While they overlap, senescent alopecia is a diffuse thinning all over the scalp, whereas FPHL is characterized by a specific pattern of hair miniaturization and widening of the central part line.
This is an acute, massive shedding of hair following an insult like chemotherapy, a much more dramatic and rapid event than the slow progression of FPHL.
CCCA is a scarring alopecia that starts on the vertex, distinguished by the permanent loss of follicular openings, which are preserved (but contain miniaturized hairs) in FPHL.
Diffuse AA is a more rapid and uniform thinning process that may be associated with exclamation point hairs, and lacks the classic "Christmas tree" pattern of FPHL.
FFA is a scarring alopecia defined by the progressive recession of the frontal and temporal hairlines, a different pattern of loss than the vertex thinning of FPHL.
Hair loss from hypothyroidism is a diffuse, non-patterned thinning associated with other systemic signs, and lacks the specific hair follicle miniaturization pattern of FPHL.
This can cause a diffuse thinning that can mimic FPHL, but it is distinguished by low serum ferritin levels and improvement with iron supplementation.
LPP is a scarring alopecia distinguished by prominent perifollicular erythema and scale around affected follicles, which are not features of FPHL.
TE is an acute, diffuse shedding event triggered by a stressor, where patients notice a dramatic increase in hair falling out, unlike the slow, insidious thinning of FPHL.
This is distinguished by a history of tight hairstyles and hair loss localized to the frontal and temporal hairlines where tension is applied.
