Microbiology of hidradenitis suppurativa (acne inversa): a histological study of 27 patients

Abstract

Hidradenitis suppurativa (acne inverse) (HS) is a chronic skin disease primarily affecting hair follicles. The aetiology of HS is unknown, but infection is believed to play some role. This retrospective study investigated the microbial colonization directly in skin appendices in HS skin samples. Archival samples from 27 patients with HS were screened by immunofluorescence labelling with monoclonal and polyclonal antibodies against Gram-positive bacteria, Propionibacterium acnes and Propionibacterium granulosum. Fluorescence in situ hybridization was used for further species identification of Staphylococcus spp. Overall, 17 patients (63%) were found positive for bacterial colonization. Of these, 15 showed colonization in hair follicles and/or sinus tracts. The most commonly identified bacteria were DAPI labelled coccoids that were seen in 71% of the positive patients in the form of biofilms and microcolonies. P. acnes was found as biofilms in hair follicles of two patients. Staphylococcus aureus and coagulase-negative staphylococci were not detected in any sample. The results of this study indicate a common bacterial presence in HS skin lesions. Bacterial biofilms are not uncommon and their pathogenic role needs further evaluation.

Medical and Surgical Treatment of Hidradenitis Suppurativa: A Review

“…Some studies, usually circumventing the risk of contamination by aspirating pus from deep parts or by vaporization level by level with CO 2 laser showed that coagulase-negative staphylococci and anaerobic bacteria were the main bacteria recovered from HS lesions [56,57,58]. Therefore, bacterial infection is considered to be implicated in the secondary pathogenesis of HS, and since patients with HS often require long courses of antibiotics with only partial improvement in their skin, it seems likely that HS is a biofilm disease [59,60,61,62]. Biofilms are specialized communities of bacteria showing irreversible binding to external substrates through secretion of a sticky polysaccharide matrix that surrounds and protects the community from outside insults, including antibiotics [62].…”

“…Biofilms are specialized communities of bacteria showing irreversible binding to external substrates through secretion of a sticky polysaccharide matrix that surrounds and protects the community from outside insults, including antibiotics [62]. Biofilms adherent to sinus tract epithelium and hair follicles have been reported in HS, supporting the hypothesis that biofilms may play a secondary role in the pathogenesis of HS, thereby making bacterial eradication more difficult [60,61]. Although this concept is very fascinating and promising, more research efforts are needed to clarify its role in HS pathogenesis.…”

Leukocyte Profile in Peripheral Blood and Neutrophil-Lymphocyte Ratio in Hidradenitis Suppurativa: A Comparative Cross-Sectional Study of 462 Cases

“…Although studies point to an initial sterile process, a broad spectrum of bacteria have been found in mature HS lesions [16,17,18,19,20,21,22]. Significant bacterial infections may influence the levels of immature neutrophils in peripheral blood, and chronic bacterial infection is mostly not accompanied by increased neutrophils.…”

Update on Hidradenitis Suppurativa (Part I): Epidemiology, Pathogenesis, Severity assessment and Comorbidities

“…56 A retrospective study of 27 patients using histopathology found biofilm-like structures in one-fifth of the samples. 59 It is also possible that chronic HS lesions may resemble an environment such as one produced by a foreign body promoting and maintaining bacterial growth. 56 No yeasts or other infectious agents were found to play an important role in the pathogenesis.…”

“…56 Whether bacterial colonization is a primary or a secondary event of an initially sterile process is still a subject of much debate. 56,59 8. COMORBIDITIES As a chronic inflammatory dermatosis, HS is associated with a variety of concomitant and secondary diseases.…”