Hidradenitis suppurativa; classification, remedies, etiology, and comorbidities; a narrative review

New-Onset Hidradenitis Suppurativa in Psoriasis Patients: A Multi-Center, Retrospective Cohort Study

BACKGROUND

Previous research has indicated a potential correlation between hidradenitis suppurativa (HS) and psoriasis (PSO), two chronic inflammatory dermatological diseases. However, there is a lack of comprehensive evaluations that consider a variety of clinical and demographic factors, and the risk of developing HS in PSO patients remains unclear. Our study aims to examine HS risk over time among PSO patients versus matched controls while considering the influence of confounders to provide insights into the potential link between these two diseases.

METHOD

In this multi-institutional cohort study using the TriNetX database, we matched 202,318 patients with PSO with an equivalent number of individuals without PSO, using propensity score matching. The study period extended from 1 January 2005 to 31 December 2018. We computed hazard ratios and their respective 95% confidence intervals (CIs) to evaluate the probability of HS manifestation over a period of 5 years in patients with PSO in comparison to those without PSO.

RESULTS

PSO patients demonstrated a consistently higher risk of developing HS than matched controls across all analytic models with the hazard ratios (HR) ranging from 1.43 (95% CI 1.30-1.56) to 5.91 (95% CI 2.49-14.04). Stratified analyses showed the increased HS risk was observed in both genders but only significant in those aged 18-64 years. Kaplan-Meier analysis indicated PSO patients had a higher cumulative probability of developing HS over time (HR 1.77, 95% CI 1.49-1.89).

CONCLUSIONS

PSO was associated with increased HS risk, highlighting the importance of considering HS as a potential comorbidity in PSO patients and may have implications for early detection, prevention, and management strategies for both conditions. Shared inflammatory pathways, genetic components, and skin dysbiosis may contribute. Further research should elucidate underlying mechanisms.

Diagnoseverzögerung, komorbide Hidradenitis suppurativa und die prognostische Bedeutung bakterieller Kulturen bei Folliculitis decalvans: eine Kohortenstudie

Hintergrund

Folliculitis decalvans (FD) ist eine primäre neutrophile vernarbende Alopezie, die häufig zu irreversiblem Haarverlust führt. Daten zu Epidemiologie, klinischen Merkmalen, Folgen und prognostischen Faktoren sind nur eingeschränkt verfügbar.

Ziel

Die Beurteilung einer Patientenkohorte mit FD sowie die Charakterisierung schwerer Krankheitsverläufe und prognostischer Faktoren, die eine Remission verhindern.

Patienten und Methoden

Diese retrospektive Kohortenstudie umfasste 192 Patienten, bei denen zwischen 2010 und 2020 an einem tertiären Zentrum eine FD diagnostiziert und die mindestens sechs Monate nachverfolgt wurden.

Ergebnisse

Die Diagnose wurde im Mittel um 22,2 (± 29,7) Monate verzögert gestellt. Komorbide Erkrankungen mit Okklusion der Haarfollikel waren häufig. In 45,6% der Fälle waren Bakterienkulturen positiv, am häufigsten mit Staphylococcus (S.) aureus. Schwere Krankheitsverläufe waren mit komorbider Hidradenitis suppurativa und positiver Bakterienkultur, insbesondere S. aureus, assoziiert. Bei 50,7% der Patienten kam es zu vollständiger Remission: Bei 32% innerhalb der ersten sechs Monate der Behandlung und bei 18,7% während der Nachkontrolle. Rezidive waren häufig. Negative Prognosefaktoren bezüglich der Remission waren jüngeres Alter und positive Bakterienkultur.

Schlussfolgerungen

Es besteht Bedarf hinsichtlich der Ausbildung von Dermatologen, um die Diagnoseverzögerung zu reduzieren. Das Screening von FD‐Patienten auf komorbide Hidradenitis suppurativa und Bakterienkulturen sind wichtig für die Behandlungsplanung.

Diagnostic delay, comorbid hidradenitis suppurativa and the prognostic value of bacterial culture in folliculitis decalvans: A cohort study

BACKGROUND

Folliculitis decalvans (FD) is a type of primary neutrophilic cicatricial alopecia often leading to irreversible hair loss. Data on its epidemiology, clinical features, outcomes, and prognostic factors are limited.

OBJECTIVE

To evaluate a cohort of patients with FD and identify characteristics of severe disease and prognostic factors which impede remission.

PATIENTS AND METHODS

This retrospective cohort study included 192 patients diagnosed with FD and followed for at least six months at a tertiary center between 2010 and 2020.

RESULTS

There was a diagnostic delay averaging 22.2 (± 29.7) months. Comorbid follicular occlusion disorders were common. Bacterial cultures were positive in 45.6% of the cases, with Staphylococcus (S.) aureus being the most common pathogen. Severe disease was associated with comorbid hidradenitis suppurativa and a positive bacterial culture, particularly S. aureus. 50.7% of patients experienced complete remission: 32% within the first six months of treatment and 18.7% later during follow-up. Relapses were frequent. Negative prognostic factors for achieving remission included younger age and a positive bacterial culture.

CONCLUSIONS

There is a need for the education of dermatologists to reduce the diagnostic delay. Screening FD patients for comorbid hidradenitis suppurativa and obtaining bacterial cultures is important for treatment planning.

The Role of FDG-PET in the Evaluation of Hidradenitis Suppurativa: A Systematic Review

Hidradenitis suppurativa (HS) is a chronic skin disorder characterized by nodules, comedones, and sinus tracts that often leave prominent scarring. In recent years, non-invasive imaging techniques have been used to assess the inflammatory activity, vascularization, and treatment response of lesions. Specifically, fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) scans may aid in identifying systemic inflammation in patients with HS, improving diagnosis. Inflamed hypermetabolic tissues exhibit a greater uptake of FDG due to increased glucose uptake and vascularity. A systematic review was conducted to summarize the utility of nuclear imaging techniques in the diagnosis and treatment follow-up of HS. PubMed, Scopus, and ScienceDirect databases were utilized for relevant articles discussing the utility of PET scans in managing HS. A total of 51 citations were identified in the initial search. Following the review of titles, abstracts, and duplicates, 43 articles were excluded, leaving a total of eight articles for analysis. Data were extracted from each article, encompassing the number of patients, imaging techniques employed, and final results. An analysis of the data demonstrated that FDG-PET showed evidence of identifying subclinical lesions of the disease, improving the visualization of HS, and providing an objective method of assessing severity.

Hidradenitis suppurativa and psoriasis: the odd couple

Psoriasis and hidradenitis suppurativa are chronic inflammatory skin diseases that can develop together, negatively impacting on the patient's quality of life. We aimed to review the most up-to-date information regarding the epidemiology, pathogenesis, clinical presentation and possible therapeutical choices in patients with both psoriasis and hidradenitis suppurativa, thus linking these two autoimmune and autoinflammatory conditions. A narrative review of articles dating from 2017 to 2022 has been performed using the PubMed database. We analyzed the case reports and case series found in the literature regarding patients who suffered from both psoriasis and HS. Psoriasis arose before hidradenitis suppurativa in the majority of cases, while only a minority of them had hidradenitis suppurativa before psoriasis. Interestingly, some patients suffered from paradoxical hidradenitis suppurativa following biological therapy administered to treat the already present psoriasis. Lastly, new biological drugs have been marketed with great success for the outcome of psoriasis, but similar progress did not happen for hidradenitis. Novel therapeutic approaches and lines of research are needed for the treatment of these pathologies, even if concomitant, in order to improve patient's quality of life.