Female pattern hair loss

Letter to the Editor

DEAR EDITOR: I am concerned by the statement by Professor Rodney Sinclair in his article Excessive scalp hair thinning in a middle-aged woman in the October 2012 issue of Medicine Today (pages 53 to 55) that androgen excess and/or androgen binding to hair follicle androgen receptors are important factors in the pathogenesis of this problem without any elaboration as to the common cause of this problem. Androgen excess in women is usually caused by stimulation of both ovarian and adrenal androgen secretion by hyperinsulinaemia secondary to insulin resistance. Hyperinsulinaemia also stimulates the enzyme 5α-reductase, which converts testosterone to dihydrotestosterone, the androgen active in causation of androgenic hair loss, hirsutism and acne. Every endocrinologist has seen many women with diabetes who have androgenic alopecia, particularly those of Asian or Middle-Eastern ethnicity. Androgenic alopecia in women is, therefore, an indication for glucose tolerance testing, preferably with insulin level determination, so that these women can have their early diabetes, impaired glucose tolerance and insulin resistance diagnosed at a stage when vascular disease and diabetes can be prevented. Professor Sinclair makes no mention of the antiandrogen flutamide, which is far more effective than finasteride, spironolactone and cyproterone acetate in clinical trials. Flutamide, off-label, is the only antiandrogen in my experience that results in 2 to 3 cm hair regrowth after six months therapy in women with Sinclair stages 3 and 4 alopecia. Cyproterone acetate aggravates insulin resistance and causes weight gain. Finasteride has been associated with the development of carcinoma of the breast in six men treated for prostatic cancer, and flutamide has been associated with two cases. I do not prescribe flutamide to women with a family history of breast cancer, and not to others until they have had a breast examination by their GP or, if appropriate, a mammogram.

WARREN KIDSON FRACP Endocrinologist at Sydney Endocrinology and Diabetes, Randwick, NSW.

REPLY: I would like to thank Dr Kidson for his helpful comments. Female pattern hair loss (FPHL) may be an indicator of polycystic ovary syndrome (PCOS), which is associated with insulin resistance and hypercholesterolaemia.[1] Even in the absence of PCOS, insulin resistance and hypercholesterolaemia are commonly associated with FPHL and we are currently investigating this association in our clinic. I am unable at this stage to accurately quantify the risk or provide guidance on the utility of screening for these condition. My failure to mention flutamide was deliberate. It is effective, but its use is complicated by the rare but serious association with liver toxicity.[2] That, combined with the association Dr Kidson refers to between flutamide and breast cancer in men, suggests its use is best reserved for the management of recalcitrant cases.

RODNEY SINCLAIR MB BS, FACD

Professor of Medicine (Dermatology) at The University of Melbourne, Epworth Specialist Centre, Richmond, Vic.

References 1. Green J, Sinclair R. Skin manifestations of polycystic ovary syndrome. In: Kovacs GT (ed). Polycystic ovary syndrome. Cambridge: Cambridge University Press; 2000. p 89. 2. Yazdabadi A, Sinclair R. Treatment of female pattern hair loss with the androgen receptor antagonist flutamide. Australas J Dermatol 2011; 52: 132-134.