Hidradenitis suppurativa (HS) is a chronic, inflammatory dermatosis characterized by an occurrence of nodules, abscesses, sinus tracks and scarring. Its pathogenesis is multifactorial and still not fully understood, therefore, current systemic therapies still remain a serious challenge. Increased levels of several proinflammatory cytokines have been reported in patients suffering from HS, therefore biologics appear as a new approach to therapy for this condition. Adalimumab is the only one internationally registered agent and should be considered first after the conventional therapies appear insufficient. The efficacy and safety profile of some preparations, like infliximab and etanercept was confirmed so far in randomized trials, but there are some new biologics which are still being evaluated and require more rigorous examination.

Inflammatory bowel disease (IBD) could be associated with several extra-intestinal manifestations (EIMs) involving musculoskeletal, hepatopancreatobiliary, ocular, renal, and pulmonary systems, as well as the skin. In the last years, hidradenitis suppurativa (HS) is acquiring an increasing interest. IBD, especially Crohn's disease (CD), is among the most reported associated diseases in HS patients. The aim of this paper is to give a brief overview of data showing a possible epidemiologic and pathogenetic association between IBD and HS. We performed a pooled-data analysis of four studies and pooled prevalence of HS in IBD patients was 12.8%, with a 95%CI of 11.7%-13.9%. HS was present in 17.3% of subjects with CD (95%CI: 15.5%-19.1%) and in 8.5% of UC patients (95%CI: 7.0%-9.9%). Some items, especially altered immune imbalance, are generally involved in IBD pathogenesis as well as invoked by HS. Smoking is one of the most relevant risk factors for both disorders, representing a predictor of their severity, despite, actually, there being a lack of studies analyzing a possible shared pathway. A role for inheritance in HS and CD pathogenesis has been supposed. Despite a genetic susceptibility having been demonstrated for both diseases, further studies are needed to investigate a genetic mutual route. Although the pathogenesis of IBD and HS is generally linked to alterations of the immune response, recent findings suggest a role for intestinal and skin microbiota, respectively. In detail, the frequent finding of Staphylococcus aureus and coagulase-negative staphylococci on HS cutaneous lesions suggests a bacterial involvement in disease pathogenesis. Moreover, microflora varies in the different cutaneous regions of the body and, consequently, two different profiles of HS patients have been identified on these bases. On the other hand, it is well-known that intestinal microbiota may be considered as "the explosive mixture" at the origin of IBD despite the exact relationship having not been completely clarified yet. A better comprehension of the role that some bacterial species play in the IBD pathogenesis may be essential to develop appropriate management strategies in the near future. A final point is represented by some similarities in the therapeutic management of HS and IBD, since they may be controlled by immunomodulatory drugs. In conclusion, an unregulated inflammation may cause the lesions typical of both HS and IBD, particularly when they coexist. However, this is still a largely unexplored field.

There have been reports of an association between Crohn's disease and hidradenitis suppurativa, a chronic, relapsing, inflammatory condition of the skin. We investigated features of hidradenitis suppurativa in patients with Crohn's disease by analyzing clinical data and performing a literature review.

We performed a retrospective study by using information from the Mount Sinai Medical Center database from 2003 through 2013; International Classification of Diseases, 9th Revision codes were used to identify patients who had both Crohn's disease and hidradenitis suppurativa. We identified a total of 18 patients with inflammatory bowel disease (15 with Crohn's disease, 3 with ulcerative colitis) and hidradenitis suppurativa. We also performed a systematic search for publications listed in PubMed through December 2013.

We identified 15 patients with Crohn's disease and hidradenitis suppurativa who met the inclusion criteria (11 women, 4 men). Nine patients were black, 5 were white, and 1 was Asian. Regions most affected by hidradenitis suppurativa included the axilla (53%), inguinal region (47%), and perianal region (73%). Seven patients had colonic Crohn's disease, and 8 had ileocolonic Crohn's disease; 10 patients had perianal disease. Fourteen patients received medical treatment for hidradenitis suppurativa and for Crohn's disease. Twelve patients were treated with tumor necrosis factor inhibitors for Crohn's disease (11 received infliximab and 4 received adalimumab). Nine patients required dose escalation; 11 responded to tumor necrosis factor inhibitors, and 8 required surgery. Four patients were treated with tumor necrosis factor inhibitors for hidradenitis suppurativa (all with infliximab). Three required a dose escalation; 4 responded to tumor necrosis factor inhibitors, and 3 required surgery.

Crohn's disease and hidradenitis suppurativa are severe inflammatory conditions that can develop in the same patient. They frequently require increased medical and surgical therapy.

Acne inversa (hidradenitis suppurativa) is a potentially severe and chronic inflammatory disease with a significant negative influence on the quality of life. Usually, lesions are located in the areas of skin folds and it is characterized by the presence of painful nodules and fistulas with a tendency to tissue fibrosis. Currently, it is suggested that follicular occlusion by infundibular hyperkeratosis plays a crucial role in pathogenesis and an occupation of apocrine sweat glands is a secondary phenomenon. Most often, it refers to men after puberty. This article tries to present the latest theory concerning the etiology of inverted acne and methods of its treatment. It also describes the most common errors in diagnostic and therapeutic procedures, which are mainly connected with repeated and long antibiotic therapy and not radical surgical treatment.

Hidradenitis suppurativa (HS) is a chronic inflammatory disorder of the intertriginous area. Patients with HS have several challenges to their quality of life and activities of everyday living, including malodor, purulent discharge, and discomfort. There is often a delay in diagnosis and appropriate treatment. The need for cosmetically acceptable local treatments and dressing application makes this disease an important challenge for wound care specialists. The choice of optimal treatment varies depending on the disease severity, expert knowledge, the availability of an interprofessional team, and patient factors.