Atopic dermatitis and psoriasis have traditionally been considered distinct inflammatory skin diseases with unique pathogenic mechanisms. However, accumulating evidence suggests significant overlap in their immunological pathways, metabolic features, and microbiome characteristics, challenging this conventional dichotomy. This review comprehensively examines the complex relationship between psoriasis and atopic dermatitis, with particular emphasis on their shared and distinct pathogenic mechanisms. We analyze the immunological networks, metabolic pathways, and microbial factors contributing to their development and progression. The review expands upon the disease spectrum hypothesis and discusses the nomenclature for conditions exhibiting features of both diseases. We critically evaluate the clinical and histopathological characteristics of concomitant psoriasis and atopic dermatitis, highlighting recent advances in molecular diagnostics for accurate disease differentiation. Importantly, we propose standardized diagnostic criteria for psoriasis dermatitis and examine current therapeutic strategies for managing overlapping conditions. Recent developments in targeted therapies and their implications for treatment selection are thoroughly discussed. By synthesizing current evidence and identifying knowledge gaps, this review provides insights into the complex interplay between psoriasis and atopic dermatitis, aiming to guide clinical decision-making and future research directions in this evolving field.

Background: The prevalence and outcomes of coronavirus 2019 (COVID-19) among patients using glucocorticoids and immunosuppressants remain controversial. Aim: The study aims to investigate the impact of immunosuppressants especially glucocorticoids on patients in the Autoimmune Bullous Diseases Cohort of West China Hospital (AIBDWCH) during COVID-19. Methods: We conducted a cross-sectional survey from December 7, 2022, to February 8, 2023, using questionnaires administered either face-to-face or by phone. COVID-19 cases were classified as confirmed, probable, or suspected according to World Health Organization criteria. Patients were divided into Group A (confirmed and probable cases) and Group B (suspected and other cases). The impact of glucocorticoids and immunosuppressive agents on COVID-19 disease and progression was evaluated with logistic regression models. Results: This study included 111 patients with pemphigus. Overweight patients had a reduced risk of confirmed COVID-19 (odds ratio [OR] 0.35 [95 % CI 0.13 -0.97], p = 0.045). Patients treated with a medium dose of prednisone during the pandemic had a lower incidence of COVID-19 compared to those on low doses, though the difference was not statistically significant. No independent effects of age, sex, comorbidities, and therapies were observed. No significant differences were found in COVID-19 symptoms among different therapy groups. Conclusions: Treatment with immunosuppressants, particularly glucocorticoids at low -to -medium doses, did not elevate COVID-19 risk in pemphigus patients. Consistent outcomes across treatments confirm the safety of these therapies during the pandemic.

Background . The global impact of coronavirus 2019 (COVID‐19) has raised concerns about the management of psoriasis patients, especially among those using biologics. Methods . We conducted a survey‐based research among Omicron‐infected (confirmed, probable, and suspected ones) psoriasis patients in the department of dermatology, West China Hospital, Sichuan University, from January 9th to January 22nd, 2023. We collected demographic and clinical information (psoriasis‐ and COVID‐19‐related) and conducted statistics analysis. Results . Of the 240 patients enrolled, they were classified by the psoriatic treatment, as biologics ( n = 138), nonbiological systematic treatment ( n = 52), and topical treatment or without pharmacological treatment ( n = 50). This study showed the characteristics of Omicron‐related symptoms and cutaneous signs in patients. We observed that patients who received topical treatment or without pharmacological treatment had a lower risk of presenting with COVID‐19 symptoms in the fully adjusted logistic model (OR = 0.40, 95% CI: 0.18–0.90, and P = 0.025). Moreover, in the model for skin manifestations, nonbiological systematic treatment (OR = 2.15, 95% CI: 1.08–4.27, and P = 0.029) and high BMI (OR = 1.10, 95% CI: 1.00–1.20, and P = 0.042) were correlative factors. Conclusions . Our data suggested that differential psoriatic treatment might be a correlative factor in developing symptomatic or asymptomatic Omicron infection and presenting cutaneous signs.

The utilization of biologics in patients with psoriasis with latent tuberculosis infection (LTBI) has garnered significant attention. Although the tuberculosis (TB) safety profile of second-generation biologics, including secukinumab, has been partially confirmed in both clinical trials and real-world studies, the necessity for prophylactic therapy in patients with LTBI prior to administering this class of biologics remains a topic of controversy. This study enrolled 62 patients with psoriasis with LTBI who underwent secukinumab with routine TB reexamination. Patients were divided into two groups based on whether they received antituberculosis therapy (ATB; n = 48) or not (NTB; n = 16). We performed a propensity score-matched (PSM) analysis between ATB and NTB subgroups and retrospectively reviewed their interferon-gamma release assays (IGRA) and radiographic results. No active TB case was reported on the basis of medical records and chest radiographs in either two group. Before PSM, the mean reexamining IGRA value was significantly elevated in patients who received prophylactic therapy (P = 0.00), but no significant increase was observed in patients who were not. After PSM, there was no significant IGRA value enhancement whether or not patients received prophylactic treatment. Our data provide additional information on the safety profile of secukinumab in patients with psoriasis with LTBI. Furthermore, our presentation of the reexamined IGRA results revealed no significant elevation in the ATB or NTB group. As such, we believe further exploration is necessary to determine whether anti-TB medication is required prior to administering secukinumab. In the past decade, biologics have revolutionized psoriasis treatment. Among patients receiving biologics, tuberculosis infection is a big concern. Secukinumab, an interleukin-17 inhibitor, belongs to the second-generation biologics. Clinical trials and real-life experience have partially reported its tuberculosis safety. In 2020, a systematic review of randomized clinical trials of secukinumab found no reactivate tuberculosis case. However, when participants tested positive for latent tuberculosis infection at screening in the clinical trials, they received antituberculosis treatment. Should patients with latent tuberculosis infection receive antituberculosis medication before receiving secukinumab? The answer is controversial and lacks evidence. This study enrolled patients with psoriasis with latent tuberculosis infection who underwent secukinumab with routine tuberculosis reexamination. Then, the patients were divided into two groups based on whether they received antituberculosis therapy and not. We observed that neither of these two groups presented tuberculosis activation cases. We also matched patients who received antituberculosis therapy and those who did not. The interferon-gamma release assay showed no significant increase after balancing the baseline. Our data indicated that secukinumab is safe among patients with latent tuberculosis infection even when they did not receive antituberculosis treatment.

Palmoplantar pustulosis (PPP) is a rare chronic pustular disease. Psoriatic arthritis (PsA) is one of the common manifestations of arthritis in PPP associated with a high burden of disease. The treatment of PPP is difficult and still in the exploratory stage. Only a few cases show that PPP complicated with arthritis have been successfully treated with janus kinase inhibition, interleukin (IL)-6 inhibitors, IL-12/23 inhibitors and tumor necrosis factor inhibitors. Here we reported that two patients were diagnosed as PPP with PsA and initially treated with IL-17 inhibitors. One case was only partially relieved, and the other case had severe paradoxical reaction in the trunk. The joint and skin condition of two patients had been significantly improved without reported adverse reactions after 18 weeks treatment with upadacitinib, which support upadacitinib may be a potential option for patients with PPP combined PsA.