Exploring the Role of Gut Microbiota in Patients with Alopecia Areata.

Imbalances in gut microbiota reportedly contribute to the development of autoimmune diseases, but the association between the etiopathogenesis of alopecia areata (AA) and gut microbial dysbiosis remains unclear. This cross-sectional study was conducted to identify and compare the composition of the gut microbiome in patients affected by AA and those in a healthy control (HC) group, and to investigate possible bacterial biomarkers for the disease. Fecal samples were collected from 19 AA patients and 20 HCs to analyze the relationship with fecal bacteria. The three major genera constituting the gut microbiome of AA patients were Bacteroides, Blautia, and Faecalibacterium. The alpha diversity of the AA group was not statistically significant different from that of the HC group. However, bacterial community composition in the AA group was significantly different from that of HC group according to Jensen-Shannon dissimilarities. In patients with AA, we found an enriched presence of the genera Blautia and Eubacterium_g5 compared to the HC group (p < 0.05), whereas Bacteroides were less prevalent (p < 0.05). The gut microbiota of AA patients was distinct from those of the HC group. Our findings suggest a possible involvement of gut microbiota in in the as-yet-undefined pathogenesis of AA.

Estimating the burden of vitiligo: a systematic review and modelling study.

BACKGROUND: Vitiligo is a chronic autoimmune disease characterised by depigmented skin patches, which can pose substantial psychosocial challenges particularly in individuals with dark skin tones. Despite its impact on quality of life, there is an absence of standardised global epidemiological data. We sought to address this gap with the present study. METHODS: In this study we did a systematic review and modelling analysis to estimate the global, regional, and national prevalence and incidence of vitiligo. We did a comprehensive search of nine digital libraries (PubMed, Embase, Web of Science, Scientific Electronic Library Online, KCI Korean Journal Database, Russian Science Citation Index, Western Pacific Region Index Medicus, Informit, and Health Research and Development Information Network) from inception up to May 25, 2023. We included cross-sectional or cohort studies reporting the incidence rate or prevalence of vitiligo, or data from which incidence rate or prevalence could be calculated, in the general population of a country or area of a country. Summary estimate data were extracted. A main outcome was to estimate the worldwide, regional, and country-specific lifetime prevalence of vitiligo diagnosed by physicians or dermatologists among the general population and in adults and children (as per age groups defined in included studies). We used a Bayesian hierarchical linear mixed model to estimate prevalence, and calculated number of affected individuals using the UN population structure in 2022. In estimating lifetime prevalence, studies reporting point or period prevalence were excluded. Our other main outcome was to estimate incidence rates of vitiligo, but due to a small number of studies, the data on incidence were presented in a descriptive summary. This study was registered on PROSPERO, CRD42023390433. FINDINGS: Our search identified 22 192 records, of which 90 studies met our inclusion criteria. Of these studies, six focused on the incidence of vitiligo, 79 reported on the prevalence of vitiligo, and five provided data on both incidence and prevalence. 71 studies reported on lifetime prevalence. In the most recent years studied, incidence rates in the general population ranged from 24·7 cases (95% CI 24·3-25·2) per 100 000 person-years in South Korea in 2019, to 61·0 cases (60·6-61·4) in the USA in 2017. In individual studies, incidence rates showed an increasing trend over the periods studied. The global lifetime prevalence of vitiligo diagnosed by a physician or dermatologist was estimated at 0·36% (95% credible interval [CrI] 0·24-0·54) in the general population (28·5 million people [95% CrI 18·9-42·6]), 0·67% (0·43-1·07) in the adult population (37·1 million adults [23·9-58·9]), and 0·24% (0·16-0·37) in the child population (5·8 million children [3·8-8·9]). Vitiligo prevalence was higher in adults than in children across all regions. Central Europe and south Asia reported the highest prevalence (0·52% [0·28-1·07] and 0·52% [0·33-0·82], respectively, in the general population). INTERPRETATION: This study highlights the need for standardised epidemiological data collection globally to inform public health policies and improve vitiligo diagnosis and management. Emphasis on the impact on individuals with darker skin tones is crucial to reducing stigma and improving quality of life. Furthermore, our study highlights the need to conduct more research in regions and populations that have been historically under-represented, to effectively address the worldwide burden of vitiligo. FUNDING: None.

Bridging Molecular Mechanism and Clinical Practice in Vitiligo Treatment: An Updated Review.

BACKGROUND: Treatment of vitiligo seeks to achieve three goals: cessation of disease progression, regeneration of pigmentation, and prevention of recurrence. SUMMARY: Number of nonsurgical interventions are available that suppress the autoimmune response and regenerate the melanocytes from the reservoir: phototherapy including psoralen and ultraviolet A, narrowband ultraviolet B, and 308-nm excimer and 311-nm Titanium:Sapphire lasers; topical agents including topical calcineurin inhibitors, topical corticosteroids, and topical 5-fluorouracil; and systemic agents including corticosteorids, mycophenolate mofetil, cyclosporine, methotrexate, minocycline, afamelanotide, and antioxidants. In recent years, a great advance has been made in the understanding of pathogenesis of vitiligo, and JAK inhibitors are being investigated as a new treatment. Minimally invasive procedures such as fractional lasers or microneedling can help achieve the optimal treatment outcome when used properly. KEY MESSAGES: Our review describes various treatment modalities for vitiligo based on their molecular mechanism of action. Bridging the gap between molecular mechanisms and therapeutic options would be a valuable reference for physicians in clinical practice.

All-Cause and Cause-Specific Mortality among Patients with Vitiligo: A Nationwide Population-Based Study in Korea.

Vitiligo is a common autoimmune skin disorder; however, there is limited information about risks of mortality among patients with vitiligo. Therefore, we aimed to investigate the mortality in patients with vitiligo. A population-based cohort study was conducted using the data linkage of the National Health Insurance Service database and the National Death Registry. Patients with incident vitiligo were matched with sociodemographic factors-matched controls without vitiligo in a 1:5 ratio. All-cause and cause-specific mortalities were compared between patients with vitiligo and controls. In total, 107,424 patients with incident vitiligo and 537,120 matched controls were included. The mortality rates were 34.8 and 45.3 per 10,000 person-years in patients and controls, respectively. Patients with vitiligo showed a significantly lower risk of mortality (adjusted hazard ratio = 0.75, 95% confidence interval = 0.72-0.78). The cause-specific mortality from infectious diseases, oncologic diseases, hematologic diseases, endocrine diseases, neurologic diseases, cardiovascular diseases, respiratory diseases, and renal/urogenital disease was significantly lower in patients with vitiligo. Patients with vitiligo were associated with a lower risk of mortality, suggesting that vitiligo-associated autoimmunity might contribute to reduced morbidity and mortality.

Autoimmune and Autoinflammatory Connective Tissue Disorders Following COVID-19.

Importance: Multiple cases of autoimmune and autoinflammatory diseases after COVID-19 have been reported. However, their incidences and risks have rarely been quantified. Objective: To investigate the incidences and risks of autoimmune and autoinflammatory connective tissue disorders after COVID-19. Design, Setting, and Participants: This was a retrospective population-based study conducted between October 8, 2020, and December 31, 2021, that used nationwide data from the Korea Disease Control and Prevention Agency COVID-19 National Health Insurance Service cohort and included individuals who received a diagnosis of COVID-19 via polymerase chain reaction testing and a control group with no evidence of COVID-19 identified from National Health Insurance Service of Korea cohort. Data analysis was conducted from September 2022 to August 2023. Exposures: Receipt of diagnosis of COVID-19. Main Outcomes and Measures: The primary outcomes were the incidence and risk of autoimmune and autoinflammatory connective tissue disorders following COVID-19. A total of 32 covariates, including demographics, socioeconomic statuses, lifestyle factors, and comorbidity profiles, were balanced through inverse probability weighting. The incidences and risks of autoimmune and autoinflammatory connective tissue disorders were compared between the groups using multivariable Cox proportional hazard analyses. Results: A total of 354 527 individuals with COVID-19 (mean [SD] age, 52.24 [15.55] years; 179 041 women [50.50%]) and 6 134 940 controls (mean [SD] age, 52.05 [15.63] years; 3 074 573 women [50.12%]) were included. The risks of alopecia areata (adjusted hazard ratio [aHR], 1.12; 95% CI, 1.05-1.19), alopecia totalis (aHR, 1.74; 95% CI, 1.39-2.17), antineutrophil cytoplasmic antibody-associated vasculitis (aHR, 2.76; 95% CI, 1.64-4.65), Crohn disease (aHR, 1.68; 95% CI, 1.31-2.15), and sarcoidosis (aHR, 1.59; 95% CI, 1.00-2.52) were higher in the COVID-19 group. The risks of alopecia totalis, psoriasis, vitiligo, vasculitis, Crohn disease, ulcerative colitis, rheumatoid arthritis, adult-onset Still disease, Sjögren syndrome, ankylosing spondylitis, and sarcoidosis were associated with the severity of COVID-19. Conclusions and Relevance: In this retrospective cohort study, COVID-19 was associated with a substantial risk for autoimmune and autoinflammatory connective tissue disorders, indicating that long-term management of patients with COVID-19 should include evaluation for such disorders.

Autoimmune, Inflammatory, Atopic, Thyroid, and Psychiatric Outcomes of Offspring Born to Mothers With Alopecia Areata.

Importance: Alopecia areata (AA) is associated with diverse autoimmune and psychiatric disorders. However, an investigation on the long-term outcomes for offspring born to mothers diagnosed with AA is lacking. Objective: To investigate the risks for autoimmune, inflammatory, atopic, thyroid, and psychiatric outcomes of offspring born to mothers with AA. Design, Setting, and Participants: This retrospective population-based birth cohort study used the linked birth registration database with the Nationwide Health Insurance Service database of Korea. The participants included all newborns born to mothers with 3 or more visits with International Classification of Diseases, Tenth Revision code of L63 and 1:10 birth year, sex, insurance, income, and location of residence-matched control offspring born to mothers without AA during the years from 2003 to 2015. The analysis was conducted from July 2022 to January 2023. Exposure: Maternal AA. Main Outcomes and Measures: The occurrence of the following diseases was measured in newborns from birth to December 31, 2020: AA, alopecia totalis/universalis (AT/AU), vitiligo, psoriasis, inflammatory bowel disease, rheumatoid arthritis, atopic dermatitis, allergic rhinitis, asthma, hyperthyroidism, hypothyroidism, Graves disease, Hashimoto thyroiditis, attention-deficit hyperactivity disorder, mood disorder, and anxiety disorder. Multivariable Cox proportional hazard analyses were performed with the following covariates: birth year, age, insurance type, income level, location of residence, maternal age, mode of delivery, maternal history of atopic disorders, and autoimmune disorders. Results: In total, 67 364 offspring born to 46 352 mothers with AA and 673 640 controls born to 454 085 unaffected mothers were analyzed. The risk of AA (adjusted hazard ratio [aHR], 2.08; 95% CI, 1.88-2.30), AT/AU (aHR, 1.57; 95% CI, 1.18-2.08), vitiligo (aHR, 1.47; 95% CI, 1.32-1.63), atopic disorders (aHR, 1.07; 95% CI, 1.06-1.09), hypothyroidism (aHR, 1.14; 95% CI, 1.03-1.25), and psychiatric disorders (aHR, 1.15; 95% CI, 1.11-1.20) was significantly increased in offspring born to mothers with AA. Among them, 5088 born to mothers with AT/AU were at much greater risk for the development of AT/AU (aHR, 2.98; 95% CI, 1.48-6.00) and psychiatric disorders (aHR, 1.27; 95% CI, 1.12-1.44). Conclusions and Relevance: In this Korean retrospective population-based birth cohort study, maternal AA was associated with the development of autoimmune/inflammatory, atopic, thyroid, and psychiatric disorders in their offspring. Clinicians and parents need to be aware of the potential for these comorbidities to occur.

Risk of autoimmune skin and connective tissue disorders after mRNA-based COVID-19 vaccination.

BACKGROUND: Data on the association between the development of autoimmune diseases and COVID-19 vaccination are limited. OBJECTIVE: To investigate the incidence and risk of autoimmune connective tissue disorders following mRNA-based COVID-19 vaccination. METHODS: This nationwide population-based study was conducted in South Korea. Individuals who received vaccination between September 8, 2020-December 31, 2021, were identified. Historical prepandemic controls were matched for age and sex in 1:1 ratio. The incidence rate and risk of disease outcomes were compared. RESULTS: A total of 3,838,120 vaccinated individuals and 3,834,804 controls without evidence of COVID-19 were included. The risk of alopecia areata, alopecia totalis, primary cicatricial alopecia, psoriasis, vitiligo, anti-neutrophil cytoplasmic antibody-associated vasculitis, sarcoidosis, Behcet disease, Crohn disease, ulcerative colitis, rheumatoid arthritis, systemic lupus erythematosus, systemic sclerosis, Sjogren syndrome, ankylosing spondylitis, dermato/polymyositis, and bullous pemphigoid was not significantly higher in vaccinated individuals than in controls. The risk was comparable according to age, sex, type of mRNA-based vaccine, and cross-vaccination status. LIMITATIONS: Possible selection bias and residual confounders. CONCLUSION: These findings suggest that most autoimmune connective tissue disorders are not associated with a significant increase in risk. However, caution is necessary when interpreting results for rare outcomes due to limited statistical power.

Automated Mass Screening for Comorbidities of Vitiligo Using the National Health Insurance Database.

Although the study design for identifying specific disease associations using a health insurance database has been well-established, few studies explore unknown comorbidities. We conducted a series of automated case-control studies for all International Classification of Disease, Tenth Revision, Clinical Modification diagnostic codes (A01-Z99) using the Korean National Health Insurance database from 2007 to 2017 to reveal undiscovered disease associations of vitiligo. A total of 90,297 patients with vitiligo and 90,297 age- and sex-matched controls without vitiligo were included, and disease associations for 1,265 relevant diagnostic codes were screened. A meta-analysis of the individual ORs for each International Classification of Disease, Tenth Revision code was performed to identify the possibility of selection bias. Finally, the association with vitiligo was significantly increased in 45 diseases and decreased in 6 diseases. We not only reaffirmed the positive correlation between vitiligo and other autoimmune diseases but also observed associations with obsessive-compulsive disorder and melanoma. In contrast, femur fracture showed a negative correlation. In this study, we attempted an automated mass screening and suggested a possible selection bias. In the era of large-scale databases, a systematic and comprehensive approach might be needed.

Has the core outcome (domain) set for vitiligo been implemented? An updated systematic review on outcomes and outcome measures in vitiligo randomized clinical trials.

BACKGROUND: In 2015, a major achievement in vitiligo research was the development of an internationally agreed upon core outcome domain set for randomized clinical trials (RCTs). Three outcomes were identified as being essential: repigmentation, side-effects/harms and maintenance of gained repigmentation. Four items were further recommended for inclusion. The following recommendations then followed: repigmentation should be assessed by measuring the percentage of repigmentation in quartiles (0-25%, 26-50%, 51-79%, 80-100%) and cosmetic acceptability of the results should be assessed using the Vitiligo Noticeability Scale. OBJECTIVES: The primary objective of this study was to assess uptake of the core outcome domain set for RCTs in vitiligo. Secondary objectives were to update the systematic review on outcomes reported in vitiligo RCTs, and to assess whether repigmentation and cosmetic acceptability of the results were measured using the above-mentioned recommended scales. METHODS: We searched PubMed, Cochrane Library (CENTRAL and Systematic Reviews) and ClinicalTrials.gov for vitiligo RCTs between November 2009 and March 2021. Screening and data extraction were independently performed on title and summary by two researchers. All outcomes and outcome measures reported in eligible RCTs were retrieved and collated. RESULTS: In total, 174 RCTs were identified: 62 were published between 2009 and 2015, and 112 were published between 2016 and 2021.Thirty-eight different outcomes were reported. Repigmentation was the primary outcome in 89% of trials (150 of 169). Forty-nine different tools were used to measure repigmentation. Side-effects and harms were reported in 78% of trials (136 of 174). Maintenance of gained repigmentation was reported in only 11% of trials (20 of 174) and duration of follow-up varied greatly from 1 to 14 months. Cosmetic acceptability of the results and cessation of disease activity were assessed in only 2% of trials (four of 174). Quality of life of patients with vitiligo was assessed in 13% of trials (22 of 174). Finally, only 11 of 112 RCTs (10%) published between 2016 and 2021 reported all three essential core outcome domains (repigmentation, side-effects and maintenance of gained repigmentation) and none of the trials reported both essential and recommended core outcome domains. CONCLUSIONS: Efforts are still needed to close the gap between set recommendations and RCT outcome reporting.

All-Cause and Cause-Specific Mortality Risks among Patients with Hidradenitis Suppurativa: A Korean Nationwide Population-Based Cohort Study.

Although previous studies have reported increased mortality in patients with hidradenitis suppurativa (HS), the cause-specific mortality and the clinical characteristics attributable to greater mortality remain unclear. The aim of this study was to investigate all-cause and cause-specific mortality risks associated with HS. A retrospective population-based cohort study using the data linkage of the Nationwide Health Insurance Service database and the National Death Registry of Korea was conducted. Patients were defined as individuals with ≥3 documented visits with HS from 2003 to 2019. Controls were matched at a 1:10 ratio with age, sex, insurance type, and income level. The study included 26,304 patients with HS and 263,040 controls. Patients with HS showed a higher risk of all-cause mortality (hazard ratio = 1.152, 95% confidence interval = 1.051-1.263) than controls. However, the difference was comparable after further adjustment for body mass index, smoking, drinking, and comorbidity (adjusted hazard ratio = 1.038, 95% confidence interval = 0.946-1.138). For cause-specific mortality, the mortality from suicide/psychiatric disease (adjusted hazard ratio = 1.449, 95% confidence interval = 1.098-2.911) and renal/urogenital disease (adjusted hazard ratio = 1.801, 95% confidence interval = 1.080-3.004) were independently higher among patients with HS even after adjustment for the confounding factors.

Association of All-Cause and Cause-Specific Mortality Risks With Pyoderma Gangrenosum.

Importance: Pyoderma gangrenosum (PG) is a rare neutrophilic dermatosis. Few studies have evaluated the mortality outcomes of patients with PG. Objective: To investigate all-cause and cause-specific mortality in patients with PG. Design, Setting, and Participants: This retrospective population-based cohort study used data from the National Health Insurance Service database of Korea and the National Death Registry of Korea from patients with incident PG (≥3 documented visits with an International Statistical Classification of Diseases and Related Health Problems, Tenth Revision [ICD-10] code of L88) during January 2003 to December 2019. For comparison, a 1:20 cohort of age-, sex-, insurance type-, and income level-matched controls without any documented visit with an ICD-10 code of L88 during the entire observation was included. Exposures: Pyoderma gangrenosum. Main Outcomes and Measures: The participants were observed from the index date to their death, emigration, or the end of the observation period to investigate all-cause and cause-specific mortality during the 17-year study period. Results: In total, 3386 patients with PG (1450 women [42.8%]; mean [SD] age, 57.8 [16.4] years) and 67 720 controls (29 000 women [42.8%]; mean [SD] age, 57.8 [16.3] years) were analyzed. All-cause mortality risk was greater in patients with PG than in controls (adjusted hazard ratio [aHR], 2.122; 95% CI, 1.971-2.285) after adjustment for smoking, drinking, body mass index, and comorbidities. Patients experienced greater mortality of infectious disease (aHR, 3.855; 95% CI, 2.640-5.628), neoplasm (aHR, 1.618; 95% CI, 1.363-1.920), hematologic disease (aHR, 12.298; 95% CI, 3.904-38.734), endocrine disease (aHR, 6.322; 95% CI, 5.026-7.953), neurologic disease (aHR, 2.039; 95% CI, 1.337-3.109), cardiovascular disease (aHR, 1.979; 95% CI, 1.645-2.382), respiratory disease (aHR, 1.757; 95% CI, 1.365-2.263), gastrointestinal disease (aHR, 2.278; 95% CI, 1.522-3.408), connective tissue disease (aHR, 8.685; 95% CI, 4.963-15.199), and kidney/urogenital disease (aHR, 3.617; 95% CI, 2.488-5.259) than controls. Compared with idiopathic PG (aHR, 2.062; 95% CI, 1.897-2.241), PG that was associated with solid organ cancer (aHR, 2.313; 95% CI, 1.956-2.737) and hematologic cancer (aHR, 8.330; 95% CI, 5.473-12.679) showed greater mortality, whereas PG that was associated with inflammatory bowel diseases showed a slightly better prognosis (aHR, 1.742; 95% CI, 0.964-3.148). Conclusions and Relevance: The results of this cohort study suggest that patients with PG had a higher all-cause and cause-specific mortality risk than the general population.

Comorbidities in Patients with Vitiligo: A Systematic Review and Meta-Analysis.

Vitiligo has been reported to be associated with a variety of diseases, but it has not been systematically reviewed. Therefore, we aimed to identify prevalent diseases in patients with vitiligo and quantify their associations compared with those in healthy controls. A comprehensive search of MEDLINE and EMBASE from the inception to June 2022 was conducted. Observational studies on prevalent diseases in patients with vitiligo compared with those in healthy controls were included, whereas studies limited to pediatrics or providing only laboratory results were excluded. A total of 78 studies were eligible for analyses. Patients with vitiligo showed higher risks of having comorbid autoimmune and connective tissue diseases, including alopecia areata (OR = 2.63, 95% confidence interval [CI] = 2.50‒2.78), discoid lupus erythematosus (OR = 2.54, 95% CI = 1.74‒3.72), Sjogren's syndrome (OR = 2.50, 95% CI = 1.98‒3.16), myasthenia gravis (OR = 2.30, 95% CI = 1.74‒3.02), systemic lupus erythematosus (OR = 1.96, 95% CI = 1.52‒2.52), and rheumatoid arthritis (OR = 1.82, 95% CI = 1.55‒2.15). Thyroid diseases, diabetes mellitus, metabolic syndrome, sensorineural hypoacusis, and ophthalmic abnormalities were also more prevalent in patients with vitiligo. In conclusion, vitiligo is associated with various systemic diseases. Physicians should evaluate and manage potential comorbid conditions in patients with vitiligo.

Intralesional immunotherapy for non-genital warts: A systematic review and meta-analysis.

Background Intralesional immunotherapy has been reported to be effective for warts and to show good safety profiles, but this has not yet been systematically studied. Aims To determine the efficacy and safety of intralesional immunotherapy for treating non-genital warts. Methods We comprehensively searched the MEDLINE, Embase, Web of Science and Cochrane Library databases from the times of their inception to January 3, 2020. The primary outcome was the rate of complete response of all lesions. The distant complete response rate of warts located in an anatomically different body part and the recurrence rate were also analyzed. Results A total of 54 prospective studies was ultimately included. The immunotherapeutic agents used were Mycobacterium w vaccine, measles, mumps and rubella vaccine, purified protein derivative, Candida antigen, interferon, bacillus Calmette-Guérin vaccine and others. The pooled rate of complete response among all patients with non-genital warts treated using intralesional immunotherapy was 60.6% (95% confidence interval 54.8-66.5%). The pooled recurrence rate was 2.0% (95% confidence interval, 1.1-2.9%). All reported adverse events were mild and transient. Limitations The heterogeneity among studies Conclusion Intralesional immunotherapy is suggested for use in patients with multiple warts, given its promising results, good safety profile and low recurrence rate.

Comparison of Th1 and Th17 Inflammatory Cytokine Profiles Between Chronic Plaque and Acute Guttate Psoriasis.

Background: The phenotypic heterogeneity of psoriasis is suspected to reflect differences in its pathogenesis, but not yet completely elucidated. Studies of the Th1 and Th17 cytokines associated with different phenotypes of psoriasis have yielded inconsistent results. Objective: To investigate the tissue expression levels of Th1 and Th17 cytokines among patients with chronic plaque psoriasis, acute guttate psoriasis, and healthy control. Methods: A total of 20 patients with psoriasis (10 with chronic plaque type and 10 with acute guttate type) and 5 healthy controls were enrolled. The tissue mRNA and protein levels of following cytokines were measured: interleukin (IL)-12, IL-2, interferon (IFN)-γ, IL-23, IL-17A, and IL-22. Results: The tissue mRNA levels of IL-12, IFN-γ, IL-23, IL-17A, IL-22 and the protein levels of IL-12, IL-2, IFN-γ, IL-17A, IL-22 were significantly increased in the psoriasis patients compared with the healthy controls. In comparisons of the subtypes, the tissue mRNA level of IFN-γ was increased in acute guttate psoriasis, whereas the protein levels of IL-12 and IL-17A were significantly increased in chronic plaque psoriasis. The cytokine ratios of IL-17A/IL-2 and IL-22/IL-2 were significantly higher in chronic plaque psoriasis than in acute guttate psoriasis. Conclusion: We confirmed that the tissue levels of Th1 and Th17 cytokines were increased in psoriasis patients compared with healthy controls. The increased IFN-γ mRNA level in acute guttate psoriasis and increased IL-12 and IL-17A protein levels in chronic plaque psoriasis suggest that an imbalance between Th1 and Th17 cytokines may play a role in the phenotypic transition of psoriasis.