Signs of Male Pattern Hair Loss
Male pattern hair loss presents with a highly reproducible pattern of hair thinning affecting the temples, vertex, and mid-frontal scalp, while temporal and occipital (back of head) follicles remain preserved. 1
Characteristic Distribution Pattern
The hallmark of male pattern hair loss is its predictable location:
- Hair loss occurs at the frontal hairline, temples, vertex (top of head), and crown 1
- The temporal and occipital (back and sides) regions remain unaffected, which distinguishes this from other types of hair loss 2
- The Hamilton-Norwood classification system is the standard tool used to describe the progression pattern 1
Physical Examination Findings
When examining the scalp, look for these specific signs:
- Hair follicle miniaturization - terminal (thick) hairs progressively become thinner and shorter, transforming into vellus-like (peach fuzz) hairs 2, 3
- Normal scalp appearance without inflammatory scaling - the scalp should not show redness, inflammation, or scarring 4
- Miniaturized hairs visible on dermoscopy - this is a hallmark finding that confirms the diagnosis 4
- Gradual, progressive thinning rather than sudden or patchy loss 5, 6
Clinical Presentation Timeline
- Affects 58% of men by age 50 and up to 80% of men by age 80 1, 3, 7
- Hair loss begins slowly and may become noticeable only after years of gradual loss 5
- The process involves shortening of the growth phase (anagen) and prolongation of the dormant phase (kenogen) 2
Key Distinguishing Features
Male pattern hair loss differs from other causes by:
- Preserved frontal hairline in early stages (though frontal recession occurs as it progresses) 5
- Absence of exclamation mark hairs (which are seen in alopecia areata) 8
- No patchy distribution - the pattern is predictable and symmetric 5
- Family history is often present - genetic factors play a major role 8, 3
Common Pitfalls to Avoid
- Do not confuse with alopecia areata, which presents with patchy, non-scarring hair loss and exclamation mark hairs 8
- Do not overlook other causes if the pattern is atypical, patchy, or involves scalp inflammation 5
- Consider other diagnoses if there is no family history of hair loss, as this makes male pattern hair loss less likely 5