Basics
Description
- Absence of hair where it normally grows
- Categorized as acquired or congenital
- Most cases are acquired: Tinea capitis is most common, followed by traumatic alopecia and alopecia areata.
- Also categorized as diffuse or localized
- Most cases of alopecia are localized and, of these, tinea capitis is the most common.
- Many normal healthy newborns lose their hair in the first few months of life.
- Hair loss may be exacerbated by friction from bedding/sleep surface, especially in atopic infants.
- Normally, about 50-100 hairs are shed and simultaneously replaced every day.
- 90% of alopecia cases are due to the following disorders:
- Tinea capitis
- Alopecia areata
- Traction alopecia
- Telogen effluvium
- Alopecia is preceded by a psychologically or physically stressful event 6-16 weeks prior to the onset of hair loss.
- Growing hairs convert rapidly to resting hairs.
Risk Factors
Genetics
- Alopecia areata
- Polygenic with variety of triggering factors
- Family history in 10-42% of cases
- Males and females equally affected
- Onset usually before age 30 years
- Monilethrix (also called beaded hair)
- A rare autosomal dominant disorder
Diagnosis
Differential Diagnosis
Consider the most likely diagnoses first.
- Infectious
- Tinea capitis
- Varicella
- Syphilis
- Congenital
- Aplasia cutis congenita
- Incontinentia pigmenti
- Oculomandibulofacial syndrome (sparse hair, hypoplastic teeth, cataracts, short stature)
- Goltz syndrome (alopecia, focal dermal hypoplasia, strabismus, nail dystrophy)
- Triangular alopecia of the frontal scalp
- Focal dermal hypoplasia
- Hair-shaft defects (trichodystrophies)
- Ectodermal dysplasias
- Nevi
- Progeria
- Nutritional
- Zinc deficiency
- Marasmus
- Kwashiorkor
- Anorexia or bulimia
- Hypervitaminosis A
- Celiac disease
- Endocrinologic
- Androgenetic alopecia
- Hypothyroidism
- Hyperthyroidism
- Hypoparathyroidism
- Hypopituitarism
- Diabetes mellitus
- Autoimmune
- Alopecia areata
- Systemic lupus erythematosus
- Scleroderma
- Trauma
- Traction alopecia
- Trichotillomania
- Scalp electrode scar from in utero monitoring
- Toxic exposures:
- Antimetabolites
- Anticoagulants
- Antithyroid medications
- Heavy metals (e.g., arsenic, lead)
- Radiation
- Stress
- Miscellaneous:
- Telogen effluvium
- Darier disease (keratotic crusted papules, keratosis follicularis)
- Lichen planus
- Burn
- Stress
Commonly Associated Conditions
- May be associated with a genetic, endocrine, or toxin-mediated condition
- Look for nail, skin, teeth, or gland involvement.
- Trichotillomania is frequently associated with a finger-sucking habit.
Approach to the Patient
- Treatment of alopecia is guided by underlying etiology.
- Systemic treatment is needed for tinea capitis; topical antifungals alone are not adequate. Selenium sulfide or ketoconazole shampoo is recommended for tinea capitis to decrease fungal shedding and risk of spread to others.
- Other than reassurance and waiting, there is no proven effective long-term therapy for alopecia areata. Topical steroids may show short-term benefit. There are no randomized clinical trials on the use of topical immunotherapy or intralesional steroids.
- Caution regarding side effects of all potential treatments.
History
- Attempt to classify the alopecia. This will guide the diagnosis and treatment plan.
- Question: Is the loss acquired or congenital? Is the alopecia treatable? Is it likely to be self-limited?
- Significance: Consider most likely diagnoses, including tinea capitis, traumatic alopecia, and alopecia areata.
- Question: Associated abnormalities?
- Significance: may be part of a syndrome
- Question: Is there an endocrine abnormality or a toxin/medication effect?
- Significance: Some of these would require prompt attention.
- Question: Assess extent of hair loss.
- Significance:
- Increased amount of hair in the brush or in the shower/tub drain?
- Does hair appear or feel thinner?
- Patches of hair loss or broken hairs noted?
- Question: Considering trichotillomania?
- Significance: Note that patients often deny hair-pulling. Direct confrontation is rarely helpful.
Physical Exam
- Assess localized versus diffuse hair loss.
- Finding: appearance of the scalp
- Significance:
- Alopecia areata: Except for well-demarcated hair loss, scalp appears normal with smooth surface.
- Tinea capitis: Scalp is often scaly and may be erythematous; areas of hair loss with broken hair stubs, referred to as black-dot alopecia.
- Finding: bizarre configuration and irregular border; hairs of varying lengths
- Significance: distinguishes traction/traumatic alopecia from alopecia areata
- Finding: short broken hairs but not black dots
- Significance: Short hairs are usually associated with trichotillomania, whereas black dot alopecia is seen with tinea capitis.
- Finding: frontal, vertex, or bitemporal decreased hair density in adolescents
- Significance: may be adolescent-onset, androgenetic alopecia
- Finding: Hair shaft varies in thickness, with small node-like deformities (like beads), increased breakage, and partial alopecia.
- Significance:
- Monilethrix
- Other hair-shaft abnormalities with increased fragility include pseudomonilethrix, trichorrhexis, pili torti, pili bifurcati, Menkes kinky hair syndrome, and trichothiodystrophy.
- Finding: associated systemic signs or any nonscalp findings
- Significance: may signify a genetic syndrome or endocrine abnormality
- Finding: nail defects such as dystrophic changes and fine stippling
- Significance:
- Nail defects are seen in 10-20% of cases of alopecia areata.
- Nail defects accompanying localized alopecia along with syndactyly, strabismus, and dermal hypoplasia may be found in Goltz syndrome.
- In ectodermal dysplasias, nails, hair, teeth, or glands may be affected.
- Finding: pubic hair and eyebrow hair loss
- Significance:
- Found in a form of alopecia areata called alopecia universalis, where nearly all body hair is lost (alopecia totalis involves the loss of all scalp hair)
- Body hair loss such as pubic hair or eyebrow hair may also occur in trichotillomania.
Diagnostic Tests & Interpretation
- Test: fungal culture
- Significance:
- Recommended when assessing for tinea capitis as a cause of alopecia
- Definitive results may take up to several weeks; may treat while awaiting results
- Using a cotton-tipped applicator, culturette, toothbrush, or direct plating on Sabouraud dextrose agar, culture will be positive for Trichophyton tonsurans in >90% of cases in North America.
- Less common are Microsporum canis, Microsporum audouinii, Trichophyton mentagrophytes, and Trichophyton schoenleinii.
- Test: dermatophyte-testing medium (DTM)
- Significance:
- Assessing for tinea capitis
- Definitive results may take from days to weeks. If dermatophyte colonies grow on the medium, the phenol red indicator in the agar will turn from yellow to red.
- Test: Wood's light (lamp) examination
- Significance:
- M. canis, M. audouinii, or T. schoenleinii fluoresces green.
- T. tonsurans does not fluoresce.
- Test: potassium hydroxide (KOH) exam
- Significance:
- The KOH exam is another way to assess for tinea capitis.
- Hyphae and spores within hair shaft indicate tinea capitis.
- With Microsporum, spores surround the hair shaft.
- Test: endocrine testing
- Significance:
- Alopecia areata or diffuse alopecia is associated with several endocrine disorders (e.g., hyperthyroidism, diabetes).
- Based on history of physical exam, consider relevant screening tests or referral to an endocrinologist or dermatologist for further evaluation.
- Routine screening for autoimmune disorders is generally not indicated.
- Test: hair-pluck test
- Significance:
- Used to determine the ratio of telogen (resting) to anagen (growing) hairs
- ~50 hairs are plucked (with 1 firm tug using a hemostat clamped around the hair ~1 cm from the scalp) and examined under the low-power lens of a microscope to determine the percentage of hairs that are telogen and anagen hairs.
- >25% telogen hairs are indicative of telogen effluvium.
- Test: scalp biopsy
- Significance:
- Can help to distinguish alopecia areata and trichotillomania
- In alopecia areata, hair follicles become small but continue to produce fine hairs; there is mitotic activity in the matrix and often inflammation is present.
- In trichotillomania, follicles are not small. They are usually in a transitional (catagen) phase and no longer produce normal hair shafts. Keratinous debris, fibrosis, and clumps of dark melanin pigment are present. Significant inflammation is absent.
- In telogen effluvium, follicles remain intact without inflammation.
Treatment
Medication
First Line
- For tinea capitis: microsize griseofulvin 20-25 mg/kg/24 h (maximum 1 g) or ultramicrosize griseofulvin 10-15 mg/kg/24 h (maximum 750 mg) orally once per day for 4-6 weeks; approved for children >2 years of age
- For alopecia areata requiring treatment: Topical corticosteroids may be used for isolated patches for short-term benefit.
Second Line
- For tinea capitis: Terbinafine, itraconazole, or fluconazole may be effective, although only terbinafine is FDA-approved for this condition.
- For alopecia areata: There is limited evidence for long-term effectiveness of any treatment. For trial of other therapies (intralesional steroid, topical immunotherapy), seek consultation with a dermatologist.
General Measures
- Treatment of alopecia is guided by the underlying cause.
- If alopecia signifies a toxic exposure or an endocrine abnormality, the underlying condition may require prompt diagnosis and treatment.
- Infectious causes of alopecia (such as with tinea capitis) should be treated promptly.
- Most patients with alopecia areata do not need treatment, as regrowth will occur spontaneously.
- Complementary and alternative medicine (CAM):
- Hypnotherapy, massage, acupuncture, and onion juice are among the complementary therapies that have been tried for conditions like alopecia areata and trichotillomania. Of note, although many patients try CAM for alopecia, more research is needed.
Ongoing Care
Prognosis
- Tinea capitis, alopecia areata, and traction alopecia
- Hair will regrow, may take months.
- There is a poorer prognosis with alopecia universalis. <10% have full recovery.
- Telogen effluvium
- Spontaneous regrowth is expected unless the stressful event continues/recurs.
- Alopecia areata may spontaneously remit and then recur.
Additional Reading
- Alkhalifah A, Alsantali A, Wang E, et al. Alopecia areata update. J Am Acad Dermatol. 2010;62(2):177-188, 191-202.
- Food and Drug Administration. Consumer updates: Lamisil approved to treat scalp ringworm in children. http://www.fda.gov/forconsumers/consumerupdates/ucm048710.htm. March 19, 2015.
- Haynes JW, Persons R, Jamieson B. Clinical inquiries: childhood alopecia areata: what treatment works best? J Fam Pract. 2011;60(1):45-52. [View Abstract]
- Hunt N, McHale S. The psychological impact of alopecia. BMJ. 2005;331(7522):951-953. [View Abstract]
- Sardesai V, Prasad S, Agarwal T. A Study to evaluate the efficacy of various topical treatment modalities for alopecia areata. Int J Trichology. 2012;4(4):265-270. [View Abstract]
- Swanson A, Canty K. Common pediatric skin conditions with protracted courses: a therapeutic update. Dermatol Clin. 2013;31(2):239-249. [View Abstract]
- National Alopecia Areata Foundation: http://www.naaf.org
- van den Biggelaar FJ, Smolders J, Jansen JF. Complementary and alternative medicine in alopecia areata. Am J Clin Dermatol. 2010;11(1):11-20. [View Abstract]
Codes
ICD09
- 704.00 Alopecia, unspecified
- 110.0 Dermatophytosis of scalp and beard
- 704.01 Alopecia areata
- 704.09 Other alopecia
- 757.4 Specified anomalies of hair
- 312.39 Other disorders of impulse control
ICD10
- L65.9 Nonscarring hair loss, unspecified
- B35.0 Tinea barbae and tinea capitis
- L63.9 Alopecia areata, unspecified
- L65.8 Other specified nonscarring hair loss
- F63.3 Trichotillomania
- Q84.0 Congenital alopecia
SNOMED
- 56317004 Alopecia (disorder)
- 5441008 Tinea capitis (disorder)
- 68225006 Alopecia areata (disorder)
- 402639004 Alopecia due to friction and trauma (disorder)
- 2965006 Congenital alopecia (disorder)
- 17155009 trichotillomania (disorder)
FAQ
- Q: When can children with tinea capitis return to school?
- A: Once treatment with a systemic antifungal has begun, the child may return to school. A topical shampoo such as selenium sulfide or ketoconazole is recommended to decrease fungal shedding and the risk of spread.
- Q: Will the hair grow back?
- A: For the 3 most common causes of childhood alopecia-accounting for 90% of cases; tinea capitis, alopecia areata, and traction alopecia-hair will regrow, but may take months to do so.