II. Causes: Focal

  1. Diffuse
    1. Androgenetic Alopecia
      1. Male-Patterned Hair Loss (M-patterned hair thinning)
      2. Female-Patterned Hair Loss (central hair thinning)
    2. Telogen Effluvium
    3. Anagen Effluvium
    4. Systemic conditions (e.g. Hypothyroidism, Iron Deficiency Anemia, nutritional deficiency)
    5. Alopecia Totalis
  2. Focal or patchy - Nonscarring Alopecia (non-cicatrical Alopecia)
    1. Tinea Capitis
    2. Trichotillomania
    3. Traction Alopecia (e.g. tight braiding)
    4. Alopecia Areata
    5. Secondary Syphilis (Alopecia syphilitica with moth-eaten appearance)
  3. Focal or patchy - Scarring Alopecia (Cicatricial Alopecia, uncommon)
    1. Congenital defects
    2. Trauma
      1. Chemical agents (caustic substances)
      2. Burns
      3. Radiation
    3. Inflammatory dermatoses
      1. Discoid Lupus Erythematosis
      2. Sarcoidosis
      3. Lichen Planus follicularis
      4. Necrobiosis Lipoidica diabeticorum
    4. Infection
    5. Neoplasm
      1. Basal Cell Carcinoma
      2. Squamous Cell Carcinoma
      3. Metastases
      4. Lymphoma

III. History

  1. History of present illness
    1. Duration of Hair Loss
    2. Pattern of Hair Loss (see below)
    3. Progression of Hair Loss
  2. Family History of Hair Loss
    1. Androgenetic Alopecia
    2. Alopecia Areata
  3. Hair Loss type
    1. Broken hairs: Tinea Capitis, Trichotillomania
    2. Hairs lost by roots
  4. Concurrent systemic symptoms (e.g. weight loss, Fatigue) or systemic illness or endocrinopathy (e.g. Hypothyroidism)
    1. Alopecia Areata
    2. Telogen Effluvium
  5. Concurrent psychiatric illness or significant stress, pregnancy or febrile illness (with abrupt onset)
    1. Telogen Effluvium
    2. Trichotillomania
  6. Recent medication changes
    1. Telogen Effluvium
  7. Hyperandrogenism in women
    1. Androgenetic Alopecia
  8. Excessive hair care product use (straightening agents, Shampoos)
    1. Trichorrhexis Nodosa
  9. Nail changes
    1. Alopecia Areata (esp. Nail Pitting)

IV. Exam: Hair

  1. Hair distribution and areas of thinning
  2. Hair Pull Test
  3. Scalp scarring
    1. Inflammation
    2. Scaling
    3. Loss of Hair Follicles in non-scarring Alopecia
  4. Hair Shaft exam
    1. Hair length and caliber
    2. Hair fragility
  5. Scalp with Scaling, Pustules, crusts, erosions or erythema or local adenopathy
    1. Infection
  6. Dry, broken hair
    1. Trichorrhexis Nodosa

V. Signs: Patterns of Hair Loss

  1. M-Pattern in Men (bi-temporal, frontal, vertex) or central and vertex thinning (with spared frontal hair) in women
    1. Androgenetic Alopecia
  2. Diffuse Hair Loss
    1. Alopecia Areata (or if involves the entire body, Alopecia Totalis or universalis)
    2. Telogen Effluvium
    3. Toxin or Chemotherapy exposure
    4. Endocrinopathy
  3. Focal Hair Loss
    1. Traction Alopecia
    2. Trichotillomania
    3. Tinea Capitis
    4. Alopecia Areata
    5. Systemic Lupus Erythematosus
    6. Syphilis

VI. Labs

  1. Potassium Hydroxide (KOH) of scalp scraping
  2. Consider additional labs based on Alopecia type
    1. See Alopecia Areata
    2. See Androgenetic Alopecia
    3. See Telogen Effluvium
  3. Scalp Biopsy Indications (4 mm Punch Biopsy)
    1. Scarring Alopecia (not diagnostic if Trauma related)
    2. Unusual Hair Loss pattern

VII. Management

  1. Refer cicatrical Alopecia (scarring Alopecia)
  2. See specific Alopecia types for management

VIII. Resources

Images: Related links to external sites (from Bing)

Related Studies

Ontology: Alopecia (C0002170)

Definition (MSHFRE) Absence de cheveux et de poil.
Definition (MEDLINEPLUS)

You lose up to 100 hairs from your scalp every day. That's normal, and in most people, those hairs grow back. But many men -- and some women -- lose hair as they grow older. You can also lose your hair if you have certain diseases, such as thyroid problems, diabetes, or lupus. If you take certain medicines or have chemotherapy for cancer, you may also lose your hair. Other causes are stress, a low protein diet, a family history, or poor nutrition.

Treatment for hair loss depends on the cause. In some cases, treating the underlying cause will correct the problem. Other treatments include medicines and hair restoration.

Definition (NCI_NCI-GLOSS) The lack or loss of hair from areas of the body where hair is usually found. Alopecia can be a side effect of some cancer treatments.
Definition (NCI) Hair loss usually from the scalp. It may result in bald spots or spread to the entire scalp or the entire epidermis. It may be androgenetic or caused by chemotherapeutic agents, compulsive hair pulling, autoimmune disorders or congenital conditions.
Definition (NCI_CTCAE) A disorder characterized by a decrease in density of hair compared to normal for a given individual at a given age and body location.
Definition (CSP) baldness; absence of hair from skin areas where it is normally present.
Definition (MSH) Absence of hair from areas where it is normally present.
Definition (PSY) Baldness or the loss of hair.
Concepts Finding (T033)
MSH D000505
ICD9 704.00, 704.0
ICD10 L65.9
SnomedCT 156408004, 201130000, 201129005, 267810004, 270504008, 201157003, 278040002, 56317004
English Alopecias, Alopecia, Baldness, ALOPECIA, BALDNESS, HAIR THINNING, Alopecia unspecified, Alopecia, unspecified, Hair thinning, hair thinning (physical finding), hair thinning, alopecia, alopecia (physical finding), Alopecia Areata, Alopecia NOS, Alopecia [Disease/Finding], falling hairs, alopecia disorders, falls hair, Loss (of);hair, bald, hair loss, falling hair, baldness, alopecias, hair falling, thinning hair, Hair Loss, alopecia (diagnosis), (Alopecia unspecified) or (baldness) or (hair loss), (Alopecia) or (thinning of hair), (Alopecia) or (thinning of hair) (disorder), Alopecia unspecified (disorder), Thinning of hair, (Alopecia unspecified) or (baldness) or (hair loss) (disorder), Alopecia NOS (disorder), Hair absent, Hair loss, LOSS OF HAIR, HAIR LOSS, Loss of hair, Hair loss disorder, Falling hair, Thinning hair, Bald, Loss of hair (finding), Alopecia (disorder), calvities, hair; loss, loss; hair, Alopecia, NOS, loss of hair
French ALOPECIE, Alopécie, non précisée, Perte des cheveux, Raréfaction des cheveux, Atrichie, CALVITIE, CHUTE DE CHEVEUX, PERTE DE CHEVEUX, Alopécies, Alopécie, Calvitie, Atrichose
Portuguese ALOPECIA, CALVICIE, Perda de cabelo, Alopecia NE, Adelgaçamento dos pêlos, PERDA DE CABELO, QUEDA DE CABELO, Alopécias, Alopécia, Alopecia, Calvície
Spanish ALOPECIA, CALVICIE, Alopecia no especificada, Pérdida del pelo, Adelgazamiento del pelo, CABELLO, CAIDA, CABELLO, FRAGILIDAD, alopecia no especificada (trastorno), alopecia no especificada, alopecia, SAI (trastorno), alopecia, SAI, alopecia (trastorno), alopecia, calvicie, caída del cabello (hallazgo), caída del cabello, pérdida del pelo, Alopecias, Alopecia, Calvicie
German ALOPEZIE, Alopezie, unspezifisch, Haarausfall, Kahlheit, Lichtung des Haares, HAARAUSFALL, HAARE DUENNERWERDEN, KAHLKOEPFIGKEIT, Alopezien, Alopezie, Glatze, Haarlosigkeit
Italian Alopecie, Perdita di capelli, Alopecia, non specificata, Assottigliamento dei capelli, Calvizie, Alopecia
Dutch haarverlies, niet-gespecificeerde kaalheid, kaalheid, dunner worden van haar, haar; verlies, verlies; haar, alopecia, kaalhoofdigheid, Alopecia, Kaalheid
Japanese 毛髪脱落, 脱毛症、詳細不明, ダツモウショウショウサイフメイ, 毛髪菲薄化, ダツモウショウ, モウハツヒハクカ, モウハツダツラク, 男性型脱毛症, 禿頭症, 脱毛症-萎縮性, 禿髪症, 男性型禿頭症, 禿頭症-男性型, 脱毛症-男性ホルモン, 無毛症-後天性, 脱毛症-男性型, 男性ホルモン脱毛症, 萎縮性脱毛症, 脱毛症
Swedish Håravfall
Czech alopecie, plešatost, Alopecie, blíže neurčená, Plešatost, Vypadávání vlasů, Plešatosti, Řídnutí vlasů, Alopecie
Finnish Kaljuus
Polish Łysienie
Hungarian Hajelvékonyodás, Alopeciák, Alopecia, Kopaszság, Hajhullás, Alopecia, nem meghatározott
Norwegian Alopesi, Håravfall, Skallethet, Hårtap

Ontology: Anthranilate Synthase Component I (C0003170)

Concepts Amino Acid, Peptide, or Protein (T116) , Enzyme (T126)
MSH D000878
English Anthranilate Synthase Component I