Chronic urticaria associated with Blastocystis hominis infection.

Urticaria is a skin rash with several etiologic factors, including infectious agents. Blastocystis hominis is an intestinal protozoan parasite that has been linked to urticaria and skin lesions. The aim of this work was to investigate the association between B. hominis infection and chronic urticaria. In a case-control study, stool samples were obtained from 94 patients with chronic urticaria as case group and 285 healthy individuals as control group. Urticaria activity score 7 (UAS7) was used to score the severity of urticaria, classified as mild, moderate and intense. All stool samples underwent routine stool examinations, as well as polymerase chain reaction (PCR) for the detection of B. hominis. Molecular detection was carried out using the small subunit ribosomal RNA (SSU-rRNA) gene and the parasite subtypes were determined by sequencing. The rate of B. hominis infection was 21.3% (20 out of 94) and 17.2% (49 out of 285) between the case and control groups, respectively (p = 0.463). Three subtypes of B. hominis, including ST-1, ST-2 and ST-3, were detected in the case and control groups (ST-1 = 30% vs. 8.3%, ST-2 = 40% vs. 25% and ST-3 = 30% vs. 66.6% in the case and control group, respectively), which was statistically significant (p = 0.00001). However, no statistical differences were found between the severity of the urticaria and the B. hominis subtypes (p = 0.533). This study revealed a higher prevalence (but not significant) of B. hominis infection among patients with urticaria than healthy individuals. However, the results did not find a significant association between the subtypes of B. hominis and the severity of urticaria.

PD-BAT: A novel approach of pooling basophil donors for expansion of commercial laboratory testing of Chronic Spontaneous Urticaria.

The type II autoimmune subtype of Chronic Spontaneous Urticaria (CSU) is characterized by the presence of IgG autoantibodies targeting IgE or the IgE high-affinity receptor (FcεRI) on mast cells and basophils. In evaluation of CSU patients, indirect basophil activation testing (BAT), has been utilized, involving the mixing of patient serum with heterologous peripheral blood donors, followed by flow cytometric assessment of basophil markers. However, the reliability of the indirect BAT results hinges on the quality of the donor basophils utilized. In this study, we introduce an innovative approach where multiple potential basophil donors undergo rigorous BAT characterization alongside control samples. By selecting and pooling donors with optimal performance, we significantly enhance the inter-assay reproducibility of the indirect BAT test.

Increased Neutrophil-Lymphocyte Ratio and Platelet-Lymphocyte Ratio in Chronic and Severe Urticaria.

Chronic spontaneous urticaria (CSU) is a disturbing skin condition often severely detrimental to quality of life. Haematological markers of inflammation such as neutrophil-to-lymphocyte and platelet-to-lymphocyte may be used in the assessment of inflammatory skin diseases. Their usefulness in urticaria is unknown. Neutrophil- to-lymphocyte, platelet-to-lymphocyte, and total serum IgE were investigated in urticaria patients: acute spontaneous urticaria (ASU) versus CSU, children versus adults with CSU, and patients with mild-to-moderate versus severe CSU. This retrospective cohort study included patients of all ages diagnosed with urticaria between 2005 and 2020 and blood counts within 30 days of diagnosis. Patients with comorbidities influencing blood cells (infection, surgery, malignancy) were excluded. Neutrophil-to-lymphocyte and platelet-to-lymphocyte were evaluated in patients with ASU vs CSU and mild-to-moderate CSU vs severe CSU (defined by the use of systemic medications or hospitalizations). A total of 13,541 urticaria patients were included in the study. CSU patients (n = 5,021) had higher neutrophil-to-lymphocyte and platelet-to-lymphocyte, as well as serum IgE levels compared with ASU patients (n = 8,520). Adults had higher neutrophil-to-lymphocyte and platelet-to-lymphocyte than children. Severely affected patients (n = 53) had higher neutrophil-to-lymphocyte and platelet-to-lymphocyte compared with mild-to-moderately affected patients (n = 4,968). Patients with higher neutrophil-to-lymphocyte and platelet-to-lymphocyte had higher odds of having CSU rather than ASU and severe urticaria rather mild-to-moderate. In conclusion, neutrophil-to-lymphocyte and platelet-to-lymphocyte are simple and available markers that can be used to predict and assess severe and chronic urticaria.

[The disease under chronic urticaria: beyond itching]. / La enfermedad crónica bajo la urticaria: más allá del prurito.

BACKGROUND: Brief erythematous-papular skin rashes suggest the diagnosis of urticaria; However, it may be another type of dermatitis, and complementary examinations must be carried out to establish its diagnosis. CASE REPORT: 53-year-old female patient, diagnosed in 2016 with diffuse large B cell lymphoma, in complete remission. Since 2010, he has had episodes of erythematous-papular lesions lasting 24-36 hours. He received antihistamines, corticosteroids and omalizumab without clinical improvement. The ANA determination was positive (1/320), nuclear mitotic pattern. The skin biopsy was compatible with dermatitis herpetiformis. The study of celiac and locus antibodies showed positivity for HLA-DQ2 and DQ2.5 in heterozygosity. The diagnosis of dermatitis herpetiformis was established. Treatment consisted of a gluten-free diet and prescription of dapsone, with satisfactory results. CONCLUSION: It is important to establish the differential diagnosis of patients with chronic urticaria who do not respond to the reference treatment, in addition to carrying out a thorough clinical examination and physical examination before starting treatment and relying on a multidisciplinary team to establish an accurate diagnosis and treatment. appropriate. Due to the side effects of dapsone, subsequent follow-up of patients is essential.

ANTECEDENTES: Los exantemas cutáneos eritemato-papulares de breve duración sugieren el diagnóstico clínico de urticaria; no obstante, puede tratarse de otro tipo de dermatitis, y para establecer el diagnóstico deben llevarse a cabo exploraciones complementarias. REPORTE DE CASO: Paciente femenina de 53 años, diagnosticada en 2016 con linfoma difuso de células B grandes, en remisión completa. Desde el 2010 manifestó episodios de lesiones eritemato-papulosas, de 24-36 horas de duración. Recibió antihistamínicos, corticoides y omalizumab sin mejoría clínica. La determinación de ANA resultó positiva (1/320), con patrón mitótico nuclear. La biopsia cutánea fue compatible con dermatitis herpetiforme. El estudio de anticuerpos de celiaquía y locus mostró positividad para HLA-DQ2 y DQ2.5 con heterocigosis. Se estableció el diagnosticó de dermatitis herpetiforme. El tratamiento consistió en dieta exenta de gluten y prescripción de dapsona, con resultados satisfactorios. CONCLUSIÓN: Es importante establecer el diagnóstico diferencial de pacientes con urticaria crónica que no responden al tratamiento de referencia, además de efectuar el examen clínico y la exploración física exhaustivos antes de iniciar el protocolo, y apoyarse de un equipo multidisciplinario para establecer el diagnóstico certero y tratamiento adecuado. Debido a los efectos secundarios de la dapsona, es imprescindible el seguimiento posterior de los pacientes.

Impact of Chronic Spontaneous or Inducible Urticaria on Occupational Activity.

The impact of chronic urticaria on work has been scarcely reported, whereas its peak incidence is between the ages of 20 and 40. The aim of this study was to assess the occupational impact of chronic urticaria and its treatment, by combining objective and patient-reported data. A monocentric observational study was performed using questionnaires over a 1-year period from 2021 to 2022 in chronic urticaria patients who were in a period of professional activity and agreed to participate. Of the 88 patients included, 55.7% assessed the occupational impact of their chronic urticaria as significant, and even more severe when chronic urticaria was poorly controlled. Some 86% of patients had symptoms at work, in a third of cases aggravated by work. However, occupational physical factors were not associated with an aggravation of inducible chronic urticaria. A total of 20% reported treatment-related adverse effects affecting their work. Despite low absenteeism, presenteeism and reduced productivity were important (> 20%). Six patients (6.8%) had difficulties keeping their work. For 72.7% of the patients, the occupational physician was not informed. The occupational impact of chronic urticaria should be discussed during consultations, particularly when it is insufficiently controlled. The occupational physician should be informed in order to support patients' professional project.

Intersecting pathways: evaluating inflammatory markers and metabolism in chronic spontaneous urticaria with a multi-marker approach.

BACKGROUND: Chronic spontaneous urticaria (CSU) is an inflammatory skin disease with intricate mechanisms. This study comprehensively assessed markers from diverse metabolic pathways, including novel inflammatory indicators, to evaluate their potential for diagnosing and monitoring CSU. MATERIALS AND METHODS: In the study involving 90 CSU patients and 90 healthy controls, the levels of albumin, high-density lipoprotein (HDL), fibrinogen, uric acid, D-dimer, C-reactive protein (CRP), and white blood cells (WBC) values were analyzed. The D-dimer/albumin ratio (DAR), fibrinogen/albumin ratio (FAR), and uric acid/HDL ratio (UHR), considered novel inflammatory markers, were calculated. The Urticaria Activity Score 7 (UAS7) was also calculated. Pearson chi-squared test, Mann-Whitney U test, Spearman correlation coefficient, and univariate logistic regression analysis were employed for data analysis. RESULTS: In the patient group, significant elevations were observed in DAR, FAR, fibrinogen, CRP, D-dimer, and UHR values. Additionally, albumin, HDL, and uric acid values exhibited significant decreases. HDL and albumin provided the most accurate results in the univariate logistic regression analysis. CRP had less accuracy, FAR exhibited greater accuracy than fibrinogen, and DAR demonstrated higher accuracy than D-dimer. There was no statistically significant correlation between the UAS7 and parameters. The considerable correlation of CRP with other parameters, except D-dimer, was also remarkable. CONCLUSIONS: Indicators from diverse metabolic pathways, including albumin, HDL, uric acid, fibrinogen, D-dimer, and CRP, can be valuable in assessing CSU. In particular, FAR and DAR are emerging as potential markers to consider in the assessment of CSU.

[Recognition and management of relevant comorbidities in chronic spontaneous urticaria]. / Erkennen und Management relevanter Komorbiditäten bei chronischer spontaner Urtikaria.

Various mechanisms contributing to the activity of chronic spontaneous urticaria (CU) have been postulated. Associated comorbidities are increasingly leading to the discovery of further signaling pathways which may support the activity of chronic urticaria or contribute to low-grade systemic inflammation. Moreover psychoimmunological factors may also be involved. The aim of this work is to improve the clinical care of patients with CU by increasing knowledge regarding optional influencing factors due to comorbidities and to possibly influence disease activity. Chronic urticaria due to autoimmune mechanisms may dispose to other autoimmune diseases, especially autoimmune thyroiditis, which can trigger chronic disease. Association of CU with metabolic syndrome has received little attention to date. Obesity may contribute to low-grade systemic inflammation by cytokine-secreting adipose tissue and hence to mediator-release of mast cells. Furthermore, neuroimmunological pathways, especially increased release of substance P, an activating ligand of Mas-related G protein-coupled receptor X2 (MRGPX2) on mast cells, should be addressed when optimizing therapy.

The Alarmin Triad-IL-25, IL-33, and TSLP-Serum Levels and Their Clinical Implications in Chronic Spontaneous Urticaria.

This study delves into the critical role of alarmins in chronic spontaneous urticaria (CSU), focusing on their impact on disease severity and the quality of life (QoL) of patients. We investigated the alterations in alarmin levels in CSU patients and their correlations with the Urticaria Activity Score (UAS7) and the Dermatology Life Quality Index (DLQI). We analyzed serum levels of interleukin-25 (IL-25), interleukin-33 (IL-33), and thymic stromal lymphopoietin (TSLP) in 50 CSU patients, comparing these to 38 healthy controls. The study examined the relationship between alarmin levels and clinical outcomes, including disease severity and QoL. Elevated levels of IL-33 and TSLP in CSU patients (p < 0.0001) highlight their potential role in CSU pathogenesis. Although IL-25 showed higher levels in CSU patients, this did not reach statistical significance (p = 0.0823). Crucially, IL-33's correlation with both UAS7 and DLQI scores underscores its potential as a biomarker for CSU diagnosis and severity assessment. Of the alarmins analyzed, IL-33 emerges as particularly significant for further exploration as a diagnostic and prognostic biomarker in CSU. Its substantial correlation with disease severity and impact on QoL makes it a compelling candidate for future research, potentially serving as a target for therapeutic interventions. Given these findings, IL-33 deserves additional investigation to confirm its role and effectiveness as a biomarker and therapeutic target in CSU.

A Case-Control Study Comparing the General Characteristics of Patients with Symptomatic Dermographism and Chronic Spontaneous Urticaria: Is Atopy a Risk Factor for Symptomatic Dermographism?

INTRODUCTION: Symptomatic dermographism (SDerm) is the most common chronic inducible urticaria (CIndU) subtype. There is still limited information in the literature about clinical features, triggering factors, and accompanying comorbidities of SDerm. The aim of this study was to compare the clinical features and laboratory data of patients with SDerm and chronic spontaneous urticaria (CSU). METHODS: The clinical features and laboratory data of patients with SDerm and CSU were compared retrospectively. The laboratory data and general characteristic features of the patients were obtained from the medical records. RESULTS: The study included a total of 361 patients (CSU: 220, SDerm: 141). The rates of asthma (odds ratio [OR]: 1.79, p = 0.036), allergic rhinitis (OR: 6.03, p < 0.001), and thyroid disease (OR: 1.78, p = 0.039) were higher in patients with SDerm. The disease duration (median 12 months, p < 0.001) and regular antihistamine use (OR: 0.31, p < 0.001) were lower in patients with SDerm. Total IgE level (median: 193, p < 0.001), thyroid antibody positivity (OR: 1.93, p = 0.039), and atopy (OR: 8.81, p < 0.001) were higher in patients with SDerm. Dermatophagoides pteronyssinus (OR: 17.72, p < 0.001), Dermatophagoides farinae (OR: 17.20, p < 0.001), grass pollen (OR: 2.50, p < 0.026), cat epithelium (OR: 3.68, p < 0.023), and cockroach (OR: 4.93, p < 0.009) allergen positivity rates were higher in patients with SDerm. CONCLUSION: Atopic diseases such as asthma and allergic rhinitis and the sensitization rate to aeroallergens seem to be higher in patients with SDerm than in patients with CSU. The results of this study should be supported by multicenter studies of patients from different geographical regions.

[Practical update for the diagnosis and treatment of chronic urticaria]. / Actualización práctica de diagnóstico y tratamiento de la urticaria crónica.

Urticaria is a distinctive pattern of inflammatory response of the skin and/or mucous membranes characterized by the sudden appearance of vanishing wheals, angioedema, or both, associated with pruritus. Acute forms are frequent and limited to outbreaks of less than 6 weeks; while the chronic ones have a prevalence of less than 1%, longer duration and can be spontaneous or inducible. The etiopathogenic mechanisms involved in this disease include autoallergy, autoimmunity, and inflammation with cell activation, mainly of the mast cell, leading to its degranulation with the release of vasoactive mediators. Along its approach, diagnostic confirmation, search for indicators of its etiopathogenesis, detection of cofactors that can modulate its activity, recognition of comorbidities, evaluation of possible biomarkers and the assessment of disease activity, impact and control are essential. The pharmacological management aims to control the symptoms, until the urticaria, which is self-resolving, is gone. This is described in a stepwise fashion with increasing complexity.

La urticaria es un patrón distintivo de respuesta inflamatoria de piel y/o mucosas caracterizada por la aparición súbita de ronchas evanescentes, angioedema o ambos, asociados a prurito. Las formas agudas son frecuentes y se limitan a brotes de menos de 6 semanas; mientras que las crónicas tienen una prevalencia menor al 1%, mayor duración y pueden ser espontáneas o inducibles. Los mecanismos etiopatogénicos involucrados en esta enfermedad incluyen la autoalergia, la autoinmunidad y la inflamación con la activación celular, principalmente del mastocito, lo que lleva a su degranulación con liberación de mediadores vasoactivos. En su abordaje son fundamentales la confirmación diagnóstica; la búsqueda de indicadores de su etiopatogenia; la detección de cofactores que pueden modular su actividad; el reconocimiento de comorbilidades; la evaluación de posibles biomarcadores y, el impacto en la calidad de vida, el registro de la actividad y el control de la enfermedad. El manejo farmacológico tiene por objetivo controlar los síntomas, mientras la urticaria resuelve de forma espontánea. Este se describe de forma escalonada con una complejidad creciente.

Clinical Response to Low-dose Omalizumab Treatment in Chronic Spontaneous Urticaria: A Retrospective Study of 179 Patients.

Omalizumab is effective in chronic spontaneous urticaria unresponsive to antihistamines. Of the licensed dosing schedules, Korean patients prefer a low dose, of 150 mg/month, for financial reasons. However, real-world experiences of low-dose omalizumab consumption have not been reported. The aim of this retrospective study was to assess the treatment outcomes and long-term clinical course of patients with chronic spontaneous urticaria who were treated with low-dose omalizumab. The study included 179 patients aged ≥ 20 years who were treated with omalizumab 150 mg/month for ≥ 12 weeks. Baseline disease activity was mild, moderate, and severe in 54.7%, 35.2%, and 10.1% of patients, respectively. A complete response was observed in 133 patients at 12 weeks, among whom 88 patients showed early responses within 4 weeks. Overall, 158 patients finally achieved a complete response. Multivariate analyses revealed that baseline disease activity is more likely to be mild in patients who experience early and final complete responses. The absence of atopic comorbidities correlated with an early response. Smoking was associated with a final complete response. This study shows that low-dose omalizumab provides favourable treatment outcomes in antihistamine-refractory chronic spontaneous urticaria. Disease severity, atopic comorbidity, and smoking may be predictive factors for studying the response to omalizumab.

Anti-TPO IgG/Total IgE Ratio: Biomarker for Omalizumab Response Prediction in Chronic Spontaneous Urticaria.

BACKGROUND: According to recently published data, low total IgE, elevated IgG-anti-TPO, and a high IgG-anti-TPO/total IgE ratio are good biomarkers for subtype IIb autoimmune chronic spontaneous urticaria (CSU), which is frequently refractory to antihistamines and omalizumab. OBJECTIVES: The aim of the study was to evaluate IgG-anti-TPO/total IgE ratio's utility in omalizumab response prediction. METHODS: Retrospective study of CSU patients treated with omalizumab at a UCARE between January 2009 and February 2022. Patients were grouped according to response in the first 16 weeks of treatment: responders UAS7 < 7 versus partial/non-responders UAS7≥7. Total IgE, IgG-anti-TPO, and IgG-anti-TPO/total IgE ratio were compared. Other inflammatory biomarkers - eosinophils, basophils, C-reactive protein, erythrocyte sedimentation rate, and d-dimer - were analyzed. STATISTICAL ANALYSIS: SPSS® (v25.0), p < 0.05 statistically significant. RESULTS: Total of 175 patients, 140 (80%) women, median age 49 [9-88] years, mean CSU duration pre-omalizumab 5.6 ± 8.2 [0-54] years, omalizumab duration 3.2 ± 2.5 [0-12] years. 116 (66%) had angioedema, 77 (44%) inducible chronic urticaria, 60 (34%) atopy, 24 (14%) autoimmune disease. With omalizumab 300 mg q4 weeks, 69% were responders and 31% partial/non-responders. Although not reaching significant differences, mean total IgE values were lower and mean IgG-anti-TPO values were higher in partial/non-responders versus responders (152 vs. 242 kU/L, p = 0.207, and 38.3 vs. 25.7 U/mL, p = 0.408, respectively). A higher IgG-anti-TPO/total IgE ratio was significantly associated with poorer response to omalizumab (p = 0.040). A cut-off >0.154 increased 10 times the odd of poorer response [95% CI 4.62-22], AUC 0.872, p < 0.001, with 87.7% sensitivity, although the low specificity (22.4%) does not allow the assumption of response with values <0.154. Other laboratory biomarkers did not show significant differences between partial/non-responders versus responders. CONCLUSIONS: A high IgG-anti-TPO/total IgE ratio was a good biomarker of poor response to omalizumab in our CSU cohort, with a cut-off >0.154 increasing 10 times the odd of poorer response.

Positive Basophil Tests Are Linked to High Disease Activity and Other Features of Autoimmune Chronic Spontaneous Urticaria: A Systematic Review.

BACKGROUND: Chronic spontaneous urticaria (CSU) is believed to be Autoimmune (aiCSU) (type IIb CSU) in at least 8% of patients, associated with mast cell-activating IgG autoantibodies. Basophil tests such as the basophil activation test (BAT) and basophil histamine release assay (BHRA) are considered the best single tests for an aiCSU diagnosis. To date, the strength of associations among a positive BAT and/or BHRA (BAT/BHRA+) and CSU features, patient demographics, and response to treatment remains poorly characterized. OBJECTIVE: To evaluate the strength of current evidence on basophil tests as parameters for CSU characteristics. METHODS: We performed a systematic literature search and review to assess the relationship between BAT/BHRA+ and clinical and laboratory parameters of CSU. Of 1,058 records found in the search, 94 studies were reviewed by experts in urticaria and 42 were included in the analysis. RESULTS: In CSU patients, BAT/BHRA+ showed a strong level of evidence for an association with high disease activity and low levels of total IgE. A weak level of evidence was shown for the association of BAT/BHRA+ and the presence of angioedema, and basopenia. CONCLUSIONS: Our results suggest that aiCSU defined by BAT/BHRA+ is more active or severe and is linked to other aiCSU markers such as low total IgE/basopenia. Basophil tests should be standardized and implemented in routine clinical care to improve the diagnosis and treatment of patients with aiCSU.

The 7-day recall period version of the Urticaria Control Test-UCT7.

BACKGROUND: The Urticaria Control Test (UCT) is a well-established, very easy to use and calculate 4-item patient-reported outcome measure to assess chronic urticaria disease control during the previous 4 weeks. Clinical trials and practice may benefit from the use of a UCT version with a shorter recall period, but this does not exist. OBJECTIVES: We sought to develop and validate a UCT version with a 7-day recall period, the UCT7. METHODS: The UCT7 was developed, based on the UCT, and tested, in 152 patients with chronic urticaria (spontaneous: n = 101, inducible: n = 51) for its reliability, validity and screening accuracy, and clinimetric properties, in other words, the cutoff for well-controlled disease and the minimal clinically important difference. RESULTS: The UCT7 showed excellent internal consistency reliability with a Cronbach αvalue of 0.91 and test-retest reliability with an intraclass correlation coefficient of 0.83. Convergent validity was high and strongly correlated with anchors of disease control, wheal and angioedema frequency, and urticaria-related quality of life impairment. The UCT7 showed excellent sensitivity to change; however, changes in angioedema activity and impact did not correlate well with changes in UCT7. Based on receiver-operating characteristic curve analysis, the proportion of correctly classified patients, and patients' assessment of treatment efficacy, we recommend a cutoff value of 12 points for identifying patients with well-controlled disease. The UCT7 minimal clinically important difference for improvement was estimated to be 2 points. CONCLUSIONS: The UCT7 is a validated 7-day recall period version of the UCT. It is ideal for the assessment of disease control at short intervals in patients with chronic urticaria in clinical studies and practice.

Drugs in Development for Chronic Spontaneous Urticaria.

BACKGROUND: Chronic spontaneous urticaria (CSU) is a debilitating disease for which many patients are inadequately treated. However, recent advancements in our understanding of the disease pathophysiology allow us to develop therapies that are more effective for CSU. It may be possible in the future to select personalized treatments based on a patient’s autoimmune endotype. This paper reviews current knowledge on CSU pathogenesis and treatment. It also reviews data for drugs being developed for the treatment of CSU, as listed on ClinicalTrials.gov. J Drugs Dermatol. 2023;22(4): doi:10.36849/JDD.7113 Citation: Nguyen W, Liu W, Paul S. Yamauchi PS. Drugs in development for chronic spontaneous urticaria. J Drugs Dermatol. 2023;22(4):393-397. doi:10.36849/JDD.7113.

S3 Guideline Urticaria. Part 2: Treatment of urticaria - German-language adaptation of the international S3 guideline.

This publication is the second part of the German-language S3 guideline on urticaria. It covers the management of urticaria and should be used together with Part 1 of the guideline on classification and diagnosis. This publication was prepared according to the criteria of the AWMF on the basis of the international English-language S3 guideline with special consideration of health system conditions in German-speaking countries. Chronic urticaria has a high impact on the quality of life and daily activities of patients. Therefore, if causal factors cannot be eliminated, effective symptomatic treatment is necessary. The recommended first-line treatment is to administer new generation, non-sedating H1 antihistamines. If the standard dose is not sufficiently effective, the dose should be increased up to fourfold. For patients who do not respond to this treatment, the second-line treatment in addition to antihistamines in the treatment algorithm is omalizumab and, if this treatment fails, ciclosporin. Other low-evidence therapeutic agents should only be used if all treatments in the treatment algorithm agreed upon by the guideline group fail. Both the benefit-risk profile and cost should be considered. Corticosteroids are not recommended for long-term treatment due to their inevitable severe side effects.