Hidradenitis suppurativa: infection, autoimmunity, or both?

Abstract

Hidradenitis suppurativa (HS) is a chronic inflammatory skin disease mainly affecting areas rich in apocrine glands. Clinically, is characterized by painful subcutaneous nodules and if left untreated to pus secretion, abscess and fistula formation. Its frequency is estimated to be 0.5–4% of the general population, affecting women more often. Pathogenesis of HS is still not clearly defined. It seems to be a combination of genetic factors with alterations in the skin microbiome. Furthermore, at tissue (i.e. skin) as well as at serum level, several inflammatory cytokines are upregulated. The most important of the latter are tumor necrosis factor (TNF), interleukin (IL)-1, IL-17, and IL-23. Adding another level of complexity, it has been suggested that keratinocytes might be intrinsically activated, contributing also to the observed inflammation. Interestingly, it has been noted that frequency of HS is increased in some autoimmune rheumatic diseases, such as spondyloarthropathies (SpA). Of note, both HS and SpA have relatively strong association with metabolic diseases and obesity implying that there are indeed some common underlying pathophysiological pathways. Although no specific microbe has been identified, alterations in the microbiome of the skin of these patients have been reported. Of note, microbes with a capability for biofilm formation are abundant. Treatment of HS among others, include antibiotics as well as biologic drugs targeting TNF and other cytokines and used for autoimmune rheumatic diseases. Herein, we review the current evidence on links between HS and autoimmune diseases and infectious diseases with a focus on epidemiology and pathophysiology.

Treatment strategies in axial spondyloarthritis: what, when and how?

“…Hidradenitis suppurativa is more commonly reported in patients with axSpA compared with the general population [ 76 ], while patients with hidradenitis suppurativa are at increased risk of developing AS [ 77 ]. Adalimumab has been approved for the treatment of hidradenitis suppurativa, while infliximab and drugs targeting IL-17 also appear to be promising therapeutic options [ 78 ].…”

Synovitis, acne, pustulosis, hyperostosis, and osteitis syndrome: review and update

“…[3][4][5] Skin lesions of SAPHO syndrome showed neutrophilic infiltration, 2 which indicate potential links with autoimmune conditions, microbiome alterations, and genetic factors, as in other neutrophilic dermatoses. 6 autoinflammatory origin was supported by the elevation of a series of proinflammatory cytokines, such as tumor necrosis factor (TNF)-α, interleukin (IL)-1, IL-8, IL-17, and IL-18. 12,13 The IL-23-helper T cell (Th)17 axis was also reported to be involved in SAPHO syndrome.…”

Hidradenitis Suppurativa in the Military

“…Tetracyclines are recommended as monotherapy for mild stages of HS. [17][18][19] Doxycycline is the most commonly used tetracycline in HS patients and has been demonstrated to penetrate Staphylococcus aureus biofilm in high enough concentrations to maintain its antibacterial activity. 20 Moreover, doxycycline, as with other tetracyclines, has a multitude of anti-inflammatory and immunomodulatory properties 21 and can reduce the production of IL-1, IL-6, tumor necrosis factor α, and IL-8; downregulate chemotaxis; and promote lipo-oxygenase, matrix metalloproteinase, and nuclear factor κB (NF-κB) signaling inhibition.…”

“…20 Moreover, doxycycline, as with other tetracyclines, has a multitude of anti-inflammatory and immunomodulatory properties 21 and can reduce the production of IL-1, IL-6, tumor necrosis factor α, and IL-8; downregulate chemotaxis; and promote lipo-oxygenase, matrix metalloproteinase, and nuclear factor κB (NF-κB) signaling inhibition. 17 Clindamycin is the only known agent that has been studied for topical treatment and utilization in milder cases of HS. 17,22 Systemic combination of clindamycin and rifampicin is the most studied, with well-established efficacy in managing HS.…”

“…17 Clindamycin is the only known agent that has been studied for topical treatment and utilization in milder cases of HS. 17,22 Systemic combination of clindamycin and rifampicin is the most studied, with well-established efficacy in managing HS. 17,23,24 Clindamycin has bacteriostatic activity toward both aerobic and anaerobic gram-positive bacteria by binding irreversibly to the 50S ribosomal subunit, thereby inhibiting bacterial protein synthesis.…”