticle, Huxley's layer, Henle's layer.
• Outer Root Sheath
• Glassy Membrane
• The outer root sheath is continuous with the overlying epidermis.
• Bulge: the region of insertion of the arrector pili muscle to the hair follicle.
• The critical line of Auber is the widest diameter of the bulb and has the highest mitotic activity.

Hair Pigmentation

• Hair color is determined by melanocytes in the matrix.
• Hair is only colored when growing.
• Eumelanin produces brown or black hairs.
• Pheomelanin produces red or blonde hairs.
• Absence of pigment produces white hair.
• Marked loss of pigment produces grey hair.
• Red hair is due to a genetic defect in melanocortin-1.

Hair Growth Cycle

• Three main phases: anagen, catagen, telogen
• Anagen is the growth phase that lasts 2-6 years; 85-90% of hairs are in this phase.
• Catagen is the transition phase that lasts 2-3 weeks; less than 1% of hairs are in this phase.
• Telogen is the resting phase that lasts 3 months; 10-15% of hairs are in this phase.
• Approximately 85% of all hairs are in the growing phase, or anagen, at any one time.
• The anagen phase can vary from two to six years.
• Hair grows approximately 10cm per year, thus individual hairs are unlikely to grow more than one meter long.
• Individuals with very long hair have a prolonged Anagen phase
• Catagen lasts about one or two weeks.
• During the Catagen phase the hair follicle shrinks to about 1/6 of the normal length.
• The lower part of the hair follicle is destroyed and the dermal papilla breaks away.
• Telogen lasts about 3 months, and the hair does not grow but stays attached to the follicle while the dermal papilla stays in a resting phase.
• Approximately 10-15% of all hairs are in the telogen phase at any one time.

Evaluation of Hair Loss

• There are 3 categories for evaluation of hair loss: non-invasive methods, semi-invasive methods, and invasive methods.
• Non-Invasive methods: questionnaire, hair counts, wash test, 60-second counts, photographs, dermoscopy.
• Semi-Invasive methods: trichogram
• Invasive methods: scalp biopsy.
• Other evaluations: photography/dermoscopy, hair pluck test/trichogram
• For hair pluck test/trichogram, 60-80 hairs are grasped with a hemostat with rubber booties.
• Hair is plucked by twisting and lifting hair shafts rapidly in the direction of emergence.
• Hairs are cut 1cm above roots and placed on a slide for light microscopy exam.
• History questions for hair loss include:
  • When did you last shampoo?
  • Is the hair coming out by the root or breaking off?
  • Do you notice excess loss on comb/sink/pillow/drain?
  • Is your hair becoming thinner?
  • Has your barber/beautician or friends/family noticed thinning?
  • Do you have any totally bald spots?
  • How many hairs on average do you lose daily?
  • Do you color/bleach/straighten/blowdry your hair?
  • Is any family member bald or suffers from thin hair?
  • Are your menstrual periods regular?
  • Is your scalp itchy or flaky?
  • Recent surgery/pregnancy/delivery/ thyroid disorder/acne/atopy?
  • Do you take any Medications (Rx, OTC, and herbal supplements)?
  • Family Hx of Atopy, thyroid, diabetes, rheumatoid arthritis, lupus?

Types of Alopecia

• There are 2 Types of Alopecia: Non-scarring (Non-Cicatricial) and Scarring (Cicatricial).
• Scarring implies the follicular epithelium has been replaced by connective tissue.
• Permanent injury to the follicular stem cell region
• Primary Cicatricial Alopecia involves a condition causing direct inflammation to the hair follicles.
• Secondary Cicatricial Alopecia involves an external cause that does not directly affect the hair follicle or cause inflammation such as a burn, radiation, or malignancy.

Alopecia DDX

• Non-Scarring: - Alopecia Areata - Telogen Effluvium - Anagen Effluvium - Androgenic Alopecia - Male - Female - Trichotillosis - Syphilitic Alopecia - Alopecia mucinosa - Vascular/Nerve - Endocrine - Loose Anagen Syndrome - Temporal Triangular Alopecia - Pressure-Induced Alopecia
• Scarring: - Lymphoid - Lupus - Lichen PP - CCCA - Neutrophilic - Folliculitis decalvans - Dissecting cellulitis - Pseudopelade of Brocq - Traction alopecia - Sarcoid - Pressure - KP Atrophicans

Non-Scarring Alopecia

• Large percentage of hairs enter telogen phase simultaneously in Telogen Effluvium.
• Telogen Effluvium usually involves less than 25% hair loss.
• Hair loss begins 3 months after a precipitating event with Telogen Effluvium.
• Thinning of hair involves entire scalp but may also involve other areas of body (axilla, groin) with Telogen Effluvium.
• Shedding of each follicle is independent of surrounding follicles: hair density maintained

Telogen Effluvium

• Excessive shedding of club hairs → “my hair is falling out”
• Causes - premature conversion to telogen, such as:
  • Surgery
  • Parturition
  • Fever
  • Drugs
  • Dieting
  • Traction
• Hair pull test – 40 hairs no more than 8 should be club shaped
• Iron deficiency, thyroid disease, and some papulosquamous diseases accentuate this accelerated telogen efflux
• Causes of Telogen Effluvium include:
  • Shedding of the newborn (physiologic)
  • Postpartum (physiologic)
  • Post-febrile illness (very high fevers i.e. malaria)
  • Severe infection
  • Severe chronic illness (i.e. HIV, systemic lupus erythematosus)
  • Severe, prolonged psychological stress
  • Post-surgical (major surgical procedure)
  • Hypothyroidism and other endocrinopathies (i.e. hyperparathyroidism)
  • Crash diets, liquid protein diets, starvation, psychiatric disorders
  • Medications
• Medications implicated in Telogen Effluvium:
  • anti-coagulants – heparin, warfarin
  • anti-hypertensives – beta-blockers, ACE inhibitors
  • hormones – oral contraceptive pill (during/after/changing), hormone replacement therapy, androgens
  • anticonvulsants – valproic acid, carbamazepine, phenytoin
  • psychiatric medications – lithium, amitriptyline
  • others – cimetidine, retinoids, antithyroid drugs, statins, interferons, amphetamines, NSAIDs, bromocriptine, levodopa
• Telogen hairs have club shape.
• Hair pull/pluck test is abnormal if >20% telogen.
• Absence of inflammation, scarring, atrophy and erythema
• Has a Good Prognosis as spontaneous recovery is found in most patients after months to years.
• Anagen Effluvium is hair loss seen following the administration of chemotherapeutic drugs such as antimetabolites, alkylating agents and mitotic inhibitors.
• Seen within days to weeks of the stimulus with Anagen Effluvium.
• Entirely reversible with drug cessation Anagen hairs
• Abrupt cessation of mitotic activity in rapidly dividing hair matrix cells
  • hair shaft thins and then breaks at skin surface
• Loose anagen syndrome is related to a defect in the hair cuticle, which, instead of anchoring the hair, folds back readily.
• Common in blond girls who's hair were does not grow past a certain length and is easily plucked without pain
• A keratin mutation is suspected in the pathogenesis of this disorder
• Hairs often containes cuticle which, when folded back, gives the appearance of a ruffled sock with Loose anagen.
• Trichotillosis, also known as trichotillomania, involves habitual pulling and plucking of hairs, and is a compulsive disorder.
• May occur with trichophagia/bezoar
• Histology shows pigment casts, bizarre twisted follicles, and normal follicles surrounding
• Treatment – SSRI's, or Selective Serotonin Reuptake Inhibitors
• Syphilitic Alopecia is a rate, sexually acquired, chronic infection caused by Treponema pallidum.
• Presents as a moth eaten appearance
• Usually has other sequelae of secondary syphilis
• Confirm with RPR/VDRL
• Alopecia areata affects men and women of all races equally.
• Seen in 2% of the population (60% of the cases are children/young adults)
• Dx made via presence of exclamation point hairs with Alopecia areata.
• Usually concomitant nail findings include Regular shallow pits (proximal matrix) and trachonychia, onchyomadesis, or red lunulas as well.
• Pathogenesis associated with loss of immune privilege in Alopecia areata.
• Follicular melanocytes seem to be the target
• TH1 immune response, characterized by IL-2, INF, & TNF, occurs early and at the bulb, which normally has very low MHC expression
• In AA, this MHC expression becomes overabundant, signaling the immune system to destroy the hair follicle
• Most cases resolve over time with Alopecia areata.
• Treatments for more extensive cases include Intralesional steroids, Topical steroids, Minoxidil, Oral steroids, Light therapy (NBUVB, PUVA), Squaric acid dibutyl ester, Eximer laser (308nm), TNF alpha blockade
• Alopecia Areata Associations include Atopic dermatitis, Trisomy 21, Lichen planus, and Autoimmune diseases: such as Hypothyroidism, SLE, Diabetes mellitus, Myasthenia gravis, Vitiligo
• Androgenic Alopecia manifests as Male-patterned Androgenic Alopecia or Female-patterned Androgenic Alpecia.

Alopecia: Female Androgenic

• Christmas tree like pattern
• More diffuse then male pattern
• Linked to elevated levels of 5 alpha-reductase
• May have underlying endocrine cause
• Treatments include Minoxidil, Finasteride, Spironolactone or cyproterone, Surgical procedures and Prosthetic wigs/weaves

Alopecia: Male Androgenic

• Genetic basis
• Starts usually in 20-30's
• Gradual loss of hair usually at the vertex or the hairline
• The reduction of 5 alpha testosterone is paramount
  • Blockade of this action prevents alopecia (specifically the type 2 isoenzyme of 5-alpha reductase)
  • Individuals castrated (eunuchs) do not experience alopecia Progressive shortening of the anagen phase with Male Androgenic Alopecia.
  • Smaller hairs, thinner hairs
  • Eventual follicular miniaturization to vellus hairs
  • Higher proportion of telogen hairs
• 4mm punch biopsy preferred for sufficient longitudinal and cross sections
  • Miniaturization of follicle
  • Decreased number of follicles Treatments include:
  • Minoxidil, which promotes survival of dermal papillae cells, prolongs anagen phase, and causes enlargement of shaft diameter
  • Finasteride, which Blocks Type II 5a-reductase. Studies using 1mg daily showed that 90% of men report discontinued hair loss and 35-65% report regrowth. A recent long term trial showed an increase in hair diameter.
  • Surgical intervention Scalp reductions may be attempted.
  • Difficult to get good results
  • Multiple reductions necessary and scarring becomes evident
  • Hair transplants Traditional Strip method
  • NeoGraft micro-follicular relocation
• Alopecia totalis: Complete loss of head hair
• Alopecia universalis: Complete loss of all hair
• Ophiasis - loss along temporal and occipital scalp
• Sisaipho - loss of hair everywhere but areas above
• Discoid Lupus Erythematosus is also known as chronic cutaneous lupus.
• Usually occurs on the face, ears and scalp (50%)
• More common in adults and females
• Lymphocytic cell type is predominate in Discoid Lupus Erythematosus.
• Clinical Findings include Erythema, Epidermal atrophy, Dyspigmentation, Telangiectasia and Follicular plugging.
• Associated with Pruritus and Tenderness
• DLE-associated scarring alopecia features Diagnosis confirmed by histology revealing Interface dermatitis, basement membrane thickening, and follicular destruction. Central Centrifugal Cicatricial Alopecia (CCCA)
• Aka-"hot comb” alopecia, follicular degenertion syndrome, Spurling's disease
• Most often seen in African-American women, but is also the most common form of scarring alopecia in any population
• Mild disease: perifollicular scaling and papules.
• Severe disease: highly inflammatory with pustule formation, crusting, intense erythema, and bacterial superinfection (folliculitis decalvans)

CCA Central Centrifugal Cicatricial Alopecia

• All variants have Chronic, progressive disease with eventual spontaneous 'burn out'
• Disease centered on the crown or vertex
• Symmetric alopecia with greatest disease activity occurring in the peripheral zone
• Clinical or histological evidence of inflammation in the active peripheral zone
• Pathogenesis features include patients with a history of chemical hair products or hot comb treatments. One Theory is that there an anatomic hair abnormality that predisposes them to follicular damage and inflammation resulting in CССА.
• Treatment: oral tetracycline plus potent topical steroid to halt progression
• Folliculitis Decalvans is a Type of Cicatrical Central Centrifugal Alopecia.
• Crops of pustules – usually due to chronic staph infection
• Treat with tetracyclines
  • Anti neutrophil
  • Anti bacterial
  • Can use Rifampin/Clinda, on a 10 week regimen
• Dissecting cellulitis of the scalp has Association with acne congoblata, hidradenitis suppurativa, & pilonidal cysts (Follicular'occlusion tetrad)
• Begins as multiple scalp nodules that become boggy & form sinus tracts with discharge
• Early disease spares the follicles but eventually leads to hair loss.
• Treatment: intralesional steroids, antibiotics, I&D, isotretinoin
• Relapses common
• Traction alopecia is caused by prolonged tension on hair, affecting both genders & all races.
• This is a Biphasic process-initially alopecia is non-scarring and reversible but with years of tractions becomes scarring and permanent
• Cicatricial Alopecia treatment is difficult to achieve success or even stop the progression.
• Options include Intralesional steroids, Topical steroids, Antibiotics, Retinoids, Cyclosporine, TNF alpha inhibitors, Low dose LMW heparins (LPP), Antimalarials (DLE, Sarcoid) and Hair transplantation