alopecia areata
Mention at least 4 underlying factors and triggers
1. Genetic susceptibility, 20% had a first-degree relative, HLA-DQB1*03 allele (80%), HLADR4 (totalis and universalis)
2. Immune dysfunction:loss of folliculat immune priviledge, trigger a T cell attach that halt normal hair production
3. Emotional distress
4. Infection and illnesss
5. Associated conditions: thyroid disease, vitiligo, eczema
Mention the 2 most common dermatophytes that cause tinea capitis in Canada and America?
1. T. tonsurans
2. M audouinni 3. M. canis
In Europe: M. canis and T. violaceum
In Africa: T violaceum and T schoenleinii
What is the cause of trichotillomania?
Hair pulling disorder is considered.
What is the mechanism of action of traction alopecia and common causes in pediatrics?
Results from mechanical stress on hair follicles, leading to follicular damage and hair loss.
Common causes in pediatric patients include tight ponytails, braids, cornrows, buns, chignons, hair extensions, and the use of beads or barrettes that increase tension on the hair shaft
More in chemically relaxed or thermally straightened hair
Trichoscopy shows features of multiple beaded hair with regularly placed nodes and internodes
Monilethrix
Acquired: Alopecia areata with pohl pinkus constrictions, chemotherapy induced alopecia, from hair styling
Congenital: Monilethrix-like congenital hypotrichosis
Peak incidence
Peak incidence: 15-30 years of age
The onset occurs before the age of 20 in ~50%
What are the 3 types of in vivo hair invasion caused by dermatophytes?
1. Ectothrix: exterior of the hair shaft, do fluorecense - M canis, M gypseum, T verrucosum
2. Endothrix: whitin the hair shaft, cuticle remains intact, do not fluoresce - T tonsurans, T violaceum
3. Favus: favus like crusts or scutula - T schoenleinii
Clinical criteria for diagnosis of trichotillomania:
Recurrently removing hair, resulting in hair loss (which may be hidden)
Making repeated attempts to decrease or stop the hair pulling
Experiencing significant distress and/or impairment in functioning from the activity
Epidemiology of traction alopecia
Hair shaft fragility that occurs on weakened points, nodes, along the hair shaft leaving "brush like ends"
Trichorrexis nodosa
Acquired: trauma, heat, nutritional deficiencies, Biotin, Vitamin A, and Zinc deficiency, hypothyroidism
Congenital: Ectodermal dysplasias, trichothiodystrophy, Menkes, Netherton, Bazex–Dupre×–Christol syndrome
Types of alopecia areata
1. Patchy
2. Ophiasis
3. Diffuse
4. Totalis
5. Universalis
Age-related and demographics of tinea capitis, mention 2 facts
Most common in children 5-10 years of age
Most common in black male children
Estimated prevalance of trichotillomania
The estimated prevalence of TTM is between 0.5 and 3% of the population.
Onset is typically between late childhood and early adolescence, with the condition often persisting into adulthood
Clinical features of early tricotillomania?
Early TA is reversible: perifollicular erythema, scaling, itching, or pain at the hairline or areas under tension
Peripilar casts—small keratin cylinders around hair shafts—may also be observed.
Also called bamboo hair, occurs by invagination of the distal hair shaft into the proximal hair shaft creating a ball in a cup appearance
Trichorrhexis invaginata
Netherton syndrome triad: ichthyosis linearis circumflexa, atopic diathesis, and trichorrhexis invaginata
What are the dermoscopic findings in alopecia areata?
1. Yellow dots (empty hair follicle openings filled with sebum or keratin)
2. Black dots (remnats of fractured hair shafts broken at the scalp level)
3. Excalmation marks hairs (short hairs that taper distally, meaning they are narrower near the scalp
4. Short vellus hair (thin, short and often lighter colored regrowing hairs)
What are the clinical types of tinea capitis?
Non inflammatory: gray patch, black dot and diffuse scaling
Inflammatory: kerion and favus
Clinical features and at least 3 dermoscopic findings
Birzarre or irregularly-shaped patches of alopecia.
Stubbly, with hairs of varying lengths.
Children tend to pull on hairs that are easy to reach and are on the same side as their dominant hand, frontotemporal areas (areas behind the forehead and ears) and the vertex (top of the head).
Eyelashes and eyebrows may also be broken or absent.
Scratches, bruises and erythema from picking may also be seen.
Repeated removal of hair damages the follicles and may lead to irreversible scarring
Trichoscopy:
-Broken hairs at different levels (100%)
-Short villous hairs (90%)
-Black dots (85%)
-Trichoptilosis or split ends (70%) -specific
- V hairs (60%) - specific
- Coiled hairs (40%)
-Follicular hemorrhages (40%)
-Concentric hair (40%)-specific
-Tulip hair (25%) specific
Clinical features of late or chronic traction alopecia
Chronic traction can lead to folliculitis, pustules, scarring, and permanent hair loss with scarring.
The pattern of hair loss often corresponds to the hairstyle, with marginal alopecia affecting the frontal and temporal hairline and nonmarginal alopecia occurring elsewhere on the scalp
“tiger tail banding” (alternating bright and dark bands on polarized microscopy) due to cystein defiency
Trichothyodystrophy
Isolated or associated with intelectual impairment, with or withou photosensitivity.
What JAK inhibitor is approved for pediatric alopecia areata, type of JAK, age cutoff, side effects and dosage?
1. For severe alopecia areata the only JAK inhibitor approved in children 12 years and older is RITLECITINIB.
2. Mechanism of action: JAK-3
3. SE: headache, diarrhea, acne immunosuppression, increase in CK
4. 50mg PO daily
Best treatment option for tinea capitis in Canada, dosage and duration?
Terbinafine 6 weeks, longer (12 weeks for Microsporum spp)
<20kg: 67.5mg/day
20-40kg: 125mg/day
>40kg: 250mg/day
Apart from psychotherapy, mention at least 3 medications to treat trichotillomania
1. N acetyl cistein 1200–2400 mg/day.
2. Olanzepine
3. Clomipramina
4. SSRI
Apart for modifiying hair styling practices, what medications can be used to treat traction alopecia, mention at least 3.
1. TCS
2. Topical Minoxidil
3. Topical antibiotics
3. Oral antibiotics (doxycycline)
What hair shaft disorder is characterized by tightly curled, short, and kinked hair that on trichoscopy shows “crawling snake” appearance, and mention at least 3 associations?
Wooly hair
Associations: cardiomyopathy, congenital ichthyosis, keratosis pilaris, Noonan syndrome, cardiofaciocutaneous syndrome, nail dystrophy, osteoma cutis, and severe neurologic disorders