The Global Hidradenitis Suppurativa Atlas (GHiSA) Methodology: Combining Global Proportions in a Pooled Analysis.

INTRODUCTION: Data concerning the global burden of Hidradenitis Suppurativa (HS) are limited. Reported prevalence estimates vary between 0.0003% and 4.1%, and data from various geographical regions are still to be collected. Previously reported prevalence rates have been limited by the methodological approach and source of data. This has resulted in great heterogeneity as prevalence data from physician-diagnosed cases poorly match those of self-reported apparent HS disease. METHODS: The Global Hidradenitis Suppurativa Atlas (GHiSA) introduces an innovative approach to determine the global prevalence of HS. This approach involves using a previously validated questionnaire to screen apparently healthy adults accompanying a patient to a non-dermatological outpatient clinic visit in a hospital. The screening questionnaire (i.e., the index test) is combined with a subsequent physician-based in-person validation (i.e., the reference standard) of the participants who screen positive. Ten percent of the screen-negative participants are also clinically assessed to verify the diagnostic precision of the test. The local prevalence (pi) will be estimated from each country that submits the number of patients who are HS positive according to the index test and clinical examination (n), and the corresponding total number of observations (N). CONCLUSION: The GHiSA Global Prevalence studies are currently running simultaneously in 58 countries across six continents (Africa, Europe, Australia, North America, South America, and Asia). The goal of the combined global proportion is the generation of a single summary (i.e., proportional meta-analysis), which will be done after a logit transformation, and synthesized using a random-effects model. The novel standardization of the Global Prevalence studies conducted through GHiSA enables direct international comparisons, which were previously not possible due to substantial heterogeneity in past HS prevalence studies.

External Validation of the IHS4-55 in a European Antibiotic-Treated Hidradenitis Suppurativa Cohort.

BACKGROUND: Previously, a new dichotomous outcome was developed, calculated as 55% reduction in the International Hidradenitis Suppurativa 4 (IHS4-55) score. It was validated in datasets of adalimumab and placebo-treated HS patients. External validation is an important aspect of clinical outcomes. OBJECTIVES: We aimed to externally validate the novel dichotomous IHS4-55 in a non-biologic treated dataset of HS patients. METHODS: Data from a previously published European-wide prospective clinical study of antibiotic treatment of HS patients were used to assess the association of IHS4-55 achievement with individual reduction in inflammatory nodules, abscesses, and draining tunnels. Moreover, the associations between IHS4-55 positivity and achievement of the minimal clinically important differences (MCIDs) for Dermatology Life Quality Index (DLQI), Numerical Rating Scale (NRS) Pain, and NRS Pruritus were analyzed. RESULTS: Data were obtained from 283 individual patients, of which 36.4% (103/283) were treated with clindamycin and rifampicin and 63.6% (180/283) with tetracyclines for 12 weeks. Achievers of the IHS4-55 demonstrated a significant reduction the counts of inflammatory nodules, abscesses, and draining tunnels (all p < 0.001). Additionally, IHS4-55 achievers had an odds ratio for achieving the MCID of DLQI, NRS Pain, and NRS Pruritus of 2.16 (95% CI 1.28-3.65, p < 0.01), 1.79 (95% CI 1.10-2.91, p < 0.05), and 1.95 (95% CI 1.18-3.22, p < 0.01), respectively. CONCLUSIONS: This study shows the external validity of the novel IHS4-55 by demonstrating a significant association between IHS4-55 achievement and a reduction in inflammatory lesion counts as well as achievement of MCIDs for DLQI, NRS Pain, and NRS Pruritus in an antibiotic-treated cohort. These findings support the use of the IHS4-55 as a novel primary outcome measure in clinical trials.

Mammary Hidradenitis Suppurativa Lesions - A Suggestion for Phenotyping.

BACKGROUND: Hidradenitis suppurativa (HS) is an under-diagnosed chronic inflammatory skin disease of the pilosebaceous unit of apocrine gland-rich parts of the body. The mammary area is the fourth most HS-affected area and, as typical lesions include non-fluctuating nodules, abscesses, and tunnels/sinus tracts, mammary HS is often mistaken for other mammary "boils", such as sub-areolar and granulomatous non-lactating breast abscesses. Our objective was to present a spectrum of mammary HS lesions, explore a possible classification, and expose mammary HS as a possible differential diagnosis to non-lactational breast abscesses. METHODS: A cross-sectional study on current and newly-referred patients treated for HS affecting the mammary area. Anamnestic information, subjective outcome measures, and lesion counts including anatomical location were collected. Patients with similar morphologies were grouped, and characteristics for the groups were investigated. LIMITATIONS: We were not aware of the number of morphologies we would find, and as a result the study did not have sufficient power to show significant differences after correction for multiple testing. RESULTS: We found three morphologically different subtypes of mammary HS; the Sternal, the Frictional, and the Nodule types. These groups differed in anatomical lesion characteristics and other patient characteristics. Furthermore, we found a fourth Mixed type - a combination of the other three. CONCLUSION: Differential diagnosis between mammary HS and sub-areolar or granulomatous non-fluctuating non-lactating breast abscess is most easily performed by assessing the precise anatomical location of the lesion and determining if the mammary lesion is the only lesion present or if similar lesions exist in other HS-specific areas.

The efficacy and tolerability of tetracyclines and clindamycin plus rifampicin for the treatment of hidradenitis suppurativa: Results of a prospective European cohort study.

BACKGROUND: Tetracyclines and clindamycin plus rifampicin combination therapy are both considered first-line therapy in current hidradenitis suppurativa guidelines. However, evidence for their efficacy is drawn from small studies, often without validated outcomes. OBJECTIVE: To assess the 12-week efficacy of oral tetracyclines and a combination of clindamycin and rifampicin. METHODS: A prospective, international cohort study performed between October 2018 and August 2019. RESULTS: In total, 63.6% of the included 283 patients received oral tetracyclines, and 36.4% were treated with clindamycin and rifampicin. Both groups showed a significant decrease in International Hidradenitis Suppurativa Severity Score System from baseline (both P < .001). The Hidradenitis Suppurativa Clinical Response (HiSCR) was achieved in 40.1% and 48.2% of patients, respectively (P = .26). Patient characteristics or disease severity were not associated with the attainment of HiSCR or the minimal clinically important differences for the Dermatology Life Quality Index and pain. LIMITATIONS: Cohort study. Respectively, 23.9% and 19.4% of patients had to be excluded from the HiSCR analysis for the tetracycline and combination therapy group because of a low abscess and nodule count at baseline. CONCLUSION: This study shows significant efficacy of both tetracycline treatment and clindamycin and rifampicin combination therapy after 12 weeks in patients with hidradenitis suppurativa. No significant differences in efficacy were observed between the 2 treatments, regardless of disease severity.

Candida infections in patients with psoriasis and psoriatic arthritis treated with interleukin-17 inhibitors and their practical management.

INTRODUCTION: Interleukin 17A (IL-17A) is a pro-inflammatory cytokine produced by helper T cells (Th17) and other cells of the immune system and exerts pleiotropic effects on multiple cell lines. The role of IL-17 in the pathogenesis of numerous inflammatory disorders is well-documented. IL-17 activates signaling through the IL-17 receptor, which induces other proinflammatory cytokines, antimicrobial peptides, and neutrophil chemokines that are important for antifungal activity. EVIDENCE ACQUISITION: Healthy levels of IL-17 can protect the host against extracellular bacterial and fungal infections in mucous membranes and epithelia. IL-17 deficiency reduces control of certain infections, while excessive IL-17 can produce unwanted inflammatory effects. EVIDENCE SYNTHESIS: Although the efficacy of the therapeutic blockade of this cytokine has been proven in several autoimmune diseases such as psoriasis and psoriatic arthritis, this strategy could also exacerbate fungal infections in such patients. Therefore, a better understanding of IL-17-mediated immunity to Candida is necessary for the development of autoimmune therapeutics that maintain antifungal immunity. CONCLUSIONS: In this review, we include a study of the new anti-IL-17 biological agents (secukinumab, ixekizumab, and bromalizumab) used for moderate-to-severe psoriasis and psoriatic arthritis treatment in clinical practice, as well as pivotal trials with bimekizumab. We study the relationship of these biological agents and the appearance of candidiasis in its various clinical forms.

Can we clinically identify patients at risk of malignant transformation of skin tumors in Brooke-Spiegler syndrome?

Brooke-Spiegler syndrome (BSS) is a rare inherited autosomal dominant disease characterized by the development of multiple adnexal cutaneous neoplasms. BSS has been linked to mutations in CYLD gene, which is a tumor suppressor gene located on chromosome 16q12-q13. An increased risk of malignant transformation of adnexal cutaneous tumors in BSS patients has been reported. However, no reported genetic markers identify patients at risk of cutaneous malignancy. This study reviews published cases of BSS to investigate the role of clinical parameters as biomarkers of skin malignancy. A comprehensive review of the clinical aspects of BSS is based on 55 case reports. Our analysis revealed only age as a predictor of malignancy; however, this is also a general risk factor for development of malignancy and therefore of limited value as a screening tool. The study highlights the need for standardized clinical follow-up of patients.

Malassezia-Associated Skin Diseases, the Use of Diagnostics and Treatment.

Yeasts of the genus, Malassezia, formerly known as Pityrosporum, are lipophilic yeasts, which are a part of the normal skin flora (microbiome). Malassezia colonize the human skin after birth and must therefore, as commensals, be normally tolerated by the human immune system. The Malassezia yeasts also have a pathogenic potential where they can, under appropriate conditions, invade the stratum corneum and interact with the host immune system, both directly but also through chemical mediators. The species distribution on the skin and the pathogenetic potential of the yeast varies between different Malassezia related diseases such as head and neck dermatitis, seborrheic dermatitis, pityriasis versicolor, and Malassezia folliculitis. The diagnostic methods used to confirm the presence of Malassezia yeasts include direct microcopy, culture based methods (often a combination of morphological features of the isolate combined with biochemical test), molecular based methods such as Polymerase Chain Reaction techniques, and Matrix Assisted Laser Desorption/Ionization-Time Of Flight mass spectrometry and the chemical imprint method Raman spectroscopy. Skin diseases caused by Malassezia are usually treated with antifungal therapy and if there are associated inflammatory skin mechanisms this is often supplemented by anti-inflammatory therapy. The aim of this paper is to provide an overview of Malassezia related skin disease, diagnostic methods and treatment options.

A Hundred Years of Diagnosing Superficial Fungal Infections: Where Do We Come From, Where Are We Now and Where Would We Like To Go?

Superficial fungal infections have been known for hundreds of years. During the 20th century new diagnostic methods were developed and the taxonomy changed several times, which, unfortunately, resulted in many fungi having several names (synonyms). The taxonomy is important, as species-specific identification guides clinicians when choosing the most appropriate antifungal agent, and provides an indication of the source of infection (anthropophilic, zoophilic or geophilic). Traditional diagnostic tests (direct microscopy, culture and histopathology) are still widely used, but molecular-based methods, such as PCR, have many advantages, and increasingly supplement or replace conventional methods. Molecular-based methods provide detection of different genus/species spectra. This paper describes recent changes in dermatophyte taxonomy, and reviews the currently available diagnostics tools, focusing mainly on commercially available PCR test systems.

Psoriasis as a comorbidity of hidradenitis suppurativa.

BACKGROUND: Hidradenitis suppurativa (HS) and psoriasis (PSO) appear to share important pathogenic elements; in spite of this, the co-occurrence of the two has been widely unexplored. METHODS: To explore the co-occurrence of HS and PSO, we recorded the number of patients attending the outpatient clinic at the Department of Dermatology, Zealand University Hospital, Roskilde, Denmark, for the ICD10 diagnosis HS (DL73.2) or PSO (DL40.0, DL40.3, DL40.4, DL40.8, and DL40.9). Data were further compared with previously reported Danish national prevalence rates for HS and PSO. RESULTS: A total of 1,036 patients were included from the outpatient clinic: 440 HS, 624 PSO, and 28 with both diagnoses. In total 6.4% of HS patients had PSO, and 4.5% of PSO patients had HS. HS patients had OR = 2.99 (95% CI 2.04-4.38) of having PSO as compared to the background population. For PSO patients, they had OR = 2.56 (95% CI 1.74-3.77). DISCUSSION: We found a strong association between HS and PSO, which implies a possible comorbidity between PSO and HS that has not previously been properly elucidated. Such a connection could be a common inflammatory pathway driven by the increased secretion of IL-12/23 and TNFα that is a hallmark of both diseases.

Emerging Terbinafine Resistance in Trichophyton: Clinical Characteristics, Squalene Epoxidase Gene Mutations, and a Reliable EUCAST Method for Detection.

In recent years, cases involving terbinafine-resistant Trichophyton isolates have been reported increasingly, particularly in India. We present 14 cases of terbinafine treatment failure in Trichophyton-infected Danish patients due to acquired resistance. Patients infected with Trichophyton rubrum (n = 12) or Trichophyton interdigitale (n = 2) with elevated terbinafine MICs during 2013-2018 were included. Antifungal susceptibility testing (AFST) was performed following a modified EUCAST E.Def 9.3.1 method (5 days of incubation) with or without cycloheximide and chloramphenicol (CC) supplementation of the growth medium. The squalene epoxidase (SE) target gene was sequenced, and 3-dimensional enzyme homology modeling was performed. Most patients (12/14 [86%]) were male. The mean age was 53.5 years (range, 11 to 77 years). The mean duration of infections was 4.8 years at the time of resistance detection. Prior systemic terbinafine treatment was documented for all patients, and topical therapy for 62% (information was missing in one case). Overall, nine isolates (64%) displayed high terbinafine resistance (MICs, 4 to >8 mg/liter), while two (14%) displayed moderate (MICs, 1 to 2 mg/liter) and three (21%) displayed low (MICs, 0.125 to 0.25 mg/liter) terbinafine resistance compared with control isolates. MICs generated with or without CC supplementation were similar, but CC prevented contamination. Known and novel SE amino acid substitutions (F397L, L393F, L393S, F415S, H440Y F484Y, and I121M V237I) were detected in resistant but not control isolates. Three-dimensional homology modeling suggested a role of the novel I121M and V237I alterations. Terbinafine resistance has been detected in Denmark using a modified EUCAST method, which facilitated susceptibility testing of dermatophytes. Action is needed for this emerging public health problem.

Pediatric toxic epidermal necrolysis treated successfully with infliximab.

Successful management of toxic epidermal necrolysis (TEN) with tumor necrosis factor-α inhibitors has been described in adults. We present a case of a 7-year-old boy with infection-associated TEN, diagnosed by typical clinical and histopathological features, most likely caused by Mycoplasma pneumoniae. Treatment with a single dose of infliximab 5 mg/kg intravenously on day 5 after the onset of symptoms was followed by cessation of all blister formation over 3 days and complete resolution within a week. Sequelae were mild, consisting of postinflammatory hyperpigmentation and dry eyes.

The Follicular Skin Microbiome in Patients With Hidradenitis Suppurativa and Healthy Controls.

Importance: Although the pathogenesis of hidradenitis suppurativa (HS) remains enigmatic, several factors point to potential involvement of the cutaneous microbiome. Insight into the cutaneous microbiome in HS using next-generation sequencing may provide novel data on the microbiological diversity of the skin. Objective: To investigate the follicular skin microbiome in patients with HS and in healthy controls. Design, Setting, and Participants: This case-control study obtained punch biopsy specimens from patients with HS (lesional and nonlesional) and healthy controls between October 1, 2014, and August 1, 2016. Data were analyzed from March to November 2016. Patients with HS were recruited from the Department of Dermatology, Zealand University Hospital, Roskilde, Denmark. Biopsy specimens were analyzed at the Department of Microbiology and Infection Control, Statens Serum Institut, Copenhagen, Denmark. None of the participants received any antibiotics (systemic or topical therapy) within 1 month before the study. In patients with HS, biopsy specimens were obtained from lesional skin (axilla or groin) and nonlesional skin. Only nodules containing at least 1 visible hair follicle were biopsied. Biopsy specimens from healthy controls were obtained from the axilla only. Main Outcomes and Measures: The different microbiomes were investigated using next-generation sequencing targeting 16S and 18S ribosomal RNA. Results: The skin microbiome was characterized in 30 patients with HS (mean [SD] age, 46.9 [14.0] years; 19 [63% female]) and 24 healthy controls (mean [SD] age, 32.2 [12.0] years; 13 [54% female]). The next-generation sequencing data provided a previously unreported (to our knowledge) characterization of the skin microbiome in HS. The study demonstrated that the microbiome in HS differs significantly from that in healthy controls in lesional and nonlesional skin. Overall, the following 5 microbiome types were identified: Corynebacterium species (type I), Acinetobacter and Moraxella species (type II), Staphylococcus epidermidis (type III), Porphyromonas and Peptoniphilus species (type IV), and Propionibacterium acnes (type V). In lesional skin, microbiome types consisted predominantly of type I or type IV. Microbiome type IV was not detected in healthy controls. Several taxa, including Propionibacterium, showed a significantly higher relative abundance in healthy controls vs HS skin, indicating that Propionibacterium may be part of the pathogenesis in HS. Conclusions and Relevance: The study findings suggest a link between a dysbiotic cutaneous microbiome and HS.