Transcriptional licensing is required for Pyrin inflammasome activation in human macrophages and bypassed by mutations causing familial Mediterranean fever.

Pyrin is a cytosolic immune sensor that nucleates an inflammasome in response to inhibition of RhoA by bacterial virulence factors, triggering the release of inflammatory cytokines, including IL-1ß. Gain-of-function mutations in the MEFV gene encoding Pyrin cause autoinflammatory disorders, such as familial Mediterranean fever (FMF) and Pyrin-associated autoinflammation with neutrophilic dermatosis (PAAND). To precisely define the role of Pyrin in pathogen detection in human immune cells, we compared initiation and regulation of the Pyrin inflammasome response in monocyte-derived macrophages (hMDM). Unlike human monocytes and murine macrophages, we determined that hMDM failed to activate Pyrin in response to known Pyrin activators Clostridioides difficile (C. difficile) toxins A or B (TcdA or TcdB), as well as the bile acid analogue BAA-473. The Pyrin inflammasome response was enabled in hMDM by prolonged priming with either LPS or type I or II interferons and required an increase in Pyrin expression. Notably, FMF mutations lifted the requirement for prolonged priming for Pyrin activation in hMDM, enabling Pyrin activation in the absence of additional inflammatory signals. Unexpectedly, in the absence of a Pyrin response, we found that TcdB activated the NLRP3 inflammasome in hMDM. These data demonstrate that regulation of Pyrin activation in hMDM diverges from monocytes and highlights its dysregulation in FMF.

Monitoring of Adverse Events and Safety in Autoinflammatory Diseases: Real-Life Data from the Eurofever Registry.

OBJECTIVES: The study is aimed to evaluate the impact of safety events in the Eurofever registry for Autoinflammatory diseases. METHODS: This was a retrospective and longitudinal observational multicentre study. Data were retrieved from the international registry Eurofever, starting patients' enrolment since 2009. All moderate, severe, or very severe AEs reported by treating physician in Eurofever were analyzed regardless of a possible suspected causal relationship to any therapies and according to the latest release of the Medical Dictionary for Regulatory Activities. RESULTS: Complete information on safety were available in 2464 patients enrolled in the registry. In 1499 of them retrospective data encompassing the period from disease onset to enrolment were available, whereas 965 consecutive patients entered in the longitudinal part of the study. A total of 479 AEs have been reported in 275 patients. Eighty-two AEs were reported as serious and 99 were drug-related according to the physicians. Infections or infestations (94; 19.6%), gastrointestinal disorders (66; 13.8%), nervous system disorders (41; 8.6%) and systemic disorders or administration site reactions (35; 7.3%) were the most frequent reported events. The highest absolute number of drug-related AEs were related to biologic DMARDs (40/99 reports, 40,4%) and colchicine (31/99 reports, 31.3%). CONCLUSIONS: Present study shows the importance of a longitudinal and homogeneous registration of the AEs in rare conditions, with a particular focus on the safety profile of the treatments used in these conditions.

Translation of cytoplasmic UBA1 contributes to VEXAS syndrome pathogenesis.

Somatic mutations in UBA1 cause vacuoles, E1 ubiquitin-activating enzyme, X-linked, autoinflammatory somatic (VEXAS) syndrome, an adult-onset inflammatory disease with an overlap of hematologic manifestations. VEXAS syndrome is characterized by a high mortality rate and significant clinical heterogeneity. We sought to determine independent predictors of survival in VEXAS and to understand the mechanistic basis for these factors. We analyzed 83 patients with somatic pathogenic variants in UBA1 at p.Met41 (p.Met41Leu/Thr/Val), the start codon for translation of the cytoplasmic isoform of UBA1 (UBA1b). Patients with the p.Met41Val genotype were most likely to have an undifferentiated inflammatory syndrome. Multivariate analysis showed ear chondritis was associated with increased survival, whereas transfusion dependence and the p.Met41Val variant were independently associated with decreased survival. Using in vitro models and patient-derived cells, we demonstrate that p.Met41Val variant supports less UBA1b translation than either p.Met41Leu or p.Met41Thr, providing a molecular rationale for decreased survival. In addition, we show that these 3 canonical VEXAS variants produce more UBA1b than any of the 6 other possible single-nucleotide variants within this codon. Finally, we report a patient, clinically diagnosed with VEXAS syndrome, with 2 novel mutations in UBA1 occurring in cis on the same allele. One mutation (c.121 A>T; p.Met41Leu) caused severely reduced translation of UBA1b in a reporter assay, but coexpression with the second mutation (c.119 G>C; p.Gly40Ala) rescued UBA1b levels to those of canonical mutations. We conclude that regulation of residual UBA1b translation is fundamental to the pathogenesis of VEXAS syndrome and contributes to disease prognosis.

Clinical presentation and genetic variants in patients with autoinflammatory diseases: results from the German GARROD registry.

To investigate clinical symptoms and genetic variants in patients from the German anti-IL-1 registry for autoinflammatory orphan diseases (GARROD) between 2013 and 2022. Multicentre, retrospective analysis of demographic, clinical and genetic data of patients with autoinflammatory diseases (AID) who received anti-IL-1 targeted therapy. The cohort comprised 152 patients with familial Mediterranean fever (FMF; n = 71), cryopyrin-associated periodic syndromes (CAPS; n = 43), TNF-receptor associated periodic syndrome (TRAPS; n = 19), mevalonate kinase deficiency (MKD; n = 3) and unclassified AID (uAID; n = 16). Inflammatory attacks started in 61.2% of the patients before the age of 18 years. The delay between the first AID attack and anti-IL-1 therapy was 17.8 years. Monogenetic AIDs were diagnosed by clinical symptoms. Genetic analyses confirmed the diagnosis in 87.3% of patients with FMF, 65.2% with CAPS and 94.8% with TRAPS. Among this group, heterozygous MEFV variants and variants of unknown significance (VUS) were detected in 22.5% of patients with FMF, 51.2% with CAPS and 47.4% with TRAPS. Patients with VUS were older at disease onset which is consistent with a milder phenotype. Twenty-four patients had secondary AA amyloidosis (AA) at initiation of anti-IL-1 therapy. The mean age of these patients was 16.4 years at their first attack and 44.9 years at the time of AA diagnosis. Turkish-Armenian ancestry correlated with MEFV variants and higher FMF disease activity compared to German ancestry. Molecular genetic analyses should substantiate the clinical diagnosis of a monogenetic AID. Our data support the concept of variable penetrance of VUS which can be associated with late-onset AID.

Treatment patterns and outcomes in patients with chronic urticaria during pregnancy: Results of PREG-CU, a UCARE study.

BACKGROUND: Although chronic urticaria (CU) is a common and primarily affects females, there is little data on how pregnancy interacts with the disease. OBJECTIVE: To analyse the treatment use by CU patients before, during and after pregnancy as well as outcomes of pregnancy. METHODS: PREG-CU is an international, multicentre study of the Urticaria Centers of Reference and Excellence network. Data were collected via a 47-item-questionnaire completed by CU patients who became pregnant during their disease course. RESULTS: Questionnaires from 288 CU patients from 13 countries were analysed. During pregnancy, most patients (60%) used urticaria medication including standard-dose second generation H1-antihistamines (35.1%), first generation H1-antihistamines (7.6%), high-dose second-generation H1-antihistamines (5.6%) and omalizumab (5.6%). The preterm birth rate was 10.2%; rates were similar between patients who did and did not receive treatment during pregnancy (11.6% vs. 8.7%, respectively). Emergency referrals for CU and twin birth were risk factors for preterm birth. The caesarean delivery rate was 51.3%. More than 90% of new-borns were healthy at birth. There was no link between any patient or disease characteristics or treatments and medical problems at birth. CONCLUSION: Most CU patients used treatment during pregnancy especially second-generation antihistamines which seem to be safe during pregnancy regardless of the trimester. The rates of preterm births and medical problems of new-borns in CU patients were similar to population norms and not linked to treatment used during pregnancy. Emergency referrals for CU increased the risk of preterm birth and emphasize the importance of sufficient treatment to keep urticaria under control during pregnancy.

The role of mast cells in autoinflammation.

The concept of autoinflammation was proposed to define a new class of immune disorders categorized by self-directed inflammation that is driven via activation of innate immune pathways. Within innate immunity, inflammasomes serve as intracellular signaling platforms to endogenous danger molecules and pathogens. Their key function is the cleavage of pro-interleukin-1ß (pro-IL-1ß) into its active form to promote inflammation and programmed cell death. A growing number of inflammasome sensors were described, among which NLR family pyrin domain containing 3 (NLRP3) is the best-studied sensor. Besides macrophages, monocytes, and other innate immune cells, mast cells (MCs) were shown to express functional inflammasomes too. Also, MCs are both, a source and target of IL-1ß. Here we review the functional relevance and role of MC inflammasomes and MC-derived IL-1ß in contributing to the inflammation at the skin, joints, and central nervous system in rare monogenic autoinflammatory conditions and also common inflammatory and degenerative diseases.

A mutation in the kringle domain of human factor XII that causes autoinflammation, disturbs zymogen quiescence, and accelerates activation.

Coagulation factor XII (FXII) drives production of the inflammatory peptide bradykinin. Pathological mutations in the F12 gene, which encodes FXII, provoke acute tissue swelling in hereditary angioedema (HAE). Interestingly, a recently identified F12 mutation, causing a W268R substitution, is not associated with HAE. Instead, FXII-W268R carriers experience cold-inducible urticarial rash, arthralgia, fever, and fatigue. Here, we aimed to investigate the molecular characteristics of the FXII-W268R variant. We expressed wild type FXII (FXII-WT), FXII-W268R, and FXII-T309R (which causes HAE), as well as other FXII variants in HEK293 freestyle cells. Using chromogenic substrate assays, immunoblotting, and ELISA, we analyzed expression media, cell lysates, and purified proteins for FXII activation. Recombinant FXII-W268R forms increased amounts of intracellular cleavage products that are also present in expression medium and display enzymatic activity. The active site-incapacitated variant FXII-W268R/S544A reveals that intracellular fragmentation is largely dependent on autoactivation. Purified FXII-W268R is highly sensitive to activation by plasma kallikrein and plasmin, compared with FXII-WT or FXII-T309R. Furthermore, binding studies indicated that the FXII-W268R variant leads to the exposure of a plasminogen-binding site that is cryptic in FXII-WT. In plasma, recombinant FXII-W268R spontaneously triggers high-molecular-weight kininogen cleavage. Our findings suggest that the W268R substitution influences FXII protein conformation and exposure of the activation loop, which is concealed in FXII-WT. This results in intracellular autoactivation and constitutive low-grade secretion of activated FXII. These findings help to explain the chronically increased contact activation in carriers of the FXII-W268R variant.

Effects of pregnancy on chronic urticaria: Results of the PREG-CU UCARE study.

BACKGROUND: Chronic urticaria (CU) predominantly affects women, and sex hormones can modulate disease activity in female CU patients. As of now, the impact of pregnancy on CU is largely unknown. AIM: To analyze the course and features of CU during and after pregnancy. PATIENTS AND METHODS: PREG-CU is an international, multicenter study of the Urticaria Centers of Reference and Excellence (UCARE) network. Data were collected via a 47-item questionnaire completed by CU patients, who became pregnant within the last 3 years. RESULTS: A total of 288 pregnancies of 288 CU patients from 13 countries were analyzed (mean age at pregnancy: 32.1 ± 6.1 years, duration of CU: 84.9 ± 74.5 months; CSU 66.9%, CSU + CIndU 20.3%, CIndU 12.8%).During pregnancy, 51.1% of patients rated their CU as improved, 28.9% as worse, and 20.0% as unchanged.CU exacerbations most commonly occurred exclusively during the third trimester (in 34 of 124 patients; 27.6%) or the first (28 of 124; 22.8%). The risk factors for worsening of CU during pregnancy were having mild disease and no angioedema before pregnancy, not taking treatment before pregnancy, CIndU, CU worsening during a previous pregnancy, treatment during pregnancy, and stress as a driver of exacerbations. After giving birth, urticaria disease activity remained unchanged in 43.8% of CU patients, whereas 37.4% and 18.1% experienced worsening and improvement, respectively. CONCLUSIONS: These results demonstrate the complex impact of pregnancy on the course of CU and help to better counsel patients who want to become pregnant and to manage CU during pregnancy.

Development of the Angioedema Control Test-A patient-reported outcome measure that assesses disease control in patients with recurrent angioedema.

BACKGROUND: Recurrent angioedema (AE) is an important clinical problem in the context of chronic urticaria (mast cell mediator-induced), ACE-inhibitor intake and hereditary angioedema (both bradykinin-mediated). To help patients obtain control of their recurrent AE is a major treatment goal. However, a tool to assess control of recurrent AE is not yet available. This prompted us to develop such a tool, the Angioedema Control Test (AECT). METHODS: After a conceptional framework was developed for the AECT, a list of potential AECT items was generated by a combined approach of patient interviews, literature review and expert input. Subsequent item reduction was based on impact analysis, inter-item correlation, additional predefined criteria for item performance, and a review of the item selection process for content validity. Finally, an instruction section was generated, and an US-American-English version was developed by a structured translation process. RESULTS: A 4-item AECT with recall periods of 4 weeks and 3 months was developed based on 106 potential items tested in 97 patients with mast cell mediator-induced (n = 49) or bradykinin-mediated recurrent AE (n = 48). Eighty-four items were excluded based on impact analysis. The remaining 22 items could be further reduced by a method-mix of inter-item correlation, additional predefined criteria for item performance and review for content validity. CONCLUSIONS: The AECT is the first tool to assess disease control in recurrent AE patients. Its retrospective approach, its brevity and its simple scoring make the AECT ideally suited for clinical practice and trials. Its validity and reliability need to be determined in future independent studies.

Spectrum of Genetic Autoinflammatory Diseases Presenting with Cutaneous Symptoms.

Autoinflammatory diseases comprise a group of chronic disabling entities characterized by inflammation without the presence of infectious agents, auto-antibodies or antigen-specific T-cells. Many autoinflammatory diseases are caused by monogenic defects, which lead to disturbed immune signalling with release of proinflammatory mediators. In addition to interleukin-1ß and interleukin-18, interferons play a key role in the pathophysiology of these disorders. Patients with autoinflammatory diseases show a broad variety of clinical symptoms, including skin involvement. Wheals, pustules and ulcerative lesions are the most common cutaneous findings observed. Knowledge of the clinical presentation of autoinflammatory diseases is crucial for establishing the diagnosis and guiding appropriate treatment. This review focuses on the dermatological findings in selected autoinflammatory disorders based on their distinct pathomechanisms.

Treatment of urticarial vasculitis: A systematic review.

Urticarial vasculitis (UV) is a difficult-to-treat condition characterized by long-lasting urticarial rashes and histopathologic findings of leukocytoclastic vasculitis. Treatment is dictated by the severity of skin and systemic involvement and the underlying systemic disease. This is a comprehensive systematic review of the efficacy of current UV treatment options. We searched for relevant studies in 7 databases, including MEDLINE, Scopus, and Web of Science. In total, 261 eligible studies and 789 unique patients with UV were included in the systematic review. Most patients with UV are adult women with chronic (≥6 weeks) and systemic disease. UV is mostly idiopathic but can be associated with drugs, malignancy, autoimmunity, and infections. It usually resolves with their withdrawal or cure. Corticosteroids are effective for the treatment of skin symptoms in more than 80% of patients with UV. However, their long-term administration can lead to potentially serious adverse effects. The addition of immunomodulatory or immunosuppressive agents often allows corticosteroid tapering and improves the efficacy of therapy. Biologicals, including omalizumab, as well as corticosteroids, cyclophosphamide, dapsone, mycophenolate mofetil, plasmapheresis, colchicine, hydroxychloroquine, intravenous immunoglobulin, nonsteroidal anti-inflammatory drugs, and cyclosporine, can be effective for both skin and systemic symptoms in patients with UV. H1-antihistamines, montelukast, danazol, H2-antihistamines, pentoxifylline, doxepin, and tranexamic acid are not effective in most patients with UV. As of yet, no drugs have been approved for UV, and management recommendations are based mostly on case reports and retrospective studies. Prospective studies investigating the effects of treatment on the signs and symptoms of UV are needed.

Ultraviolet radiation and skin mast cells: Effects, mechanisms and relevance for skin diseases.

Mast cells (MCs) are well known as versatile effector cells in allergic reactions and several other immune responses. Skin MCs and cutaneous MC responses are subject to the effects of environmental factors including ultraviolet radiation (UVR). Numerous studies have assessed the effects of UVR on MCs, in vitro and in vivo. Interestingly, UVR seems to have variable effects on non-activated and activated mast cells. In general, UV therapy is beneficial in the treatment of urticaria and mastocytosis, but the effects are variable depending on treatment regimen and type of UVR. Here, we review and summarise key reports from the older and current literature on the crosstalk of UVR and skin MCs. Specifically, we present the literature and discuss published reports on the effects of UVR on skin MCs in rodents and humans. In addition, we review the role of MCs in UVR-driven skin diseases and the influence of UV light on MC-mediated skin diseases. This summary of our current understanding of the interplay of skin MCs and UVR may help to improve the management of patients with urticaria and other MC disorders, to identify current gaps of knowledge, and to guide further research.

Efficacy and safety of canakinumab in Schnitzler syndrome: A multicenter randomized placebo-controlled study.

BACKGROUND: Schnitzler syndrome is an adult-onset autoinflammatory disease characterized by urticarial exanthema and monoclonal gammopathy accompanied by systemic symptoms such as fever, bone, and muscle pain. Up to now, approved treatment options are not available. OBJECTIVE: We assessed effects of the anti-IL-1ß mAb canakinumab on the clinical signs and symptoms of Schnitzler syndrome. METHODS: In this phase II, randomized placebo-controlled multicenter study, 20 patients with active disease enrolled in 4 German study centers. Patients were randomly assigned to receive single subcutaneous canakinumab 150 mg or placebo injections for 7 days, followed by a 16-week open-label phase with canakinumab injections on confirmed relapse of symptoms. The primary end point was the proportion of patients with complete clinical response evaluated by physician global assessment at day 7. Key secondary end points included changes in patient-reported disease activity (Schnitzler activity score), inflammation markers (C-reactive protein and serum amyloid A), and quality-of-life assessments (Dermatology Life Quality Index and 36-item short form health survey). RESULTS: The proportion of patients with complete clinical response at day 7 was significantly higher (P = .001) in the canakinumab-treated group (n = 5 of 7) than in the placebo group (n = 0 of 13). Levels of inflammation markers C-reactive protein and serum amyloid A and quality-of-life scores were significantly reduced in canakinumab-treated but not in placebo-treated individuals. Positive effects continued up to 16 weeks. Adverse events were manageable and included respiratory tract infections, gastrointestinal symptoms, and hypertension. CONCLUSIONS: In this first placebo-controlled study, canakinumab was effective in patients with Schnitzler syndrome, and thus canakinumab may be further evaluated as a therapeutic option for this rare disease.

Chronic urticaria - What does the new guideline tell us?

Patients with chronic urticaria experience significant impairment, and require an effective treatment. Such treatment is preceded by a thorough diagnostic workup and measurement of disease activity, disease burden and disease control using well--established tools. Treatment is subsequently adjusted according to patient needs and therapeutic response, based on the tenet "as much as necessary, as little as possible" (in that order). Once disease control has been achieved, it is recommended that intermittent attempts at medication withdrawal be made in order to identify spontaneous disease remission. Chronic urticaria should be treated until spontaneous remission occurs.

Real-life effectiveness of canakinumab in cryopyrin-associated periodic syndrome.

OBJECTIVE: Cryopyrin-associated periodic syndrome (CAPS) is a heterogeneous group of diseases characterized by excessive IL-1ß release resulting in severe systemic and organ inflammation. Canakinumab targets IL-1ß and is approved at standard dose for children and adults with all CAPS phenotypes. Limited data are available for the real-life effectiveness of canakinumab in patients living with CAPS. Therefore the aim of the study was to evaluate the real-life dosing and effectiveness of canakinumab in CAPS. METHODS: A multi-centre study of consecutive children and adults with CAPS treated with canakinumab was performed. Demographics, CAPS phenotype and disease activity, inflammatory markers and canakinumab treatment strategy were recorded. Treatment response was assessed using CAPS disease activity scores, CRP and/or serum amyloid A levels. Comparisons between age groups, CAPS phenotypes and centres were conducted. RESULTS: A total of 68 CAPS patients at nine centres were included. All CAPS phenotypes were represented. Thirty-seven (54%) patients were females, the median age was 25 years and 27 (40%) were children, and the median follow-up was 28 months. Overall, complete response (CR) was seen in 72% of CAPS patients, significantly less often in severe (14%) than in mild CAPS phenotypes (79%). Only 53% attained CR on standard dose canakinumab. Dose increase was more commonly required in children (56%) than in adults (22%). Centres with a treat-to-target approach had significantly higher CR rates (94 vs 50%). CONCLUSION: Real-life effectiveness of canakinumab in CAPS was significantly lower than in controlled trials. Treat-to-target strategies may improve the outcome of children and adults living with CAPS.

Rupatadine 20 mg and 40 mg are Effective in Reducing the Symptoms of Chronic Cold Urticaria.

Chronic cold urticaria (ColdU) is a rare disease characterized by mast cell-mediated wheals and angioedema following cold exposure. Second-generation H1-antihistamines, such as rupatadine, are the recommended first-line therapy. As of yet, the effects of rupatadine up-dosing on development of ColdU symptom have only been partially characterized. Two-centre, randomized, double-blind, 3-way crossover, placebo-controlled study in patients with a confirmed ColdU was designed to assess the effects of up-dosing of rupatadine. A total of 23 patients were randomized to receive placebo, rupatadine 20 mg/day, and rupatadine 40 mg/day for 1 week. The primary outcome was change in critical temperature thresholds and critical stimulation time thresholds after treatment. Secondary endpoints included assessment of safety and tolerability of rupatadine. Both 20 and 40 mg rupatadine were highly effective in reducing critical temperature thresholds (p < 0.001) and critical stimulation time thresholds (p < 0.001). In conclusion, rupatadine 20 and 40 mg significantly reduced the development of chronic cold urticaria symptom without an increase in adverse effects.

Development and validation of the Urticaria Control Test: a patient-reported outcome instrument for assessing urticaria control.

BACKGROUND: Chronic urticaria is a frequent and debilitating skin disease. Its symptoms commonly fluctuate considerably from day to day. As of yet, the only reliable tool to assess disease activity is the Urticaria Activity Score, which prospectively documents the signs and symptoms of urticaria for several days. OBJECTIVE: We sought to develop and validate a novel patient-reported outcome instrument to retrospectively assess urticaria control, the Urticaria Control Test (UCT). METHODS: Potential UCT items were developed by using established methods (literature research and expert and patient involvement). Subsequently, item reduction was performed by using a combined approach, applying impact and regression analysis. The resulting UCT instrument was then tested for its validity, reliability, and screening accuracy. RESULTS: A 4-item UCT with a recall period of 4 weeks was developed based on 25 potential UCT items tested in 508 patients with chronic urticaria. A subsequent validation study with the 4-item UCT in 120 patients with chronic urticaria demonstrated that this new tool exhibits good convergent and known-groups validity, as well as excellent test-retest reliability. In addition, the screening accuracy to identify patients with urticaria with insufficiently controlled disease was found to be high. CONCLUSIONS: The UCT is the first valid and reliable tool to assess disease control in patients with chronic urticaria (spontaneous and inducible). Its retrospective approach and simple scoring system make it an ideal instrument for the management of patients with chronic urticaria in clinical practice.

Development and Validation of a Patient-Reported Outcome Measure to Assess Disease Control in Chronic Prurigo.

Importance: Chronic prurigo (CPG), including prurigo nodularis, is a difficult disease to treat and considerably affects patients' quality of life. Helping patients obtain control of CPG is a major treatment goal. Objective: To develop and validate the Prurigo Control Test (PCT), a tool for assessing disease control in CPG, and to identify a cutoff value for controlled disease to aid treatment decisions. Design, Setting, and Participants: This qualitative study followed the current recommendations for patient-reported outcome measure development in the generation and validation of the PCT. The final PCT was obtained after item generation, followed by reduction and selection, and was then tested for internal consistency and test-retest reliability, convergent validity, known-group validity, screening accuracy, and banding. The item-generation phase resulted in an unselected list of 69 potential PCT items. Impact analysis, interitem correlation, and review for content (face) validity resulted in final set of 5 PCT items. The validation study was performed among patients across 2 expert centers in Germany. Data were analyzed from February 2017 to November 2019. Main Outcomes and Measures: A 5-item PCT with a recall period of 2 weeks was developed. A cutoff value of 10 points or higher was determined as suitable for identifying patients with well-controlled vs poorly controlled CPG. Results: Of the 95 patients included in the validation study, the median (range) age was 63 (19-87) years, 50 patients (53%) were women, and the median (range) disease duration was 72 (9-774) months. The validation study yielded good internal consistency reliability (Cronbach α, 0.86) and a high degree of convergent validity. The PCT demonstrated good known-group validity and could discriminate between patients who differed in prurigo control. Test-retest reliability was high, and the intraclass correlation coefficient was 0.94, indicating excellent reproducibility. Conclusions and Relevance: This qualitative study showed that the PCT is able to assess disease control in patients with CPG. Its retrospective approach, brevity, and simple scoring likely make the PCT suitable for clinical practice and trials.