Alopecia areata - hyperactivity of the hypothalamic-pituitary-adrenal axis is a myth?

INTRODUCTION: Psychological stress is known to cause exacerbation of different skin pathologies including alopecia areata (AA). A hyperactivity of the hypothalamic-pituitary-adrenal axis (the HPA axis) in patients affected by AA (AA patients) was proposed to be a neuroendocrine response to stress. Still little is known about melanocyte-stimulating hormone (MSH) and cortisol production in AA settings.

AIM: The aim of the study was to compare trends in a production of MSH and cortisol in patients with AA patients and healthy controls.

MATERIAL AND METHODS: Plasma concentrations of free cortisol and MSH were measured in 43 AA patients (35.5 ± 10.6 years) and 37 healthy subjects (35.9 ± 10.5 years) selected from the Dermatology Outpatient Clinic at Medical University of Silesia in Katowice, Poland. Results were submitted to statistical analysis with Shapiro-Wilk W-test and subsequently nonparametric (Mann-Whitney U-test) or parametric (Student's t-test) statistics were performed.

RESULTS: Mean plasma level of MSH was 5.39 ng/mL in AA patients and 5.71 ng/mL in healthy controls. The difference between groups was non-significant (P = 0.435), but the control group manifested higher values of MSH (Q75 = 13.6 ng/mL vs Q75 = 5.98 ng/mL) and this tendency was especially stronger in females. AA patients had greater mean plasma level of cortisol (157.63 ± 91.16 µg/L) than healthy controls (123.32 ± 71.28 µg/L); however, the difference between them was also non-significant (P = 0.063). No sex-dependent tendency to a greater production of cortisol was found.

CONCLUSIONS: Expectations of disturbances in production of MSH and cortisol were not fulfilled. Neither MSH nor cortisol plasma levels appear to be clearly changed in AA patients.