Identifying and Classifying Hair Loss

By Dr Martin Wade / 09 Nov 2018

Dr Martin Wade presents his diagnosis algorithm to help aesthetic practitioners classify different types of hair loss

Hair loss and scalp conditions are common amongst aesthetic patients in the UK. Hair is an intrinsic part of who we are as a person and so it is not uncommon for patients to place a lot of value on their hair. The most prevalent types of hair loss are androgenetic alopecia, in the form of male pattern baldness (MPB) or female pattern hair loss (FPHL), alopecia areata and frontal fibrosing alopecia (FFA).1,2,3 Around 50% of men have some degree of MPB by age 501 and alopecia areata can affect up to 2% of the population at some stage of their life.2

This article presents my algorithm for identifying hair loss, aiming to provide practitioners with a structured approach to help their aesthetic patients deal with hair loss and to help them identify when they may need to refer to a specialist.

Utilising an algorithm

Due to the broad range of hair loss and scalp conditions that exist, diagnosing the underlying causes of hair loss can be complex. As a dermatologist who specialises in hair loss and scalp conditions, I have developed a hair loss algorithm to help aesthetic practitioners navigate diagnosing hair loss conditions in a more systematic manner (Figure 1). I find that this algorithm helps distinguish patterns and potential causes of hair loss, while enabling practitioners to identify when they can help their patients. It also proves useful to help recognise where practitioners may need to refer to someone who specialises in specific hair and scalp conditions.

Forms of hair loss

The first step in diagnosing hair loss is to take a thorough history, including the length of time that the hair loss has been present, and also whether any other scalp symptoms exist. Through examining the scalp, an experienced practitioner will be able to identify the forms of hair loss that may be present in aesthetic patients. A dermatoscope (a type of microscope used by dermatologists) or magnifier can aid in examining the scalp closely to identify inflammation on the scalp or the presence of miniaturisation of the hair shafts (which would suggest androgenetic alopecia). When examining the scalp, I am looking to identify the form of hair loss that is present and to classify it as either diffuse or patchy.


I categorise diffuse hair loss as an even reduction in hair density. I find that it is seen in patients with either androgenetic alopecia (patterned) or telogen effluvium (global), which are both explained below. Within diffuse hair loss, practitioners should look to identify if there is patterned hair loss or global hair loss.


Patterned hair loss, with thinning of hair on the vertex of the scalp, is seen in androgenetic alopecia, otherwise known as MPB or FPHL. In men, MPB is caused by androgens and genetics, hence its name androgenetic alopecia.1,4 Although all men and women have a tendency to develop thinning hair as they age, the causes in women can vary according to age, which can make the condition more complicated. If the onset is in the teens and 20s, then it is more likely to be related to hormones and genetics.4 Occurring after 60, researchers believe that the main cause is simply the ageing process.5 Women aged between 30-60 usually have hair loss due to a combination of genetics, hormone levels and other non-hormonal factors such as thyroid, iron status and nutrition.5 I find this is the most complex group to diagnose because of the combination of various elements contributing to the cause of hair loss.


Global hair loss is characterised by reduced hair density throughout the entire scalp, with the archetypical condition being telogen effluvium. Telogen effluvium is an alteration of the hair cycle, where there is an increase in the number of hairs entering the resting phase (telogen). In a normal scalp, usually 12% of the hairs are in the resting phase.6 If this number increases even up to 15% or 16%, then patients become aware of increased hair shedding. Acute telogen effluvium can involve a rapid onset and is often quite dramatic with a telogen count of up to 25% of hairs. It usually lasts for under three months and if the condition lasts longer than this, it tends to be an ongoing concern and is then called chronic telogen effluvium.6


Patchy hair loss is when discrete areas that contain no hair are interspersed amongst areas on the scalp with a normal hair density. It is common in patients with alopecia areata or those that have the scarring alopecias. The patchy forms of hair loss can be classified as either non-scarring or scarring.7


With non-scarring hair loss, alopecia areata is by far the most common. This usually presents as randomly occurring patches of hair loss affecting the scalp hair, but it can also affect eyebrows, eyelashes and men’s beards. A history of patchy hair loss with spontaneous regrowth usually confirms the diagnosis. Hair loss with this condition can be dramatic and it can lead to complete hair loss from the scalp, which is called alopecia areata totalis.7 The non-scarring patchy forms of hair loss can be further divided into non-inflamed or inflamed.

  • Non-inflamed forms: refers to the loss of hair without erythema, scaling or symptoms of itching or pain. The non-inflamed forms of patchy hair loss include alopecia areata and trichotillomania. With alopecia areata, there are well demarcated patches of hair loss that often have exclamation mark hairs, which is a pathognomonic sign. Exclamation mark hairs are short hairs that are broken off and are narrower as they become closer to the scalp.7
  • Inflamed forms: refers mainly to capitis, a fungal infection on the scalp. This is seen much more commonly in children but can occasionally occur in adults. Once again, erythema and scale are seen on the scalp and pustules can sometimes be present. If this process continues untreated it can begin to scar, destroying the hair follicles.8


The most commonly seen scarring alopecia is lichen planopilaris, where perifollicular erythema (redness) and perifollicular hyperkeratosis (roughness) present around the hair follicles. The centre of the patches is usually paler and shiny, taking on a scarred appearance as they are devoid of any remaining hair follicles.9 Discoid lupus erythematosus can also look similar to lichen planopilaris, however it usually presents as larger, more inflamed patches of hair loss. Folliculitis decalvans usually presents as a ‘boggy scalp’ where pustules are present and may be seen with associated crusting. Multiple hairs emerging from one follicular orifice is often seen in this condition and is called tufting or pili multigemini. Central centrifugal cicatricial alopecia (CCCA) is a unique condition, seen almost exclusively in black women and is manifest by an enlarging patch of scarring hair loss originating on the posterior to mid-vertex, expanding outwards.9 In clinic, I have also seen an increasing number of women present with FFA. This should be considered in women who are reporting hair loss from the frontal hairline. The classic signs are a receding hairline with redness around the hair follicles and also the presence of lonely hairs stranded in front of the receded frontal hairline. This pattern can extend down to the ears and usually also involves eyebrow loss, while being considered a variant of lichen planopilaris.9


The prospect of a patient complaining of hair loss can be overwhelming. There are many causes of hair loss and the treatment is certainly not the same for all conditions. Being able to take a methodical approach to at least categorising, if not diagnosing, the type of hair loss will allow aesthetic practitioners to know when they are able to manage the situation or when a referral to a specialist may be required. The hair loss algorithm I have presented should help with this task and can be used as a reference point. If a practitioner can’t personally help the patient, then it is vital they are able to recognise the problem and point them in the right direction of someone who can.

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