What are the stages of Male Pattern Hair Loss (MPHL)?

From the Guidelines

Male Pattern Hair Loss (MPHL) is characterized by a highly reproducible pattern of hair loss, preferentially affecting the temples, vertex, and mid-frontal scalp, and is typically classified using the Hamilton-Norwood classification system. The stages of MPHL can be described as follows:

• Stage 1: Minimal hair loss with a slight recession at the temples
• Stage 2: The hairline recedes further, forming an M, U, or V shape
• Stage 3: Deeper recession at the temples, considered the first stage of clinical baldness
• Stage 4: More extensive hair loss with a larger bald spot on the crown and greater recession at the front
• Stage 5: The band of hair between the crown and front becomes narrower with more pronounced balding in both areas
• Stage 6: The bridge of hair connecting the sides disappears as the bald areas join together
• Stage 7: The most advanced stage, with only a horseshoe-shaped band of hair remaining around the sides and back of the head, as described in the context of androgenetic alopecia (AGA) 1. MPHL occurs due to a genetic sensitivity to dihydrotestosterone (DHT), which causes hair follicles to shrink over time, producing progressively thinner hairs until they eventually stop growing altogether, affecting 58% of men by age 50 1.

From the Research

Stages of Male Pattern Hair Loss (MPHL)

The stages of MPHL can be understood through various classifications and studies on the condition.

• The Hamilton-Norwood classification system is commonly used to describe patterns of hair loss in men 2.
• The BASP classification is a new, universal, and accurate standard for both male and female pattern hair loss, which includes basic types (L, M, C, and U) and specific types (F and V) 2.
• MPHL is characterized by hair follicle miniaturization, where terminal hair follicles become dimensionally smaller, resulting in the production of thinner and shorter hair fibers 3.
• The condition progresses slowly, with hair loss occurring from the front, vertex, and crown, while temporal and occipital follicles remain 3.

Classification and Progression

• The BASP classification system provides a stepwise, systematic, and universal classification for pattern hair loss, regardless of sex 2.
• MPHL can be classified into different patterns, including diffuse thinning over the top of the scalp and little recession of the frontal hairline 2.
• The progression of MPHL is influenced by genetic factors, androgen metabolism, and other pathogenic factors such as microbiomata, oxidative stress, and microinflammation 4.
• The aim of therapy is to retard the progression of hair thinning and increase hair coverage of the scalp, with oral finasteride and topical solution of minoxidil being two FDA-approved drugs for this purpose 4.

Diagnosis and Treatment

• An ideal classification with high detail, practicality, and reproducibility is required to accurately diagnose and monitor MPHL 5.
• Numerous classifications have been invented, but a new classification that balances detail, practicality, and reproducibility is required to avoid confusion among clinicians 5.
• Treatment options for MPHL include finasteride 1 mg daily, dutasteride 0.5 mg daily, and topical 5% minoxidil twice daily, as recommended by guidelines for the diagnosis and treatment of MPHL 6.