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| Image = Alopecia.jpg| | | Image = Alopecia.jpg| |
| Caption = Alopecia as male pattern baldness at age 40| | | Caption = Alopecia as male pattern baldness at age 40| |
| DiseasesDB = 14765 |
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| ICD10 = {{ICD10|L|65|9|l|60}} |
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| ICD9 = {{ICD9|704.09}} |
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| ICDO = |
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| OMIM = |
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| MedlinePlus = 003246 |
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| MeshID = D000505 |
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| }} | | }} |
| {{Alopecia}} | | {{Alopecia}} |
| | '''For patient information, click [[Alopecia (patient information)|here]]''' |
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| {{CMG}} | | {{CMG}}; {{AE}} {{KS}} [[Ogechukwu Hannah Nnabude, MD]] |
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| {{SK}} Atrichia; hair loss | | {{SK}} Atrichia; hair loss; bald; baldness; balding; hypotrichosis |
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| ==Overview== | | ==[[Alopecia overview|Overview]]== |
| '''Alopecia''' is the resulting condition from the loss of hair, which is termed ''effluvium.'' It should be distinguished from [[baldness]], which is the ''lack'' of hair, including contexts where that absence is intentional. (In some cases the terms are used interchangeably, and in some conditions such as [[trichotillomania]], where the loss of the hair is due to intentional acts, but the motive for that act is defined as a medical condition, it can be difficult to determine whether the label "alopecia" is appropriate.)
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| Alopecia is characterized by scarring or non-scarring. Scarring alopecia is caused by numerous dermatologic factors, including glabrous skin (non-hairy), and is very difficult to diagnose and manage. Non-scarring alopecia is characterized by the absence of visible inflammation of the skin involved. | | ==[[Alopecia historical perspective|Historical Perspective]]== |
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| == Vocabulary == | | ==[[Alopecia classification|Classification]]== |
| *[[Anagen]]:growth phase, lasts 2-3 years (80-90% of follicles at any given time)
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| *[[Catagen]]:involutional phase, lasts 2-3 weeks (1-3% of follicles)
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| *Telogen:resting phase, lasts 3-4 months (5-10% of follicles)
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| :*hair released from shaft and shed at end of telogen new cycle begins
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| :*mature root sheath of telogen hair = “club” at proximal end
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| *[[Terminal hair]]s: large shaft diameters, bulbs extend into subcutaneous fat
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| *[[Vellus hair]]s:smaller in caliber and length, less pigmented
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| *Indeterminate hairs:size/length between that of terminal and vellus hairs
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| == Risk Factors == | | ==[[Alopecia pathophysiology|Pathophysiology]]== |
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| == Pathophysiology & Etiology== | | ==[[Alopecia causes|Causes]]== |
| '''Non Scarring'''<br>
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| ''Diffuse''
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| *[[Androgenetic alopecia]]
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| :*most common (30-40% of men and women)
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| :*Genetically determined: [[polygenic]] with [[variable penetrance]]
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| :*Shortening of anagen phase follicular miniaturization
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| :*Men: M-shaped pattern along frontal hairline (temporal loss progresses to midscalp)
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| :*Women: more diffuse, can be difficult to distinguish from telogen effluvium
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| *[[Telogen effluvium]]
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| :*Reversible loss of mature, terminal hairs (few hundred per day)
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| :*[[Stress]]ful event (or [[medication]]) triggers transition of more anagen hairs into telogen phase
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| ::*[[Childbirth]], [[fever]], severe [[infection]], severe [[psychologic stress]], major [[surgery]], [[crash diet]]
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| ::*[[Drugs]]: [[heparin]], [[antithyroid agents]], [[anticonvulsants]], [[hormones]]
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| :*Diffuse hair loss peaks 3-4 months after inciting event
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| :*Up to 30% of hairs must be lost before cosmetically apparent
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| *Anagen effluvium
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| :*Acute loss of anagen hair = 80-90% of hair
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| :*Occurs 10-14 days after treatment with [[antimitotic agents]] ([[chemo]])
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| ''Focal''
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| *[[Alopecia areata]]: incidence 1/1000
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| :*Smooth, discrete, circular areas of complete hair loss occurring over a few weeks
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| :*Exclamation point hairs: hair root narrower than normal with less pigment
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| :*Can occur on any hair-bearing area; nails may also have proximal pitting
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| :*Usually reversible: regrowth occurs over several months; 90% regrow within 2 years
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| :*Relapse occurs in up to 1/3
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| :*Decreased chance of regrowth/increased risk relapse if:
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| ::*Prepubertal onset
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| ::*Widespread involvement ([[alopecia totalis]] or [[Alopecia universalis|universalis]])
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| ::*Duration > 5 years
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| ::*History of [[atopy]]
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| :*Possible [[autoimmune]] mechanism: bx shows [[T-cell]] infiltrates around hair follicles
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| :*Positive [[family history]] in 20%
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| *[[Syphilis]]
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| :*Moth-eaten, patchy pattern of loss (may be diffuse)
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| :*May be associated with [[skin lesions]] of [[secondary syphilis]], or may occur in [[Latent syphilis|latent stage]]
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| :*Full hairgrowth occurs after treatment of [[infection]]
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| *[[Trauma]]
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| :*[[Traction alopecia]]: due to hairstyles that impose chronic tension on hair (braids)
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| :*Hair loss most prominent in areas of greatest tension (margins)
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| :*Fine, [[vellus hair]]s present in areas of absent [[terminal hair]]s
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| :*Regrowth can occur in early disease (few months-yrs), but not in late disease (years)
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| :*Chemical trauma: repeated use of [[lye]]-containing straightening agents or hot oils for styling
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| :*[[Trichotillomania]]: bizarre, asymmetric pattern of broken hairs of varying length
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| '''Scarring'''
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| *uncommon; hair loss is permanent
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| *erythematous papules, pustules, or scaling centered around follicles
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| *polytrichia = multiple hair shafts exiting a single enlarged orifice
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| *eventual obliteration of follicular orifices
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| *[[Tinea capitis]]
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| :*Scaling and [[inflammation]] in patchy areas of hair loss, +/- [[lymphadenopathy]]
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| :*Usually in children
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| :*KOH prep positive
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| *Central, centrifugal scarring alopecia (a.k.a. follicular degeneration syndrome, pseudopelade)
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| :*Symmetric involvement of central portion of scalp with outward expansion over months/yrs
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| :*May be associated with pustules (folliculitis decalvans)
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| :*Cause unknown-> emipiric [[Rx]] with [[steroids]], [[antibiotics]]
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| *[[Discoid lupus]]
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| :*[[Inflammation]] with plugged follicles, scale, abnormal scalp pigmentation
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| :*May have discoid [[lesion]]s elsewhere on body
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| == Diagnosis == | | ==[[Alopecia differential diagnosis|Differentiating Alopecia from other Diseases]]== |
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| *Pull test: firm pull on 20-40 hairs should yield fallout of no more than 1 in 10 hairs
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| :*Increased # telogen hairs with depigmented proximal bulb: [[telogen effluvium]]
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| :*Increased # hairs with no bulb: breakage (hair fragility due to exogenous injury)
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| :*[[Anagen hair]]s with pigmented root: likely excessive force
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| *Follicular units: number of hairs produced per follicular orifice
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| :*Threes = normal for ages 20-40
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| :*Twos = normal for ages 40-60
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| :*Ones = normal for ages >60
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| :*Voids = follicular orifices w/o hairs suggests advanced [[androgenetic alopecia]] if no scarring
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| *Testing:minimal
| | ==[[Alopecia epidemiology and demographics|Epidemiology and Demographics]]== |
| :*[[Medical illness]] suspected: [[CBC]], [[TSH]], possibly [[ferritin]]
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| :*[[RPR]] if patchy or unexplained loss
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| :*KOH prep if patchy alopecia with scaling or [[inflammation]]
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| ==Complete Differential Diagnosis for Alopecia== | | ==[[Alopecia risk factors|Risk Factors]]== |
| === Non-Scarring Alopecia ===
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| * [[Adrenocortical insufficiency]] (primary or secondary)
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| * [[Anagen]] effluvium (anagen=growing hair)
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| * [[Cushing's syndrome]]
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| * Diffuse hair thinning due to [[metabolic]] causes
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| * [[Hyperthyroidism]]
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| * [[Hypoparathyroidism]]
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| * [[Hypothyroidism]]
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| * [[Pituitary insufficiency]]
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| * [[Secondary syphilis]]
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| * [[Sheehan's syndrome]]
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| * Temporary hair loss
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| *:* [[Pregnancy]]
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| *:* [[Malnutrition]]
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| *:*:* [[Malabsorption]]
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| *:*:* [[Protein deficiency]]
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| *:*:* [[Tryptophan]] deficiency
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| *:*:* [[Nontropical sprue]]
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| *:*:* [[Vitamin A deficiency]]
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| *:*:* [[Vitamin B deficiency]]
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| *:*:* [[Vitamin D deficiency]]
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| *:*:* [[Rickets]]
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| * [[Telogen effluvium]] (telogen=resting hair)
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| * [[Thyroiditis]]
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| * [[Trichotillomania]]
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| === Scarring Alopecia === | | ==[[Alopecia natural history, complications and prognosis|Natural History, Complications and Prognosis]]== |
| * [[Amyloidosis]]
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| * Chronic disciform [[lupus erythematosis]]
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| * [[Congenital defect]]s
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| * [[Discoid Lupus Erythematosus]]
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| * Dissecting [[cellulitis]]
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| * [[Herpes zoster infection]]
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| * [[Infection]]
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| *:* [[Favus]]
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| *:* [[Typhoid Fever]]
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| *:* [[Leptospirosis]]
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| *:* [[Secondary syphilis]]
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| * Inflammatory [[dermatoses]]
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| * [[Lichen planopilaris]]
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| * [[Lymphoma]]
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| * [[Morphea]]
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| * [[Mycosis fungoides]]
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| * [[Neoplasm]]
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| * [[Neurodermatitis]]
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| * Physical or chemical agents:
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| *:* [[ACE inhibitors]]
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| *:* [[Allopurinol]]
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| *:* [[Androgens]]
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| *:* [[Anticoagulants]]
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| *:* [[Anticonvulsants]]
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| *:* [[Antimycotic agents]]
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| *:* [[Arsenic]]
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| *:* [[Azathioprine]]
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| *:* [[Beta blockers]]
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| *:* [[Borates]]
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| *:* [[Cadmium]]
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| *:* [[Chemotherapeutics]]
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| *:* [[Chlorambucil]]
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| *:* [[Cisplatin]]
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| *:* [[Clofibrate]]
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| *:* [[Cyclophosphamide]]
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| *:* [[Cytarabine]]
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| *:* [[Estrogens]]
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| *:* [[Fluororacil]]
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| *:* [[Gentamycin]]
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| *:* [[Gold compounds]]
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| *:* [[Heparins]]
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| *:* [[Indomethacin]]
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| *:* [[Levodopa]]
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| *:* [[Linolic acid]]
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| *:* [[Mercury]] and derivatives
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| *:* [[Methotrexate]]
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| *:* [[Niacin]]
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| *:* [[Oral contraceptives]]
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| *:* [[Propranolol]]
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| *:* [[Retinoids]]
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| *:* [[Salicylates]]
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| *:* [[Selenium]]
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| *:* [[Squalenes]]
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| *:* [[Steroids]]
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| *:* [[Thallium]]
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| *:* [[Undecylenic acid]]
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| *:* [[Vitamin A overdose]]
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| *:* [[Warfarin]]
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| * [[Pseudofolliculitis barbae]]
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| * [[Psoriasis]]
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| * [[Sarcoidosis]]
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| * [[Scleroderma]]
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| * [[Systemic Lupus Erythematosus]]
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| === Miscellaneous === | | ==Diagnosis== |
| * [[Addison's Disease]]
| | [[Alopecia diagnostic study of choice|Diagnostic study of choice]] | [[Alopecia history and symptoms|History and Symptoms]] | [[Alopecia physical examination|Physical Examination]] | [[Alopecia laboratory findings|Laboratory Findings]] | [[Alopecia electrocardiogram|Electrocardiogram]] | [[Alopecia x ray|X-Ray Findings]] | [[Alopecia echocardiography and ultrasound|Echocardiography and Ultrasound]] | [[Alopecia CT scan|CT-Scan Findings]] | [[Alopecia MRI|MRI Findings]] | [[Alopecia other imaging findings|Other Imaging Findings]] | [[Alopecia other diagnostic studies|Other Diagnostic Studies]] |
| * [[Anemia]]
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| * [[Cancer]]
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| * [[Diabetes Mellitus]]
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| * [[Pneumonia]]
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| * [[Scarlet Fever]]
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| * [[Schmidt's Syndrome]]
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| * [[Stress (medicine)|Stress]]
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| *:* [[Childbirth|Labor]]
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| *:* [[Surgery]]
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| * [[Androgen insensitivity syndrome|Testicular feminization syndrome]]
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| * [[Turner's Syndrome]]
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| * [[Typhoid fever]]
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| * Mechanical effects
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| :* Traction alopecia
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| :* Pressure alopecia
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| :*: Alopecia after extended bed rest
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| :* Trichotillomania (compulsion to pull out one’s own hair)
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| == History and Symptoms ==
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| *Age
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| :*Childhood: only 2 common diagnoses [[tinea capitis]], [[alopecia areata]]
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| :*Adulthood: [[tinea capitis]] rare; all the rest possible
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| *Duration
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| :*<1 year: suggests [[telogen effluvium]] if diffuse loss
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| :*>1 year: suggests [[androgenetic alopecia]] if diffuse loss
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| :*Pattern of loss
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| :*Shedding: “lots of hair coming out,” may be due to hair breakage or loss by the root
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| :*Thinning: scalp more visible without noticeable hair fallout, suggests [[androgenetic alopecia]]
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| :*[[Family history]]: may be positive in [[androgenetic alopecia]], [[alopecia areata]]
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| :*Grooming practices: can cause hair fragility/breakage
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| :*Chemical treatments (relaxers, perms, bleaching) most damaging; hair dye less so
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| Traction styling<br>
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| == Physical Examination ==
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| === Appearance of the Patient ===
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| *[[Scalp]]
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| :*Normal or with features of [[scarring]]
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| :*if scalp abnormal provide clues to dx
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| ::*scaling
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| ::*[[erythema]]
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| ::*[[pustules]]
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| ::*dyspigmentation
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| *Pattern: diffuse or patchy
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| :*Male pattern (diffuse):bitemporal recession +/or vertex loss
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| :*Female pattern (diffuse):coronal thinning with preserved anterior hairline
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| :*Patchy:with preserved hair of variable length (breakage)
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| ::*with exclamation point hairs ([[alopecia areata]])
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| ::*with no hair ([[scarring]], traction, [[syphilis]], [[tinea]])
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| *Patient may also have nails that have a hammered brass appearance.
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| == Laboratory Findings ==
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| * [[Viral culture|Viral]] and [[bacterial cultures]]
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| * [[Prolactin]]
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| * [[Thyroid function tests]]
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| * [[Iron]] studies
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| * [[Dehydroepiandrosterone-sulfate]] ([[DHEA-S]])
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| * [[Testosterone]]
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| * [[Rapid plasma reagin]] ([[RPR]])
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| * [[Erythrocyte sedimentation rate]] ([[ESR]])
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| * [[Antinuclear antibodies]] ([[ANA]])
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| ==Treatment== | | ==Treatment== |
| * Goal of [[treatment]] is to avoid future hair loss.
| | [[Alopecia medical therapy|Medical Therapy]] | [[Alopecia surgery|Surgery]] | [[Alopecia primary prevention|Primary Prevention]] | [[Alopecia secondary prevention|Secondary Prevention]] | [[Alopecia cost-effectiveness of therapy|Cost-Effectiveness of Therapy]] | [[Alopecia future or investigational therapies|Future or Investigational Therapies]] |
| * [[Scarring]] hair loss prevents hair from going back.
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| * Wigs and [[hair transplants]]
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| * Anagen effluvium
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| *:* Treat [[illness]] or withdraw [[drug]]
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| * [[Telogen effluvium]]
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| *:* [[Stress]] the recovery is normal
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| * Treat underlying cause of alopecia
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| == Acknowledgements == | | == Acknowledgements == |
| The content on this page was first contributed by: Steven Wiviott, M.D. | | The content on this page was first contributed by: Steven Wiviott, M.D. |
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| ==References==
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| [http://www.calosol.com/alopecia.php Alopecia Types] - More information about alopecia and the various different types{{reflist}}
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| <br>
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| [[ro:Alopecia]] | | [[ro:Alopecia]] |
