Hair loss is a prevalent condition affecting men, women and children for a variety of different reasons (Gordon and Tosti, 2011). Patients present in aesthetic clinics seeking effective hair loss treatments to prevent further thinning and to optimally stimulate regrowth (Kanti et al, 2018). Hair is an important feature of image; strong and dense hair is associated with youth, beauty, healthiness and success. Consequently, loss of hair can often cause psychological distress (Gordon and Tosti, 2011; Kanti et al, 2018).
Androgenic alopecia (AGA) is a non-scarring, benign form of alopecia, unfortunately, scarring alopecias cause destruction of the hair follicle, as well as scar tissue, meaning that hair can never grow back, and treatment must be started as soon as possible to stop further scarring. In almost all cases, hair loss is benign and is not contagious, unless linked to an infectious cause, or where a cancerous tumour is involved in the patch of hair loss (Watkins, 2010). Table 1 shows the main categories of alopecia.
| Non-cicatrical (non-scarring) | |
| Androgenic alopecia | Discussed in the article |
| Alopecia areata | There is no licensed treatment available in the UK. Alopecia areata is an autoimmune inflammatory disorder where cytokines are released from lymphocytes around hair follicles causing hair to be rejected. This includes alopecia totalis (all scalp hair lost) and alopecia universalis (all scalp and body hair lost, including eyelashes). |
| Telogen effluvium and anagen effluvium | Sudden hair loss can occur after childbirth, or severe stress or certain drugs (e.g. with chemotherapy or after radiotherapy). Hair usually grows back without medication (Watkins, 2010) |
| Traction alopecia (TA) | TA is related to bad hairstyling habits (e.g. tight braiding, hot tongs and chemical straighteners). Habits must change for recovery to take place (Rogers and Avram, 2008) |
| Tinea capitis (ringworm) | This is due to an underlying infectious cause by a dermatophyte fungus. Usually, Microsporum canis is passed on from an infected cat or dog. It responds to terbinafine or griseofulvin antifungals (Watkins, 2010; British Association of Dermatologists, 2017a) |
| Trichotillomania | Trichotillomania is self-inflicted hair loss traumatically induced from pulling out hairs. Underlying psychological issues are usually the cause |
| Primary cicatricial (scarring) | |
| Lichen planopilaris (LPP) | LPP has a lymphocytic inflammatory origin and needs strong anti-inflammatories such as corticosteroids or, failing that, tacrolimus, mycophenolate, doxycycline, hydroxychloroquine or ciclosporin. Biopsy of small areas for diagnosis. No licensed treatment (Watkins, 2010; British Association of Dermatologists, 2016) |
| Frontal fibrosing alopecia | As above; a variant of LPP affecting the frontal hairline (Watkins, 2010; British Association of Dermatologists, 2018) |
| Discoid lupus erythematosus | As per LPP (Watkins, 2010; British Association of Dermatologists, 2017b) |
| Folliculitis decalvans | Neutrophil inflammatory origin. Treatment must be aimed at the pathogenic organisms responsible, e.g. antibiotics, sometimes isotretinoin. The condition needs corticosteroids if severe. MC&S biopsy needed (Watkins, 2010; British Association of Dermatologists, 2015) |
| Folliculitis keloidalis | Hair loss is due to neutrophilic and lymphocytic inflammation, a mix of anti-inflammatories and antibiotics should be prescribed. Surgical or laser excision can improve the situation and/or a long course of antibiotics. Biopsy and microscopy, culture and sensitivity needed (Watkins, 2010) |
| Erosive pustular dermatosis | As above. Can be treated with 5-fluorouracil cream, imiquimod cream or diclofenac gel (Watkins, 2010) |
| Secondary cicatricial (scarring) | Trauma caused by a tumour, mechanical injury, burns, radiation and/or congenital alopecia (hypotrichosis); a condition whereby the individual is born without hair. Patients can opt for wigs or a hair transplant provided enough donor hair. Morphea (coup de sabre) is a rare localised scleroderma usually at the frontal scalp area, triggered by inflammatory disease. Treatments have included methotrexate, intralesional steroids or phototherapy (Watkins, 2010). |
Clinical diagnosis
To assist diagnosis, a robust model of medical consultation (e.g. the Calgary Cambridge model of consultation) must always be used (Kurtz et al, 2003). In particular, details of when, where and how the hair loss has occurred must be gathered. Many forms of alopecia can be clinically diagnosed; however, scarring forms need biopsies taken to confirm diagnosis. Consultations should be carried out using a dermatoscope and nails should always be checked (Rogers and Avram, 2008; Watkins, 2010). Other investigations include pull tests, wash tests, hair counts, immunoflourescence, microscopy, culture and sensitivity and blood tests to include vitamin D, iron and thyroxine androgen levels (Rogers and Avram, 2008).
Mentioning from the outset that no medical intervention is always an option for the hair loss sufferer is important, with self-acceptance core to this choice. Otherwise, hair replacement systems (wigs) are a popular camouflage and still available on the NHS. Referral to support groups (e.g. National Alopecia Foundation, Help4Alopecia and Alopecia UK) is always recommended. The Dermatology Quality of Life Index is useful for gauging the patient's psychological state (Messenger et al, 2012).
Furthermore, it should be stressed that all alopecias leave the scalp vulnerable to sun damage (e.g. development of solar keratoses) and are at a high risk of developing basal and squamous cell carcinomas or, sometimes, a malignant melanoma (Watkins, 2010). A thorough consultation should always cover the use of sunscreens, hats and wigs.
The role of androgens
Male pattern hair loss (MPHL) and female pattern hair loss (FPHL) are the most frequent form of alopecia in men and women. By the age of 70 or older, 80% of Caucasian men and up to 40% of Caucasian women show signs of it (Kanti et al, 2018). Both men and women have androgen hormones that are responsible for hair growth. Androgens are produced in the testes and adrenal glands in men, and in the ovaries and adrenal glands in women. Androgens are converted to oestrogen in women and testosterone in men. There are several types of androgens and conversions, the main ones being to dihydrotestosterone (DHT) and dihydroepiandrosterone (DHEA) (Brenner and Bergfield, 2003; Olsen et al, 2005; Rogers and Avram, 2008).
Thinning of scalp hair in men and women is a common presenting complaint (Brenner and Bergfield, 2003; Olsen et al, 2005). It is a genetically inherited sensitivity to the effects of DHT, the production of which is regulated by types I and II 5-alpha reductive enzymes (Brenner and Bergfield, 2003; Olsen et al, 2005; Rathnayake and Sinclair, 2010). The condition is characterised by the miniaturisation of terminal hairs on the scalp to vellus hairs; this is due to the shortening of the anagen phase of hair cycling (Olsen et al, 2005; Rathnayake and Sinclair, 2010). Vellus and terminal hairs are usually present under dermoscopy.
Diagnosing male pattern hair loss
MPHL can affect men from their mid-20s, starting in the bi-temporal and frontal scalp zones (receding hairline), followed by crown loss (Brenner and Bergfield, 2003; Olsen et al, 2005; Rathnayake and Sinclair, 2010). Male pattern baldness, an alternative name for AGA, can be classified according to the photographic Norwood Hamilton scale (Levels I–VII) and is shown in Figure 1 (Olsen et al, 2005; Rathnayake and Sinclair, 2010).
Hairs transform from thick terminal hairs to thin vellus hairs. Vellus hairs are thin, wispy and semi-transparent, with the follicle still present but no longer visible (Olsen et al, 2005; Rathnayake and Sinclair, 2010; Rogers and Avram, 2008). A proportion of these hairs can be brought back to terminal hairs with medical management alongside surgery (Kanti et al, 2018; Olsen et al, 2005; Rathnayake and Sinclair, 2010). The more treatment modalities employed, the better; using a combination of medical and regenerative techniques is ideal and every hair medication has side effects, associated costs, and compliance issues. Treatments include platelet-rich plasma (PRP), ACell, laser devices and camouflage techniques. It is also best to use a holistic approach (Olsen et al, 2005; Navarro et al, 2018; Rathnayake and Sinclair, 2010).
In young patients, there will be ongoing hair loss; hence, medications and non-invasive methods should be used, while surgery should be avoided (Gordon and Tosti, 2011; Kanti et al, 2018; Messenger et al, 2012). Patients in their 30s with an adequate donor hair supply should be counselled for medications and possibly surgery, discussing the advantages and disadvantages of this. Patients who are, for example, 65 years of age or over, with very good donor density (i.e enough to cover the area of hair loss) would be better surgical candidates although medications may also be used in combination (Kanti et al, 2018; Rogers and Avram, 2008; Rathnayake and Sinclair, 2010).
Diagnosing female pattern hair loss
FPHL is divided into stable and unstable loss. A thorough assessment should incorporate history, examination, biopsy (as needed) and possible referral to a dermatologist or endocrinologist (Tosti et al, 2009). In females over the age of 30, 30% experience hair loss. However, a clinician may need to search for an alternative cause, such as recent pregnancy, illness, trauma, general anaesthetic, chemicals, significant weight loss, fever, telogen effluvium (TE) or other cause. Thorough investigations are critical, as finding any of the above causes would preclude a patient from surgery and indicate medical optimisation (Tosti et al, 2009; Whiting, 1996).
Biochemistry tests should include thyroxine levels, erythrocyte sedimentation rate, iron levels, screening for autoimmune diseases, a history of metal allergy, dysmenorrhea, hormone profile, testosterone and whether the patient is having hormone replacement therapy. Hormonal problems will not prevent surgery, but mean that there is a need to optimise care in more ways than one, with, for example, hormone therapy, finasteride, minoxidil, light therapy and replacement medications (Tosti et al, 2009; Whiting, 1996).
FPHL is an alternative name for female androgenic alopecia, although its androgen dependency has not been clearly established (Olsen et al, 2005; van Zurren et al, 2012) it can be classified according to the photographic Ludwig scale (Levels I–III) or the Sinclair scale (Levels I–V) found in Figures 1 and 2. Generally, hair loss presents with thinning or a ‘Christmas tree’ pattern on the vertex of the scalp. For women, such hair loss may be associated with detectable hyperandrogenaemia, polycystic ovarian syndrome (PCOS), acne and hirsutism.
Prescribing options
Minoxidil 5%
Minoxidil has been licensed for AGA since its original US FDA approval in 1988. ‘Regaine’ is the UK proprietary name for minoxidil and is available over the counter but is not available on an NHS prescription. Initially, minoxidil was licensed to decrease blood pressure (a potassium channel-blocker) and is thought to work by helping blood flow to the hair follicles and by increasing follicular size and hair shaft diameter, thereby stimulating and prolonging hair growth (Rogers and Avram, 2008).
The most recent systematic literature review by the European Dermatology Forum (2018), regarding the efficacy of topical minoxidil, reported on 48 studies using the standards of the Appraisal of Guidelines for Research and Evaluation instrument (Kanti et al, 2018). This forum supersedes all other versions, some of which had been criticised by van Zuuren's 2012 Cochrane Systematic Review for relying on heavy consensus methodology, and that the ‘level of evidence’ in the guideline was based on the methodology quality of the trials as reported by the authors (van Zurren et al, 2012).
The review found the majority of the included studies provided high-quality evidence on the efficacy of topical 5% minoxidil. Oral minoxidil 5% was used in one study and found to only slightly increase the hair count compared to topical minoxidil 5% and, unfortunately, hair falls out if treatment is stopped. Men can use 5% minoxidil foam twice daily (Kanti et al, 2018).
Minoxidil 2% and 5%
The review included the results of 19 studies that investigated and found the efficacy of topical minoxidil in women. The efficacy of minoxidil 5% solution or foam applied daily was comparable to 2% applied twice daily. In the UK, topical minoxidil 2% is licensed for FPHL twice daily or 5% foam once daily (Kanti et al, 2018). Generally, minoxidil takes full effect in around 3–4 months but is best evaluated after a 12-month period. Patients should be warned that once the treatment is stopped, the hair falls out again within a few months. Other side effects include changes in hair colour and texture, as well as possible contact irritation. Furthermore, hirsutism has been a reported side effect in women (Kanti et al, 2018).
Finasteride
Finasteride is a 5-alpha-reductase inhibitor and works by blocking the production of testosterone to DHT to reduce serum DHT levels and protect the follicles that produce hair. Initially, finasteride was licensed by the FDA in 1992 to alleviate symptoms of benign prostatic hyperplasia (BPH) and then licensed for hair loss in 1997. Propecia 1 mg is the proprietary name for finasteride, and it is licensed in the UK for once-daily oral use in men with AGA; it is a prescription-only medication, but not available on the NHS. It works in around 3–6 months but, if stopped, the hair reverts to its previous state in 9–12 months. Reviews should be at 3–6 months, and then every 6–12 months (Rogers and Avram, 2008).
The previously mentioned 2018 review included 25 studies investigating the efficacy of oral finasteride in men. Long-term results up to 120 months were available (Kanti et al, 2018). Evidence was not conclusive that finasteride 1 mg daily is more effective than topical minoxidil 5% daily, but at 12 months it was more effective than twice daily use of minoxidil 2%. Combination therapy using minoxidil topical 5% solution and finasteride 1 mg worked more effectively together than single therapy. Sexual dysfunction in men is the most commonly reported side effect (Kanti et al, 2018). Furthermore, randomised control trials (RCT) are underway for the use of topical finasteride (Lee et al, 2018).
Finasteride is used off-licence in women and children, and is contraindicated in pregnant women and those of childbearing age, as it can cause birth defects and feminisation of the male fetus. No placebo-controlled trial results are available at present, even though efficacy studies have shown 5 mg daily may be effective in normoandrogenic and pre- and post-menopausal women (Kanti et al, 2018).
Dutasteride
Dutasteride is a type I and II 5-alpha-reductase inhibitor. Technically, it is licensed for moderate to severe symptoms of BPH (Rogers and Avram, 2008). The 2018 review found four out of five studies investigating its use in male AGA were placebo-controlled, providing high-quality evidence. Off-licence use of oral dutasteride 0.5 mg daily has been documented (e.g. with a loading dose daily for 2 weeks, then twice weekly). It should be considered only after use of finasteride 1 mg daily for 12 months has failed. While it reached Phase III stage trials for AGA in the US, the FDA halted proceedings due to side effects. As with finasteride, it should be avoided in women of childbearing potential and pregnant or breastfeeding women (Kanti et al, 2018).
Surgical options
Hair transplants (with or without combination treatment)
Donor dominance is the phenomenon that enables hair transplant surgery to work, and for its results to last. It refers to the fact that when hair from one part of the head that is not programmed for loss is transplanted to another part of the scalp or body, it retains its donor site properties, resulting in hair retention and ongoing growth; however, there are a few exceptions to this (Rousso and Presti, 2008).
Broadly, variants of hair transplant surgeries are categorised as strip follicular unit transplantation (FUT) or follicular unit extraction (FUE). In future, FUE may be better referred to as follicular unit excision due to the many thousands of incisions made for each treatment (Barrera, 2005; Rassman et al, 2017). Transplants are suitable for stable male AGA in patients over the age of 25 (Gordon and Tosti, 2011; Messenger et al, 2012; Kanti et al, 2018). Those with frontal and mid-frontal loss are the best candidates and these treatments can stop the continuing process of baldness in the areas treated (Barrera, 2005; Gordon and Tosti, 2011; Kanti et al, 2018). However, hair transplants are not currently available on the NHS.
FUT is where a strip of skin with follicular units is extracted and dissected into individual follicular unit grafts (Barrera, 2005), while FUE is where individual hairs are extracted manually or robotically. Furthermore, FUE and micropigmentation are becoming a popular combination treatment (Rassman et al, 2017).
Hair transplants are not always suitable for women due to rejection and are best where FPHL is medically controlled or spontaneously stabilised. FUT can be considered in female patients with sufficient donor hair and where no overlying diffuse TE is present. However, surgical side effects can include a TE 1–3 months post-operation. Treatment for those with body dysmorphic disorder or unrealistic expectations are contraindicated and cases should be evaluated 9–12 months after the procedure (Barrera, 2005; Rogers and Avram, 2008).
No RCTs have been undertaken to compare hair transplantation versus no hair transplantation, so only low-quality evidence is available for this treatment. Cohort and case studies comparing hair transplantation versus hair transplantation with supportive therapies exist, again with low-quality evidence. Minoxidil and finasteride can be used before and after hair transplants to stabilise the condition. Finasteride daily 1 mg with FUT may produce a better clinical outcome (Kanti et al, 2018).
Follicular unit extraction versus follicular unit transplantation
Surgeons prefer staged transplants to minimise ex vivo time, alongside use of all other regenerative techniques. Grafts are not trimmed. Any manipulation of the fragile adnexa can cause damage with this technique and so are advised for slightly larger sites to avoid damage to grafts. Transplants must be kept very moist (Rousso and Presti, 2008; Navarro et al, 2018).
Supply versus demand
There is an ever-increasing demand for hair due to ongoing loss and, thus, an ever-decreasing supply of graft tissue. Hence, the clinician needs to project hair demands 10–20 years down the line when consulting with a patient (Rousso and Presti, 2008).
Non-prescription and non-surgical options
Platelet-rich plasma, mesotherapy and low light laser therapy
PRP is an autologous preparation of platelets in concentrated plasma, the optimal concentration of which is unclear (Khatu et al, 2014). It is hypothesised that growth factors released from platelets may act on stem cells in the bulge area of the follicles, stimulating the development of new follicles and promoting neovascularisation (Khatu et al, 2014). While studies show PRP scalp injections to be a simple, cost-effective and feasible treatment option for MPHL and FPHL, the latest European guidelines highlight there is currently no standardised treatment technique but include two methodologically sound efficacy studies, although with low-grade evidence (Kanti et al, 2018).
Mesotherapy is a procedure whereby micro-injections are administered below the epidermal layer to reach targeted problem tissues (Rogers and Avram, 2008; Hairloss.org, 2019). However, mesotherapy is simply a technique and not a phenomenon exclusive for use in hair loss treatment (Kanti et al, 2018). Therefore, when evaluating mesotherapy as a hair loss treatment, it is actually the active ingredients topically injected into the scalp that are most important to consider in the process. Hair loss mesotherapy can be used on men or women and alone or in combination with other hair loss modalities, though there is a lack of evidence to suggest this effectiveness in combination (Kanti et al, 2018).
Amino acids, minerals, vitamins, co-enzymes and nucleic acids can be customised according to the unique needs and preferences of the patient. Commonly, biochanin A, a potent isoflavone, is injected since it modulates testosterone-to-DHT conversion (Kanti et al, 2018). Acetyl tetrapeptide-3 is another popular active ingredient used that stimulates anchoring proteins, as well as the extra-cellular matrix. Unfortunately, high-level evidence is lacking for mesotherapy hair loss treatments. European Guidelines do not make recommendations for or against various molecules, substances and interventions (Kanti et al, 2018).
Low light laser therapy was first used in 1967 and has its origins in biostimulatory processes known as ‘cold laser’ (Rogers and Avram, 2008). It appears to be safe on men and women, cost-effective and can be performed at home using a ‘laser comb’ device (Rogers and Avram, 2008; Avci et al, 2014; Kanti et al, 2018). The optimum wavelength, coherence and dosimetric parameters remain to be determined. Although some propose that it enhances adenosine triphosphate production by mitochondria, its exact mechanism of action is still not known (Rogers and Avram, 2008; Kanti et al, 2018). Others hypothesise that the stimulation of epidermal cells in the hair follicle bulge and shift the follicles into anagen stage (Avci et al, 2014). Currently, experts make no recommendations for or against treatment for longer than 6 months and there is a lack of evidence to suggest it is better used alone or in combination with other treatments. Furthermore, adverse events reported are usually mild, including scalp dryness, itching, tenderness and a warm sensation (Kanti et al, 2018).
Other medical treatments are also systematically appraised in the latest AGA European guidelines. They broadly conclude that there is a lack of evidence for the effectiveness of oral and topical hormones (e.g. antiandrogens spironolactone and cyproterone acetate, biologic drugs, vitamins, minerals and dietary supplements, including plant extracts) in reducing hair loss (Kanti et al, 2018).
Conclusion
In conclusion, practitioners must appreciate that alopecias are mostly chronic conditions. As a result, many sufferers turn to treatments that are not considered part of conventional medicine, and for which there is little to no evidence. These options are known as complementary and alternative medicine (CAM). Healthcare professionals need to be able to discuss CAM with patients. One of the main categories of CAM is traditional Chinese medicine (TCM), and includes treatments such as topically rubbing ginger into the scalp, brewing Chinese herbs to wash hair with and/or orally ingesting brewed herbs (van den Biggelaar, 2010; Leow and Lee, 2017).
Whole medical systems and mind-body medicine are two strands of CAM explored through a review of the literature by van den Biggelaar, and include homeopathy, hypnotherapy, psychotherapy, aromatherapy, onion juice, garlic gel, vitamin A, segmental scalp massage, acupuncture and transcranial magnetic stimulation (van den Biggelaar, 2010).
Aestheticians should not take for granted the complexities of diagnosing and treating hair loss, yet be reassured simple advice such as daily SPF, a referral to support groups and/or referring on to the appropriate practitioner helps in the process.