Focal atrichia: A diagnostic clue in female pattern hair loss

Focal atrichia is a common clinical finding in female pattern hair loss, the specificity and histologic findings of which need further clarification.

To determine the frequency of focal atrichia in various types of hair loss and its histologic characteristics in female pattern hair loss.

Part 1 of the study was a review of 250 consecutive female patients seen with hair loss for the presence of focal atrichia, and part 2 examined paired biopsy specimens from haired areas versus those from areas with focal atrichia in 18 subjects with female pattern hair loss.

Focal atrichia was seen in 46 of 104 of women with female pattern hair loss (44%), including 67% of those with the late-onset subtype versus 15% of those with the early-onset subtype, compared with in 3 of 146 of those with other hair disorders (2%). Biopsy findings of focal atrichia in female pattern hair loss showed primarily a more progressive miniaturization process than that of haired areas of the scalp.

Some women with female pattern hair loss may have had concomitant chronic telogen effluvium.

When present, focal atrichia is a clinical clue to the diagnosis of female pattern hair loss, particularly the late-onset subtype.