Application of the Basic and Specific Classification on Patterned Hair Loss in Indians

Abstract

Context:

Several classifications for pattern hair loss (PHL) have been used over the years. The Norwood-Hamilton classification for men and Ludwig's classification for women is used commonly, but they have their limitations.

Aims:

The objective of the following study is to evaluate the efficacy of the basic and specific (BASP) classification in Indian populations.

Subjects and Methods:

We used the BASP classification to classify the PHL in the patients visiting our out-patient department in the period from June 2012 to May 2013. 763 patients were classified out of which 313 were females and 450 were males.

Results:

The majority of the female patients were in the 3-5^th decade of life and in males were in 4-6^th decade.

Conclusions:

The BASP classification is, easily remembered, reproducible classification for the diagnosis and treatment for both male and female pattern alopecia.

INTRODUCTION

Pattern hair loss (PHL) is the most common type of hair loss in men. In females, it is less common. Through the years, several classifications have been proposed, but the Norwood-Hamilton classification for men and Ludwig's classification for women are the most commonly used systems. In 1951, Hamilton proposed the first systemic classification for PHL. He classified the patterns based on fronto-parietal, frontal recession and vertex thinning.[1] Norwood, in 1975, put an emphasis on vertex only classification as an addition to the Hamilton classification.[2] Savin introduced a classification based on pictorial depiction of hair density as derived from midline scalp width.[3] Olsen proposed assigning different designations to the areas of the scalp (temporal, frontal, mid and vertex) as they bald at different rates in different individuals.[4,5] In an article in 1977, Ludwig presented a separate classification for women emphasizing on the preservation of the frontal hairline despite the loss of hair on the top of the scalp.[6] For surgical purposes, Bouhanna created a multifactorial classification of certain parameters such as fixed distances from the face, scalp mobility and thickness and covering power of hair, which can be quantified and computerized.[7] However, all of these have limitations such as Norwood-Hamilton is difficult to memorize and female pattern hair loss (FPHL) in men cannot be classified by this and Ludwig's classification cannot be used to classify male pattern hair loss in females. In addition, most of these classifications were based on Caucasians subjects and not Asians as in comparison with Caucasian patients, Asian patients with androgenetic alopecia (AGA) have different types of hair loss and family histories which may alter the treatment response. There was considerable overlap in types IV, V and VI in the Norwood classification with the ‘a’ variants further confusing the picture.[8] Thus a common classification system for men and women, which is easy to memorize and can be used for all races is required.

In an article in 2000, Koo et al. from Korea, classified male pattern alopecia into six types based on the English alphabetical letter shape of the hair loss area.[9]

The basic and specific (BASP) classification was designed by Lee et al.[10] This included four basic types and two specific types [Figure 1]. The basic type represents the shape of the anterior hairline and the specific type represents the density of hair on the frontal and vertex area. The final type is the combination of the basic and the specific type.[10]

Figure 1.

Basic and specific classification

SUBJECTS AND METHODS

Patients were classified according to the pattern of hair loss as per BASP classification as mentioned below. The patients enrolled were those who visited the out-patient department and inpatients who complained of hair loss. A detailed history regarding some of the etiological factors was elicited.

Inclusion criteria

All those who were classified as having PHL.

Exclusion criteria

All those who had diffuse hair loss, alopecia areata, any infection or inflammation of the scalp and hair, any drugs affecting hair growth or under stress.

The patients who fitted into the inclusion criteria and had no exclusion criteria were enrolled into the study after taking consent. Personal, drug and family history was elicited. Digital photographs were taken in four views.

The BASP classification

The basic and the specific type were further divided into three to four grades. One basic type is selected depending on the pattern and graded according to the extent of hair loss with regards to the reference points. The specific type may be selected wherever applicable and graded.

Basic type

The shape of the anterior hairline is divided into four basic types: L, M, C and U.

L - Linear line (no hair loss)

M - Shape of the hairline resembles the alphabet M

C - Shape of the hairline resembles the alphabet C

U - Shape of the hairline resembles the alphabet U.

The reference points are:

• Original anterior hairline (anterior hairline at that time when baldness is not present)

• The top of the vertex (highest point on the posterior crown)

• The occipital protuberance.

Type L

“L” refers to linear line seen when there is no hair loss seen along the anterior border in the fronto-temporal region [Figure 2].

Figure 2.

Basic type L

Type M

Recession in the fronto-temporal hairline is more prominent than the mid-anterior hairline hence the hairline looks like the alphabet “M”.

Type M₀

The original hairline is preserved. No hair loss is seen.

Type M₁

Fronto-temporal recession is present but does not extend beyond the anterior one-third of the virtual line connecting the original hairline and the top of the vertex [Figure 3].

Figure 3.

Basic + specific M₁F₁

Type M₂

Fronto-temporal recession extends further but not beyond the middle-third of the virtual line.

Type M₃

Fronto-temporal recession extends further into the last one-third of the virtual line [Figure 4].

Figure 4.

Basic + specific type M₃F₃

Type C

Recession in the mid-anterior hairline is more prominent than the Fronto-temporal hairline. The entire anterior hairline regresses posteriorly in the shape of semi-circle resembling the letter “C”.

Type C₀

The original hairline is preserved.

Type C₁

The mid-anterior hairline recedes to the anterior 1/3^rd of the virtual line connecting the original hairline and the top of the vertex.

Type C₂

The mid-anterior hairline recedes to the middle 1/3^rd of the virtual line.

Type C₃

The mid-anterior hairline recedes to the posterior 1/3^rd of the virtual line.

Type U

The anterior hairline recedes posteriorly beyond the vertex forming a horseshoe shape resembling the letter “U”. It is the most severe type of AGA.

Type U₁

The anterior hairline recedes to lie within the superior 1/3^rd of the virtual line connecting vertex and the posterior occipital protuberance.

Type U₂

The anterior hairline recedes to lie within the middle 1/3^rd of the virtual line connecting vertex and the posterior occipital protuberance.

Type U₃

The anterior hairline recedes to lie within the inferior 1/3^rd of the virtual line connecting vertex and the posterior occipital protuberance.

Specific type

The specific type may be included whenever necessary. There are two specific types: F and V.

Type F

It represents a general decrease in the density of hair over the entire top of the scalp, regardless of the anterior hairline.

Type F₁

Thinning of the hair on the crown is perceptible (mild change) [Figures 3 and 5].

Figure 5.

Specific type F₁

Type F₂

Thinning of the hair on the crown is pronounced (moderate change).

Type F₃

The hair on the crown is very sparse or absent (severe change) [Figure 4].

Type V

The hair around the vertex is notably sparser.

Type V₁

Thinning of the hair around the vertex is perceptible (mild change).

Type V₂

Thinning of the hair around the vertex is pronounced (moderate change).

Type V₃

Thinning of the hair around the vertex is very sparse or absent (severe change).

RESULTS

The male patients were 450 and the number of female patients was 313. The majority of the patients were in the 3-5^th decade in females and 4-6^th decade in males [Table 1].

Table 1.

Age wise distribution of individual types

In men, majority (63%) were diagnosed with M type, with M₂ being most common (34%). One of the males was diagnosed with female pattern alopecia [Table 2].

Table 2.

Sex wise distribution of final type (males)

All women were diagnosed with F type with F₁ (87%) being most common and none of them were diagnosed with male pattern alopecia. As the age increased, the grading downgraded from F₁ to F₃.

Nearly 48% men gave a history of having similar hair loss on their paternal side of the family, 1% gave a history of having similar history on the maternal side of the family and 51% gave negative history of similar complaints.

Almost 42% women gave a history of similar complaints on the maternal side, none had similar complaints on the paternal side and 58% had no family history of similar complaints.

It was observed that the basic type of Hair loss had paternal inheritance and the specific type had maternal inheritance.

DISCUSSION

The study by Hong et al. conducted a comparative study consisting of eight dermatological specialists, 17 dermatological residents and 15 general physicians who classified PHL in 100 sets of photographs using both the BASP and Norwood-Hamilton classifications. They found that BASP classification not only distinguishes all kinds of hair loss patterns, but also has better reproducibility and repeatability than the Norwood-Hamilton classification.[11] The prevalence of FPHL (Ludwig grade >I) for all ages was 11.8%, increasing with advancing age.[12] The Asian Consensus Committee for AGA developed an algorithmic guideline, based on the BASP classification since the pre-existing classifications of AGA cannot easily classify the patterns of AGA that are more frequently seen in Asians.[13]

Limitations

When fronto-parietal and vertex regions of alopecia have become confluent, type F₂ and F₃ can be confused with type V.

The subjects were mostly out-patients so it is not indicative of the prevalence and the types of PHL in the general populations.