The cyclic phases of hair growth are essential in understanding the majority of the pathologies related to hair loss. The human hair growth cycle is in fact divided into three phases: Anagen, Catagen, and Telogen. The Anagen is known as the growing phase, during which the cells of the hair follicle exhibit vigorous mitotic activity and multiply. Approximately 90% of all hair is present in the anagen phase of the cycle at any given time.
What is Anagen Effluvium?
Anagen Effluvium is a non-scarring type of hair loss that occurs secondary to an acute injury to the hair follicles by an endogenous or exogenous cause. The diffuse hair shedding occurs during the anagen phase of the hair cycle, secondary to chemotherapy medications or radiation. This damage to the hair bulb and matrix leads to a cessation of mitotic activity occurring in hair strands in the anagen phase, resulting in breakage and ultimately complete hair loss.
It is necessary to distinguish Anagen Effluvium from Telogen Effluvium, a condition that occurs due to the premature entry of hair follicles into the telogen phase, as that is triggered by stressors such as pregnancy, physical and mental illnesses, and hospitalization, NOT chemotherapy agents.
Who gets Anagen Effluvium?
Classically, patients receiving systemic chemotherapy or radiation therapy are prone to observe hair loss. Several chemotherapy drugs, such as Doxorubicin, Nitrosoureas, and Cyclophosphamide, have been implicated in the pathogenesis of Anagen Effluvium. A study following 384 subjects undergoing chemotherapy showed Anagen Effluvium to be prevalent in 78% of the patients.
Other drugs include Colchicine, Cyclosporine, Isoniazid, Levodopa, and heavy metals such as Boron, Bismuth, Copper, Cadmium, and Mercury.
The condition may also be seen in patients suffering from inflammatory disorders such as Alopecia Areata, Pemphigus Vulgaris, and in severe protein-energy malnutrition states (e.g., Kwashiorkor). Radiation therapy has also been linked to causing both reversible and irreversible alopecia.
What are the clinical features of Anagen Effluvium?
Patients with Anagen Effluvium present with diffuse hair loss after exposure to the offending drug. The most severe hair loss is seen with chemotherapy medications such as Doxorubicin, Nitrosoureas, and Cyclophosphamide. Hair fall begins within 7-14 days after receiving a single pulse of chemotherapy and becomes grossly apparent after 1-2 months.
The hair loss is not only evident on the scalp but may also occur in other hairy parts of the body including, eyebrows, eyelashes and facial hair, etc. The hair loss can be extensive and may result in partial or complete baldness over weeks.
How is it diagnosed?
The diagnosis of Anagen Effluvium is established with the help of proper history and physical exam. The patient is questioned about the pattern of hair loss and the recent use of medication. Inspection of hair and scalp is also done to rule out any signs of local disease. In Anagen Effluvium, the hallmark physical exam finding is a tapered fracture of the hair shaft visible to both the naked eye and microscope.
If the clinical findings are unclear, a biopsy is performed to exclude other causes of alopecia, although this happens quite rarely. Before the biopsy, lab investigations can also be done to look for systemic diseases that cause hair loss. These include iron studies, thyroid function tests, blood workup for syphilis, and antibody tests for Systemic Lupus Erythematosus.
What is the treatment for Anagen Effluvium?
It is essential to remember that Anagen Effluvium is a temporary condition and usually resolves once the chemotherapy, or any other cause, is removed. However, treatment is offered to people who manifest deep aesthetic concerns during this period. The main aim of the therapy here is to shorten the duration of Anagen Effluvium, as currently, no single drug has shown the potential to completely prevent hair loss. A variety of methods and medications are recommended to achieve the above-mentioned goal:
- Application of topical minoxidil has been observed to shorten the period of baldness by approximately fifty days, according to multiple studies.
- Several oncology centers practice limited drug delivery to the scalp by application of a scalp tourniquet during the treatment. The proposed idea is to decrease the blood flow to the scalp resulting in reduced delivery of the toxin to the hair. However, in cases of circulating malignant cells or hematologic malignancies like leukemia and lymphoma, such practice may not be suitable.
- Similar to pressure cuffs, induction of hypothermia to the scalp is also believed to hinder the delivery of chemotherapeutic agents. It can be carried out by application of a cooling agent with the aid of a cooling cap or by continuous cooling with cold air or liquid. However, the limitation of this therapeutic modality is similar to that of the scalp tourniquet.
- A medically corrective preparation makeup is also often offered to patients suffering from eyebrow alopecia to address cosmetic concerns and improve self-esteem.
What are the outcomes for anagen effluvium?
Chemotherapy-induced alopecia can have devastating psychological and emotional outcomes on the suffering patient. A significant population of terminal patients might even refuse potentially life-saving or palliation treatment due to the fear of it resulting in baldness. It is thus essential to counsel patients that Anagen Effluvium is, fortunately, a reversible condition where the hair follicles resume normal growth cycle once the toxic agent is withdrawn. Complete hair growth is usually observed 3-6 months after the cessation of the treatment. Occasionally, the hair which regrows after chemo may be of different color or texture in comparison to the hair had before the condition.
However, Anagen Effluvium secondary to alopecia areata has an unpredictable recovery and may persist for a longer duration.
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