II. Physiology
- See Hair
III. Causes
- Diffuse Hair Loss
- Telogen Effluvium
- Anagen Effluvium
- Systemic conditions (e.g. Hypothyroidism, Iron Deficiency Anemia, nutritional deficiency)
- Alopecia Totalis
- Patterned Hair Loss
- Androgenetic Alopecia
- Male-Patterned Hair Loss (M-patterned hair thinning)
- Female-Patterned Hair Loss (central hair thinning)
- Androgenetic Alopecia
- Focal or patchy Hair Loss - Nonscarring Alopecia (non-cicatrical Alopecia)
- Tinea Capitis
- Most common cause of Hair Loss in children
- Slow evolving scaly, pruritic patches of Hair Loss
- Trichotillomania
- Traction Alopecia (e.g. tight braiding)
- Alopecia Areata
- Secondary Syphilis (Alopecia syphilitica with moth-eaten appearance)
- Tinea Capitis
- Focal or patchy Hair Loss - Scarring Alopecia (Cicatricial Alopecia, uncommon)
- Congenital defects
- Trauma
- Chemical agents (caustic substances)
- Burns
- Radiation
- Inflammatory dermatoses
- Discoid Lupus Erythematosis
- Sarcoidosis
- Lichen Planus follicularis
- Necrobiosis Lipoidica diabeticorum
- Infection
- Neoplasm
IV. History
- History of present illness
- Duration of Hair Loss
- Pattern of Hair Loss (see causes above, and signs below)
- Progression of Hair Loss
- Family History of Hair Loss
- Hair Loss type
- Broken hairs: Tinea Capitis, Trichotillomania
- Hairs lost by roots
- Concurrent systemic symptoms (e.g. weight loss, Fatigue) or systemic illness or endocrinopathy (e.g. Hypothyroidism)
- Concurrent psychiatric illness or significant stress, pregnancy or febrile illness (with abrupt onset)
- Recent medication changes
- Hyperandrogenism in women
- Excessive hair care product use (straightening agents, Shampoos)
- Tight hair braiding
- Nail changes
- Alopecia Areata (esp. Nail Pitting)
V. Exam: Hair
- Diagnostics
- Hair distribution and areas of thinning
- Hair Pull Test
- Trichoscopy (dermatology)
- Dermoscopy (dermatology)
- Scalp scarring
- Inflammation
- Scaling
- Loss of Hair Follicles in non-scarring Alopecia
- Hair Shaft exam
- Scalp with Scaling, Pustules, crusts, erosions or erythema or local adenopathy
- Infection
- Dry, broken hair
VI. Signs: Patterns of Hair Loss
- See causes above
- Patterned
- Androgenetic Alopecia
- Men: M-Pattern (bi-temporal, frontal, vertex)
- Women: Central and vertex thinning (with spared frontal hair)
- Androgenetic Alopecia
- Diffuse Hair Loss
- Alopecia Areata (if involves the entire body, Alopecia Totalis or universalis)
- Telogen Effluvium
- Toxin or Chemotherapy exposure
- Endocrinopathy
- Focal Hair Loss
- Traction Alopecia (esp. loss along the hair line)
- Trichotillomania (irregularly shaped patches of Hair Loss)
- Tinea Capitis
- Alopecia Areata
- Systemic Lupus Erythematosus
- Syphilis
VII. Labs
- Potassium Hydroxide (KOH) of scalp scraping
- Microscopy
- Telogen hairs (club-shaped hairs)
- AnagenHairs (inner root sheath still attached)
- Exclamation Point Hairs (club Hair Root, thinned proximal Hair Shaft, normal distal Hair Shaft)
- Consider additional labs based on Alopecia type (e.g. TSH, Hgb, LFTs)
- Scalp Biopsy Indications (4 mm Punch Biopsy)
- Scarring Alopecia (not diagnostic if Trauma related)
- Unusual Hair Loss pattern
VIII. Management
- Refer cicatrical Alopecia (scarring Alopecia)
- See specific Alopecia types for management
IX. Resources
- National Alopecia Areata Foundation
X. References
- Dakkak (2024) Am Fam Physician 110(3): 243-50 [PubMed]
- Nielson (1995) Am Fam Physician 51:1513-28 [PubMed]
- Phillips (2017) Am Fam Physician 96(6): 371-8 [PubMed]
- Price (1999) N Engl J Med 341:964-73 [PubMed]
- Shapiro (2000) Can Fam Physician 46:1469-77 [PubMed]
- Sperling (1998) Med Clin North Am 82:1155-69 [PubMed]
- Springer (2003) Am Fam Physician 68(1):93-102 [PubMed]
Images: Related links to external sites (from Bing)
Related Studies
| 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, ﾀﾞﾂﾓｳｼｮｳｼｮｳｻｲﾌﾒｲ, 毛髪菲薄化, ﾀﾞﾂﾓｳｼｮｳ, ﾓｳﾊﾂﾋﾊｸｶ, ﾓｳﾊﾂﾀﾞﾂﾗｸ, 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 |
| Russian | ANDROGENETICHESKOE OBLYSENIE, OBLYSENIE, PLESHIVOST', ALOPETSIIA, OBLYSENIE PO MUZHSKOMU TIPU, АЛОПЕЦИЯ, АНДРОГЕНЕТИЧЕСКОЕ ОБЛЫСЕНИЕ, ОБЛЫСЕНИЕ, ОБЛЫСЕНИЕ ПО МУЖСКОМУ ТИПУ, ПЛЕШИВОСТЬ |
| Croatian | ALOPECIA |
| 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 |
