Pilonidal sinus disease: an intergluteal localization of hidradenitis suppurativa/acne inversa: a cross‐sectional study among 2465 patients

Abstract

Summary Background Hidradenitis suppurativa (HS), also referred to as acne inversa, is a debilitating skin disease characterized by inflammatory nodules, chronic abscesses and tunnels (fistulae and sinuses). The association with pilonidal sinus disease (PSD) is frequently reported but not well documented. Objectives To determine the prevalence and characteristics of inflammatory skin lesions located in the intergluteal fold (IGF) of patients with HS. Methods This was an international multicentre retrospective cross‐sectional study based on data collection from a large cohort of patients with HS with and without histopathology. Results From a total of 2465 patients with HS included in the study, 661 (27%) reported lesions in the IGF. These patients were significantly more often smokers and had more severe HS. Of the 238 patients with an available clinical diagnosis, intergluteal‐HS (IG‐HS) was diagnosed in 52 patients (22%) and PSD was diagnosed in 186 patients (78%). IG‐HS was associated with the localization of HS in the proximity of the IGF, including the buttocks, genitals and the anus. There was a possibility of misclassification bias in this study as a clinical/image‐based diagnosis or histopathology of the IGF lesions was not always available. Conclusions The high prevalence of PSD suggests a strong link between both entities. Therefore, it may be useful to identify common pathophysiological mechanisms and develop common therapeutic strategies. What's already known about this topic? The occurrence of pilonidal sinus disease has not been clearly reported among patients with hidradenitis suppurativa/acne inversa. What does this study add? This is the first study that investigated the prevalence of pilonidal sinus disease among a large cohort of patients and identified the patient characteristics. Risk factors that might help to improve the management of patients were identified.

Low dose of isotretinoin: A comprehensive review

“…Huang and Kirchhof () noted in their study noted that 68.0% (17/25) of their patients with mild‐to‐moderate HS treated on low‐dose isotretinoin (0.45 mg kg –1 day –1 for 6.8 months) showed partial response, and 53.0% (9/17) of them showed complete response, particularly, with those with lower weight, female gender, and those associated with acne. Benhadou et al () found that the prevalence of pilonidal cyst was around 20% in their studied patients with HS. Patients who have history of pilonidal cyst will benefit from isotretinoin (Patel et al, ).…”

Pilonidal Disease

“…Their sonographic characteristics are also similar and accordingly PD might be a variant of localized form of hidradenitis suppurativa. Their histology is somewhat different, although histology finding cannot be always helpful in distinguishing PD from hidradenitis suppurativa [10].…”

Into the (gluteal) fold: pilonidal disease and hidradenitis suppurativa – association or continuum?

“…The next stage is comparative histology, lesional inflammatory mediators and prospective clinical studies in order to validate the work of Benhadou et al . Such work should be encouraged not just in PSD, but also in DCS and AC, where the possibility of common inflammatory and mechanistic pathways may lead to increasing nonsurgical treatment options for patients and a better understanding of these debilitating inflammatory dermatoses.…”

“…In this issue, Benhadou et al . provide the initial epidemiological evidence required to reconsider PSD as within the spectrum of inflammatory dermatoses related to HS.…”

“…The clinical and histological diagnosis of PSD/HS, as Benhadou et al . have discussed, is inherently prone to diagnostic and confirmation bias . The same intergluteal lesion, in the hands of a surgeon or a dermatologist may be called PSD or HS, respectively.…”