Background. We aimed to determine whether MPV can be used as a marker for the activity and the severity index of alopesi areata (AA).

Method. The charts of 71 children who received a diagnosis of AA and 70 age and gender-matched healthy children were retrospectively evaluated. The severity of hair loss was classified as S1 ( < 25%), S2 (25-49%), S3 (50-74%), S4 (75-95%), S4b (96-99%) (according to the percent of the area involved), alopecia totalis (AT), and alopecia universalis (AU). In the laboratory tests, the results of the complete blood count, anti-nuclear antibody (ANA), thyroid function tests (TSH, free/total T4, free/total T3), and autoimmune thyroid antibodies [antithyroid peroxidase antibody (anti-TPO) and anti-thyroglobulin antibody (AT)] were recorded.

Results. A total of 141 cases including 61 (43.3%) males and 80 (56.7%) females were included. There was no statistically significant difference between the groups according to the mean age (p > 0.05). The MPV measurements were statistically significantly higher in the AA group (p < 0.01). There was no statistically significant difference between the types of AA according to the mean age, gender distribution, the presence of nail involvement, the presence of family history, and the presence of autoimmune disease (p > 0.05). There was no statistically significant difference between the severity of AA according to the mean age, gender distribution, the presence of nail involvement, the presence of family history, and the presence of autoimmune disease (p > 0.05).

Conclusion. MPV is helpful in assessing clinical activity in patients with AA. However, prospective studies involving more patients are needed to support our findings.

Keywords: alopecia areata, inflammation, mean platelet volume