Updated: Sep 2, 2009
Normal human hairs can be classified according to the 3 phases of their growth cycle: anagen, catagen, and telogen. Anagen hairs are in a growing phase, during which the matrix cells of the hair follicle undergo vigorous mitotic activity. These hairs have long, indented roots covered with intact inner and outer root sheaths, and they are fully pigmented.
Toward the end of the anagen phase, the amount of pigment decreases at the base of the follicle, which expands to form a keratinized club. Then, the hair enters the catagen phase, a transitional phase in which mitotic activity decreases. The follicle separates from the dermal papilla and the capillary plexus and moves upward within its connective tissue sheath toward the epidermis. The resulting telogen hairs, or club hairs, are in a resting phase. These hairs have short, club-shaped roots that anchor them in the follicle. They lack root sheaths and show depigmentation of the proximal part of the shaft.
The hairs continue in this resting state until the follicle spontaneously reenters the anagen phase. At this point, the club hairs are forced out by growing hairs underneath them, and the cycle begins anew. The cycle is not synchronous throughout the scalp; patches of hair may be synchronized. The length of each phase of the cycle, as well as the length of the entire cycle, varies with the site and the age of the patient. In the scalp, for example, the average length of the anagen phase is 1000 days; that of the catagen phase, only a few days; and that of the telogen phase, 100 days. Of the 100,000 hairs on the average scalp, 10-15% are in the catagen or telogen phase at any time. Most hair follicles are in the anagen stage at any given time.
Hair loss can be classified according to the stage of the hairs shed. Telogen effluvium is defined as the early and excessive loss of normal club hairs from normal resting follicles in the scalp. This hair loss usually results from trauma to the normal hair as a result of a stressor such as parturition, surgery, or fever that causes an abnormally large percentage of hairs to move into the catagen and telogen phases. When anagen restarts 2-4 months later, the club hairs are pushed out and lost, causing a temporary diffuse thinning of the scalp hair.
Anagen effluvium occurs after any insult to the hair follicle that impairs its mitotic or metabolic activity. The hair loss is usually the result of an exposure to chemotherapeutic agents such as antimetabolites, alkylating agents, and mitotic inhibitors that are used to treat cancer, although it is not the only type of chemotherapy induced – hair loss in these patients.[1 ]
The inhibition or arrest of cell division in the hair matrix can lead to a narrow, weakened segment of the hair shaft that is susceptible to fracture with minimal trauma. It can also result in complete failure of hair formation. The hair bulb itself may be damaged, and the hairs may separate at the bulb and fall out. Only actively growing anagen follicles are subject to these processes. This form of alopecia is more common and severe with combination chemotherapy than with the use of a single drug, and the severity is generally dose dependent. Anagen effluvium also occurs in persons with alopecia areata as the result of the inflammatory insult to the matrix.
The characteristic finding in anagen effluvium is the tapered fracture of the hair shafts. The hair shaft narrows as a result of damage to the matrix. Eventually, the shaft fractures at the site of narrowing.
Anagen effluvium is an uncommon symptom of pemphigus vulgaris.[2 ]The hair follicle is a preferential target for pemphigus autoantibodies because the desmosomal proteins are overexpressed in the follicular epithelium. The ensuing intercellular cleavage causes the anagen hairs in lesional and perilesional areas to fall out.
Chemotherapeutics used to treat cancer are the most common causes of anagen effluvium.[3,4,5 ]
| Alopecia Areata | Telogen Effluvium |
| Alopecia Mucinosa | Tinea Capitis |
| Androgenetic Alopecia | Traction Alopecia |
| Atopic Dermatitis | Trichotillomania |
| Pemphigus Vulgaris | |
| Psoriasis, Plaque |
Hypothyroidism
Hyperthyroidism
Hypopituitarism
Diabetes mellitus
Sézary syndrome
Lymphoma
Protein malnutrition
Iron deficiency
Collagen disease
Endocrine and metabolic disorders
Infections (eg, syphilis)
Widespread skin disease
Because most scalp hair is in anagen at a given time, and telogen effluvium is dependent on the transition from anagen to telogen, with subsequent release of telogen hairs, it has a latent period of months, and the hair loss is usually subclinical, involving less than 50% of hairs.[1 ]
Anagen hairs have long, indented roots covered with intact inner and outer root sheaths. These hairs are fully pigmented. Telogen hairs have short, club-shaped roots. These hairs lack root sheaths and show depigmentation of the proximal parts of the shaft.
The goal of pharmacotherapy is to shorten the period of alopecia resulting from chemotherapy. Sadly, no treatment appears to be generally effective in preventing this secondary effect of chemotherapy. In rodent models, localized administration of heat or subcutaneous/intradermal injection of geldanamycin or 17-(allylamino)-17-demethoxygeldanamycin induced a stress-protein response in hair follicles and effectively prevented alopecia from doxorubicin (Adriamycin), cyclophosphamide, paclitaxel (Taxol), and etoposide.[11 ]Hopefully, localized hair-saving treatment can be developed for humans that does not negatively affect chemotherapy efficacy.
Minoxidil directly dilates the peripheral vessels. Although the exact mechanism of action for promoting hair growth remains unknown, increased blood flow to the hair follicles may affect their metabolism and growth cycle and thereby prevent hair loss.
Relaxes arteriolar smooth muscle, causing vasodilation; hair growth possibly secondary to vasodilation. Available in 2% and 5% solutions; 5% solution recommended only for men.
Apply 1 mL to scalp bid
Not established
Concurrent guanethidine, diuretics, or hypotensive agents may result in additive hypotension
Documented hypersensitivity; pheochromocytoma; acute MI; dissecting aortic aneurysm
C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus
May exacerbate angina pectoris; caution in pulmonary hypertension, congestive heart failure, coronary artery disease, significant renal failure, impaired liver function, and patients >50 y; common adverse effects include contact dermatitis, itching, and skin irritation
Trueb RM. Chemotherapy-induced alopecia. Semin Cutan Med Surg. Mar 2009;28(1):11-4. [Medline].
Delmonte S, Semino MT, Parodi A, Rebora A. Normal anagen effluvium: a sign of pemphigus vulgaris. Br J Dermatol. Jun 2000;142(6):1244-5. [Medline].
Bronner AK, Hood AF. Cutaneous complications of chemotherapeutic agents. J Am Acad Dermatol. Nov 1983;9(5):645-63. [Medline].
Tosi A, Misciali C, Piraccini BM, Peluso AM, Bardazzi F. Drug-induced hair loss and hair growth. Incidence, management and avoidance. Drug Saf. Apr 1994;10(4):310-7. [Medline].
Tosti A, Pazzaglia M. Drug reactions affecting hair: diagnosis. Dermatol Clin. Apr 2007;25(2):223-31. [Medline].
van Beek N, Bodo E, Kromminga A, et al. Thyroid hormones directly alter human hair follicle functions: anagen prolongation and stimulation of both hair matrix keratinocyte proliferation and hair pigmentation. J Clin Endocrinol Metab. Nov 2008;93(11):4381-8. [Medline].
Trovato MJ, Schwartz RA, Janniger CK. Tinea capitis: current concepts in clinical practice. Cutis. Feb 2006;77(2):93-9. [Medline].
Duvic M, Lemak NA, Valero V, Hymes SR, et al. A randomized trial of minoxidil in chemotherapy-induced alopecia. J Am Acad Dermatol. Jul 1996;35(1):74-8. [Medline].
Merial-Kieny C, Nocera T, Mery S. [Medical corrective make-up in post- chemotherapy]. Ann Dermatol Venereol. Jan 2008;Spec No 1:25-8. [Medline].
[Guideline] University of Texas at Austin, School of Nursing, Family Nurse Practitioner Program. Recommendations to diagnose and treat adult hair loss disorders or alopecia in primary care settings (non pregnant female and male adults). National Guidelines Clearinghouse. May 2004.
Jimenez JJ, Roberts SM, Mejia J, et al. Prevention of chemotherapy-induced alopecia in rodent models. Cell Stress Chaperones. Spring 2008;13(1):31-8. [Medline].
Bleiker TO, Nicolaou N, Traulsen J, Hutchinson PE. 'Atrophic telogen effluvium' from cytotoxic drugs and a randomized controlled trial to investigate the possible protective effect of pretreatment with a topical vitamin D analogue in humans. Br J Dermatol. Jul 2005;153(1):103-12. [Medline].
Brandy DA. A technique for hair-grafting in between existing follicles in patients with early pattern baldness. Dermatol Surg. Aug 2000;26(8):801-5. [Medline].
Kemmett D. ABC of dermatology. Diseases of the hair and scalp. Br Med J (Clin Res Ed). Feb 20 1988;296(6621):552-5. [Medline].
Mohrenschlager M, Ring J, Kohn FM. [Acquired effluvium of head hair: common conditions in women]. MMW Fortschr Med. Oct 27 2005;147(43):37-40. [Medline].
Sommer M, Wilson C. Therapeutic approaches to the management of common baldness. Int J Clin Pract. Jul-Aug 1999;53(5):381-5. [Medline].
Spencer LV, Callen JP. Hair loss in systemic disease. Dermatol Clin. Jul 1987;5(3):565-70. [Medline].
Sperling LC, Mezebish DS. Hair diseases. Med Clin North Am. Sep 1998;82(5):1155-69. [Medline].
Walkden V. Hair and scalp conditions. Practitioner. Apr 1998;242(1585):278-81. [Medline].
Whiting DA. Structural abnormalities of the hair shaft. J Am Acad Dermatol. Jan 1987;16(1 Pt 1):1-25. [Medline].
anagen effluvium, chemotherapy-induced alopecia, defluvium, telogen effluvium, hair loss, alopecia, catagen
Robert A Schwartz, MD, MPH, Professor and Head, Dermatology, Professor of Pathology, Pediatrics, Medicine, and Preventive Medicine and Community Health, UMDNJ-New Jersey Medical School
Robert A Schwartz, MD, MPH is a member of the following medical societies: Alpha Omega Alpha, American Academy of Dermatology, American College of Physicians, and Sigma Xi
Disclosure: Nothing to disclose.
Bryan D Seiff, MD, Staff Physician, Department of Ophthalmology, NY Presbyterian Hospital-Cornell
Bryan D Seiff, MD is a member of the following medical societies: Alpha Omega Alpha
Disclosure: Nothing to disclose.
Pere Gascon, MD, PhD, Professor and Director, Division of Medical Oncology, Institute of Hematology and Medical Oncology, IDIBAPS, University of Barcelona Faculty of Medicine, Spain
Pere Gascon, MD, PhD is a member of the following medical societies: Alpha Omega Alpha, American College of Physicians, New York Academy of Medicine, New York Academy of Sciences, and Sigma Xi
Disclosure: Nothing to disclose.
Günter Burg, MD, Professor and Chairman Emeritus, Department of Dermatology, University of Zürich School of Medicine; Delegate of The Foundation for Modern Teaching and Learning in Medicine Faculty of Medicine, University of Zürich, Switzerland
Günter Burg, MD is a member of the following medical societies: American Academy of Dermatology, American Dermatological Association, International Society for Dermatologic Surgery, North American Clinical Dermatologic Society, and Pacific Dermatologic Association
Disclosure: Nothing to disclose.
David F Butler, MD, Professor of Dermatology, Texas A&M University College of Medicine; Chair, Department of Dermatology, Director, Dermatology Residency Training Program, Scott and White Clinic, Northside Clinic
David F Butler, MD is a member of the following medical societies: Alpha Omega Alpha, American Academy of Dermatology, American Medical Association, American Society for Dermatologic Surgery, American Society for MOHS Surgery, Association of Military Dermatologists, and Phi Beta Kappa
Disclosure: Nothing to disclose.
Rosalie Elenitsas, MD, Herman Beerman Associate Professor of Dermatology, University of Pennsylvania School of Medicine; Director, Penn Cutaneous Pathology Services, Department of Dermatology, University of Pennsylvania Health System
Rosalie Elenitsas, MD is a member of the following medical societies: American Academy of Dermatology and American Society of Dermatopathology
Disclosure: Nothing to disclose.
Catherine Quirk, MD, Clinical Assistant Professor, Department of Dermatology, Brown University
Catherine Quirk, MD is a member of the following medical societies: Alpha Omega Alpha and American Academy of Dermatology
Disclosure: Nothing to disclose.
Dirk M Elston, MD, Director, Department of Dermatology, Geisinger Medical Center
Dirk M Elston, MD is a member of the following medical societies: American Academy of Dermatology
Disclosure: Nothing to disclose.
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