To the Editor-The article "Is Polycystic Ovary Syndrome a Predisposing Factor for Pilonidal Sinus Disease?" by Ugurlu et al piqued our interest. This article highlights a novel finding of an increased risk of pilonidal sinus (PS) among women with polycystic ovary syndrome (PCOS; 22.5%) compared to the control group (1.7%). 1 This article seems to support the Karydakis theory of pilonidal sinus pathogenesis. However, recently there have been a few articles that challenge this notion. According to this theory, soft and macerated hair increases the incidence of PS disease (PSD). As a result, clinicians have started attributing excess sweating and body hygiene as some of the risk factors increasing the incidence of PSD. However, a recent study by Doll et al, in which 100 patients with PS were matched with 100 healthy patients, showed reduced sweating (18.4 ± 1.6 vs 24.2 ± 2.1 µL; p = 0.03). 2 Another study found no correlation between increased fecal and urine contact on the incidence of PS. 3 The article suggests that hirsutism, a clinical manifestation of hyperandrogenism that is common among patients with PCOS, may be linked to PS. However, the Rotterdam consensus used for the diagnosis of PCOS includes anovulatory and polycystic ovaries in the absence of hyperandrogenism as a type of polycystic ovary. 4 This criterion contradicts the authors' line of reasoning. The authors should look into how often and what kind of PS is there in people with different types of PCOS to better understand the risk factors for PS in this group.