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Toronto Notes 2019 Diseases of Hair Density
Other Cutaneous Cancers
CUTANEOUS T-CELL LYMPHOMA
Clinical Presentation
• Mycosisfungoides(limitedsuperficialtype)
■ characterized by erythematous patches/plaques/nodules/tumours, which may be pruritic and
poikilodermic (atrophy, telangiectasia, hyperpigmentation, hypopigmentation) ■ common sites include: trunk, buttocks, proximal limbs
■ mildly symptomatic, usually excellent prognosis for early disease
• Sézarysyndrome(widespreadsystemictype)
■ rare variant characterized by erythroderma, lymphadenopathy, WBC >20 x 109/L with Sézary cells
■ associated with intense pruritus, alopecia, palmoplantar hyperkeratosis, and systemic symptoms
(fatigue, fever)
■ oftenfatal
Pathophysiology
• clonalproliferationofskin-homingCD4T-cells
Epidemiology
• >50yrold,M:F2:1
Differential Diagnosis
• tineacorporis,nummulardermatitis,psoriasis,DLE,Bowen’sdisease
Investigations
• skinbiopsy(histology,“lymphocyteantigencell”markers,TcRgenearrangement)
• bloodsmearlookingforSézarycellsorflowcytometry(e.g.CD4:CD8>10isSézary) • imaging(forsystemicinvolvement)
Management
• Mycosisfungoides
■ depends on stage of disease
■ topical steroids and/or PUVA, NB-UVB (311-313 mm)
• Sézarysyndrome
■ oral retinoids and IFN
■ extra-corporeal photopheresis
■ may need radiotherapy for total skin electron beam radiation ■ maymaintainonUVtherapy
■ other chemotherapy agents
Diseases of Hair Density
Hair Growth
• hairgrowsinacyclicpatternthatisdefinedin3stages(mostscalphairsareinanagenphase) 1. growth stage = anagen phase
2. transitional stage = catagen stage
3. resting stage = telogen phase
• totaldurationofthegrowthstagereflectsthetypeandlocationofhair:eyebrow,eyelash,andaxillary hairs have a short growth stage in relation to the resting stage
• growthofthehairfolliclesisalsobasedonthehormonalresponsetotestosteroneandDHT;this response is genetically controlled
Non-Scarring (Non-Cicatricial) Alopecia
ANDROGENETIC ALOPECIA
Clinical Presentation
• male-orfemale-patternalopecia
• males:fronto-temporalareasprogressingtovertex,entirescalpmaybebald • females:wideningofcentralpart,“Christmastree”pattern
Pathophysiology
• actionofdihydrotestosterone(DHT)onhairfollicles
Epidemiology
• males:early20s-30s • females: 40s-50s
Dermatology D37
Hair Loss
TOP HAT
Telogen effluvium, tinea capitis
Out of Fe, Zn
Physical: trichotillomania, “corn-row” braiding Hormonal: hypothyroidism, androgenic Autoimmune: SLE, alopecia areata
Toxins: heavy metals, anticoagulants, chemotherapy, vitamin A, SSRls