Androgenetic Alopecia Treatment
Two drugs, finasteride and minoxidil, are approved by the Food and Drug Administration (FDA) for the treatment of hair loss in men. Finasteride is an oral medication that inhibits 5-alpha reductase and blocks the conversion of testosterone to DHT (AHLA 2010; Qi 2014). Minoxidil lengthens the anagen phase, shortens the telogen phase, increases the growth rate, and increases the size of hair follicles. Minoxidil can be considered in men who do not respond adequately to finasteride treatment, or as an add-on to other treatments. Topical minoxidil is FDA approved in both 2% and 5% formulations for treatment of pattern hair loss in men and women (Ahanogbe 2015; Stough 2005).
These medications are only effective during active use, so they must be used continuously and indefinitely (Qi 2014; Levy 2013). In addition, they may cause unwanted side effects. Minoxidil may cause itching and irritation of the scalp, as well as excessive facial hair growth in women (Levy 2013). Finasteride may cause sexual dysfunction in some men (Ahanogbe 2015).
Surgical Hair Restoration Techniques
Surgical hair restoration in the form of hair transplantation is widely used to treat pattern hair loss in men and women (Cranwell 2016; Rousso 2014; Ahanogbe 2015). Different procedures are available, though the most common ones involve transplanting hair follicles taken from the rear or side and moved to the location of the hair loss, usually the crown of the head, the temples, or frontal scalp; this is called Follicular Unit Transplant, or FUT (Rousso 2014). Hair follicles from the rear and sides tend to be less sensitive to the effects of androgens, even when moved to areas of the scalp that have experienced pattern hair loss. This is believed to be a result of fewer androgen receptors and less 5-alpha reductase activity in areas of the scalp resistant to pattern hair loss (Cranwell 2016).
Strip surgery is the most widely used method of obtaining follicular units for transplant (Rousso 2014). It involves removing a linear strip of skin from the rear of the scalp and stitching the resulting wound. The strip is then separated into sections containing one hair follicle unit each, which are grafted onto areas of the scalp where hair loss has occurred. The main advantage of this technique is shorter surgery time, since the time-consuming retrieval of the follicle units occurs after the initial surgery. However, strip surgery produces a linear scar that may be visible with short hairstyles; sometimes produces local neurological side effects; and patients are advised to limit alcohol for one week, tobacco for two weeks, and vigorous activity for several weeks after the procedure (Bicknell 2014; Vogel 2013).
Follicular Unit Extraction is a newer technique that uses a punch device to extract individual hair follicle units from widely distributed sites on a large region of the scalp; the hair follicles are then immediately transplanted. Although it is expensive and time-consuming, the process leaves minimal scarring and healing is fairly rapid and without post-procedure neurological effects (Rousso 2014; Bicknell 2014; Cranwell 2016). Follicular unit extraction can utilize hair follicles from other parts of the body, including facial or chest hair, an advantage in those with sparse scalp hair. The procedure can take hours and possibly multiple sessions, but usually leaves little scarring and results in a more natural-looking distribution of hair on the donor part of the scalp (Bicknell 2014; Vogel 2013). The recent introduction of robotic devices that harvest hair follicle units with greater speed and accuracy may increase the acceptability of this procedure (Santos 2015; Rousso 2014).
With either procedure, the best results are in patients with thick hair shafts and curly hair (Vogel 2013; Rousso 2014; Cranwell 2016). Intriguingly, researchers are exploring methods to grow hair follicles in a lab that can be transplanted onto a human scalp to restore lost hair (Santos 2015).
Alopecia Areata Treatment
In about 80% of cases, alopecia areata resolves without treatment over 6 to 12 months. In patients who opt for treatment, corticosteroids that suppress the underlying autoimmune process can be applied to affected areas either as cream or injections, and oral corticosteroids are used in some cases of extensive hair loss (Ahanogbe 2015; Qi 2014). Another option in severe cases is topical immunotherapy, which uses certain chemicals to modulate local immune response (Qi 2014; Santos 2015).
Ultraviolet (UV) light therapy has been investigated as a treatment for alopecia areata. Some case reports have described successful treatment of patchy hair loss due to alopecia areata with UVB therapy; however, in rigorous trials, neither UVA nor UVB therapy have been found to be effective for alopecia areata (Shapiro 2013).
Telogen Effluvium Treatment
Telogen effluvium is generally triggered by a major physical or psychological stressor; the stressor typically occurs two to four months before hair loss begins. Hair regrowth typically occurs within four to six months if the stressor is short-lived, but if repetitive or chronic, hair loss may continue and topical minoxidil may be suggested (Qi 2014; Harrison 2009; Ahanogbe 2015).
Anagen Effluvium Prevention
Anagen effluvium is usually caused by chemotherapy or radiation therapy and normal hair regrowth typically begins within three to six months of treatment discontinuation. Scalp cooling is an effective method of preventing hair loss in some cases of chemotherapy-induced alopecia, reducing the risk of this type of hair loss by 62% (Shin 2015; FDA 2015; Qi 2014; Nangia 2017). A scalp cooling procedure that applies a refrigerated cap 30 minutes before, during, and up to 90 minutes after chemotherapy treatment is believed to prevent hair loss by reducing the amount of chemotherapeutic drug reaching the hair follicle, and lowering the rate of biochemical activity within the hair follicles (Shin 2015; FDA 2015; Qi 2014).