Other

• Elvebakk, Trude; Døllner, Henrik; Partty, Anna et al. (2025). INnovative Steroid Treatment to reduce Asthma development in children after first-time Rhinovirus-induced wheezing (INSTAR): protocol for a randomised placebo-controlled trial. (external link)

Academic article

• Sørensen, Karen Galta; Øymar, Knut Asbjørn Alexander; Dalen, Ingvild et al. (2025). Bronchial hyper-reactivity in young adults after hospitalisation for bronchiolitis in infancy. (external link)
• Øymar, Maren Våland; Selvakumar, Joel Pradeepkumar; Dalen, Ingvild et al. (2025). Regional Differences and Time Trends in the Treatment of Infants Hospitalised With Bronchiolitis in Norway. (external link)
• Vaula, Sofie Helen; Øymar, Knut Asbjørn Alexander; Hovland, Vegard et al. (2024). Trakeobronkomalasi hos barn. (external link)
• Bårdsen, Tonje; Satrell, Emma; Røksund, Ola Drange et al. (2024). Lung function outcomes in adults born extremely preterm across three decades of advancing perinatal medicine. (external link)
• Huncikova, Zuzana; Vatne, Anlaug; Stensvold, Hans Jørgen et al. (2023). Late-onset sepsis in very preterm infants in Norway in 2009-2018: A population-based study. (external link)
• Huncikova, Zuzana; Stensvold, Hans Jørgen; Øymar, Knut Asbjørn Alexander et al. (2023). Variation in antibiotic consumption in very preterm infants-a 10 year population-based study. (external link)
• Sørensen, Karen Galta; Øymar, Knut Asbjørn Alexander; Dalen, Ingvild et al. (2023). Blood eosinophils during bronchiolitis: Associations with atopy, asthma and lung function in young adults. (external link)
• Sørensen, Karen Galta; Øymar, Knut Asbjørn Alexander; Jonsson, Grete et al. (2023). Are BMI and adipokines associated with asthma, atopy and lung function in young adults previously hospitalized for bronchiolitis?. (external link)
• Closs, Emilie Raaum; Lyamouri, Miriam; Øymar, Knut Asbjørn Alexander et al. (2023). Regionale forskjeller i bruk av protonpumpehemmere hos barn. (external link)
• Sørensen, Karen Galta; Øymar, Knut Asbjørn Alexander; Dalen, Ingvild et al. (2022). Asthma, atopy and lung function in young adults after hospitalisation for bronchiolitis in infancy: Impact of virus and sex. (external link)
• Engan, Mette; Engeset, Merete Salveson; Sandvik, Lorentz et al. (2022). Left vocal cord paralysis, lung function and exercise capacity in young adults born extremely preterm with a history of neonatal patent ductus arteriosus surgery—A national cohort study. (external link)
• Bårdsen, Tonje; Røksund, Ola Drange; Benestad, Merete et al. (2022). Tracking of lung function from 10 to 35 years after being born extremely preterm or with extremely low birth weight. (external link)
• Mikalsen, Ingvild Bruun; Halvorsen, Thomas; Juliusson, Pétur Benedikt et al. (2021). Early life growth and associations with lung function and bronchial hyperresponsiveness at 11-years of age. (external link)
• Bjorland, Peder Aleksander; Ersdal, Hege Langli; Haynes, Joanna Clare et al. (2021). Tidal volumes and pressures delivered by the NeoPuff T-piece resuscitator during resuscitation of term newborns. (external link)
• Vatne, Anlaug; Klingenberg, Claus; Rettedal, Siren et al. (2021). Early-Onset Sepsis in Neonates - A Population-Based Study in South-West Norway From 1996 to 2018. (external link)
• Bjorland, Peder Aleksander; Ersdal, Hege Langli; Eilevstjønn, Joar et al. (2020). Changes in heart rate from 5 s to 5 min after birth in vaginally delivered term newborns with delayed cord clamping. (external link)
• Barstad, Bjørn; Henningsson, Anna J.; Tveitnes, Dag et al. (2020). Cerebrospinal fluid cytokines and chemokines in children with Lyme neuroborreliosis; pattern and diagnostic utility. (external link)
• Vatne, Anlaug; Klingenberg, Claus; Øymar, Knut et al. (2020). Reduced antibiotic exposure by serial physical examinations in term neonates at risk of early-onset sepsis. (external link)
• Sørensen, Karen Galta; Mikalsen, Ingvild Bruun; Neven, Axel Cornelis et al. (2020). Half of children with recurrent or chronic wet cough before three years of age were symptom-free by age seven. (external link)
• Bjorland, Peder Aleksander; Ersdal, Hege Langli; Øymar, Knut et al. (2020). Compliance with Guidelines and Efficacy of Heart Rate Monitoring during Newborn Resuscitation: A Prospective Video Study. (external link)
• Mikalsen, Ingvild Bruun; Byberg, Kristine Kjer; Forman, Michele R. et al. (2020). Adipokines in adolescence; the associations with lung function and atopy – A cross-sectional study. (external link)
• Aarthun, Antje; Øymar, Knut; Akerjordet, Kristin (2019). Parental involvement in decision-making about their child's health care at the hospital. (external link)
• Barstad, Bjørn; Tveitnes, Dag; Dalen, Ingvild et al. (2019). The B-lymphocyte chemokine CXCL13 in the cerebrospinal fluid of children with Lyme neuroborreliosis: associations with clinical and laboratory variables. (external link)
• Bjorland, Peder Aleksander; Øymar, Knut; Ersdal, Hege Langli et al. (2019). Incidence of newborn resuscitative interventions at birth and short-term outcomes: A regional population-based study. (external link)
• Sørensen, Karen Galta; Øymar, Knut; Dalen, Ingvild et al. (2019). Lung function and bronchial hyper-reactivity from 11 to 18 years in children with bronchiolitis in infancy. (external link)
• Engan, Mette; Vollsæter, Maria; Øymar, Knut et al. (2019). Comparison of physical activity and body composition in a cohort of children born extremely preterm or with extremely low birth weight to matched term-born controls: a follow-up study. (external link)
• Aarthun, Antje; Øymar, Knut; Akerjordet, Kristin (2019). Health professionals’ involvement of parents in decision-making in interprofessional practice at the hospital. (external link)
• Mikalsen, Ingvild Bruun; Dalen, Ingvild; Karlstad, Øystein et al. (2019). Airway symptoms and atopy in young children prescribed asthma medications: A large‐scale cohort study. (external link)
• Linde, Jørgen Erland; Perlman, Jeffrey M.; Øymar, Knut et al. (2018). Predictors of 24-h outcome in newborns in need of positive pressure ventilation at birth. (external link)
• Barstad, Bjørn; Quarsten, Hanne; Tveitnes, Dag et al. (2018). Direct molecular detection and genotyping of borrelia burgdorferi sensu lato in cerebrospinal fluid of children with lyme neuroborreliosis. (external link)
• Byberg, Kristine Kjer; Mikalsen, Ingvild Bruun; Eide, Geir Egil et al. (2018). The associations between weight-related anthropometrics during childhood and lung function in late childhood: A retrospective cohort study. (external link)
• Skromme, Kaia; Vollsæter, Maria; Øymar, Knut et al. (2018). Respiratory morbidity through the first decade of life in a national cohort of children born extremely preterm. (external link)
• Vollsæter, Maria; Halvorsen, Thomas; Markestad, Trond et al. (2018). Renal function and blood pressure in 11 year old children born extremely preterm or small for gestational age. (external link)
• Førsvoll, Jostein Andersen; Øymar, Knut (2018). The role of tonsillectomy in the Periodic Fever, Aphthous stomatitis, Pharyngitis and cervical Adenitis syndrome; A literature review. (external link)
• Mikalsen, Ingvild Bruun; Nassehi, Damoun; Øymar, Knut (2018). Vortex whistle and smart phone application for peak flow recordings in asthmatic children: A feasibility study. (external link)
• Mikalsen, Ingvild Bruun; Karlstad, Øystein; Furu, Kari et al. (2018). Forskrivning av legemidler mot astma til barn i perioden 2004–15. (external link)
• Popperud, Trine Haug; Boldingh, Marion; Brunborg, Cathrine et al. (2017). Juvenile myasthenia gravis in Norway: A nationwide epidemiological study. (external link)
• Bentsen, Mariann; Markestad, Trond; Øymar, Knut et al. (2017). Lung function at term in extremely preterm-born infants: A regional prospective cohort study. (external link)
• Øymar, Knut; Mikalsen, Ingvild Bruun; Crowley, Suzanne (2017). Protrahert bakteriell bronkitt hos barn. (external link)
• Byberg, Kristine Kjer; Øymar, Knut; Eide, Geir Egil et al. (2017). Exposure to preeclampsia in utero affects growth from birth to late childhood dependent on child's sex and severity of exposure: Follow-up of a nested case-control study. (external link)
• Linde, Jørgen Erland; Schulz, Jörn; Perlman, Jeffrey M. et al. (2017). The relation between given volume and heart rate during newborn resuscitation. (external link)
• Aarthun, Antje; Øymar, Knut; Akerjordet, Kristin (2017). How health professionals facilitate parents' involvement in decision-making at the hospital: A parental perspective. (external link)
• Linde, Jørgen Erland; Eilevstjønn, Joar; Øymar, Knut et al. (2017). Feasibility of a prototype newborn resuscitation monitor to study transition at birth, measuring heart rate and ventilator parameters, an animal experimental study. (external link)
• Barstad, Bjørn; Tveitnes, Dag; Noraas, Sølvi et al. (2017). Cerebrospinal Fluid B-lymphocyte Chemoattractant CXCL13 in the Diagnosis of Acute Lyme Neuroborreliosis in Children. (external link)
• Monsen, Anne Lise Bjørke; Vollsæter, Maria; Ueland, Per Magne et al. (2016). Increased bronchial hyperresponsiveness and higher asymmetric dimethylarginine levels after fetal growth restriction. (external link)
• Byberg, Kristine Kjer; Eide, Geir Egil; Forman, Michele R. et al. (2016). Body mass index and physical activity in early childhood are associated with atopic sensitization, atopic dermatitis and asthma in later childhood. (external link)
• Linde, Jørgen Erland; Schulz, Jörn; Perlman, Jeffrey M. et al. (2016). Normal newborn heart rate in the first five minutes of life assessed by dry-electrode electrocardiography. (external link)
• Vollsæter, Maria; Skromme, Kaia; Satrell, Emma Elsa Carolina et al. (2015). Children born preterm at the turn of the millennium had better lung function than children born similarly preterm in the early 1990s. (external link)
• Edwards, Alan Martin; Bibawy, Dalia; Matthews, Sharon et al. (2015). Long-term use of a 4% sodium cromoglicate cutaneous emulsion in the treatment of moderate to severe atopic dermatitis in children. (external link)
• Tveitnes, Dag; Øymar, Knut (2015). Gender differences in childhood lyme neuroborreliosis. (external link)
• Mikalsen, Ingvild Bruun; Skeiseid, Liliane Merete; Tveit, Line Merete et al. (2015). Decline in admissions for childhood asthma, a 26-year period population-based study. (external link)
• Førsvoll, Jostein Andersen; Janssen, Emilius Adrianus Maria; Møller, Ingegerd et al. (2015). Reduced number of CD8+ cells in tonsillar germinal centres in children with the periodic fever, aphthous stomatitis, pharyngitis and cervical adenitis syndrome. (external link)
• Øymar, Knut; Mikalsen, Ingvild Bruun; Furu, Kari et al. (2015). Prescription patterns of inhaled corticosteroids for preschool children - A Norwegian register study. (external link)
• Rettedal, Siren; Löhr, Iren Høyland; Bernhoff, Eva et al. (2015). Extended-spectrum β-lactamase-producing Enterobacteriaceae among pregnant women in Norway: Prevalence and maternal-neonatal transmission. (external link)
• Mikalsen, Ingvild Bruun; Halvorsen, Thomas; Øymar, Knut (2014). Blood eosinophil counts during bronchiolitis are related to bronchial hyper-responsiveness and lung function in early adolescence. (external link)
• Byberg, Kristine Kjer; Øglænd, Bjørn Edvin; Eide, Geir Egil et al. (2014). Birth after preeclamptic pregnancies: Association with allergic sensitization and allergic rhinoconjunctivitis in late childhood; a historically matched cohort study. (external link)
• Bigorgne, Amélie E.; Farin, Henner F.; Lemoine, Roxane et al. (2014). TTC7A mutations disrupt intestinal epithelial apicobasal polarity. (external link)
• Øymar, Knut; Bårdsen, Kjersti (2014). Continuous positive airway pressure for bronchiolitis in a general paediatric ward; a feasibility study. (external link)
• Mikalsen, Ingvild Bruun; Halvorsen, Thomas; Eide, Geir Egil et al. (2013). Severe bronchiolitis in infancy: Can asthma in adolescence be predicted?. (external link)
• Mikalsen, Ingvild Bruun; Halvorsen, Thomas; Øymar, Knut (2013). Exhaled nitric oxide is related to atopy, but not asthma in adolescents with bronchiolitis in infancy. (external link)
• Førsvoll, Jostein Andersen; Kristoffersen, Einar Klæboe; Øymar, Knut (2013). Elevated levels of CXCL10 in the Periodic Fever, Aphthous stomatitis, Pharyngitis and cervical Adenitis syndrome (PFAPA) during and between febrile episodes; an indication of a persistent activation of the innate immune system. (external link)
• Löhr, Iren Høyland; Rettedal, Siren; Natås, Olav Bjarte et al. (2013). Long-term faecal carriage in infants and intra-household transmission of CTX-M-15-producing Klebsiella pneumoniae following a nosocomial outbreak. (external link)
• Førsvoll, Jostein Andersen; Kristoffersen, Einar Klæboe; Øymar, Knut (2013). Incidence, clinical characteristics and outcome in Norwegian children with periodic fever, aphthous stomatitis, pharyngitis and cervical adenitis syndrome; a population-based study. (external link)
• Rettedal, Siren; Löhr, Iren Høyland; Natås, Olav Bjarte et al. (2013). Risk factors for acquisition of CTX-M-15 extended-spectrum beta-lactamase-producing Klebsiella pneumoniae during an outbreak in a neonatal intensive care unit in Norway. (external link)
• Rettedal, Siren; Löhr, Iren Høyland; Natås, Olav Bjarte et al. (2012). First outbreak of extended-spectrum beta-lactamase-producing Klebsiella pneumoniae in a Norwegian neonatal intensive care unit; associated with contaminated breast milk and resolved by strict cohorting. (external link)
• Mikalsen, Ingvild Bruun; Halvorsen, Thomas; Øymar, Knut (2012). The outcome after severe bronchiolitis is related to gender and virus. (external link)
• Tveitnes, Dag; Natås, Olav Bjarte; Skadberg, Øyvind et al. (2012). Lyme meningitis, the major cause of childhood meningitis in an endemic area: a population based study. (external link)
• Gilje, Ann Marit; Knudsen, Per Kristian; Øymar, Knut (2011). Ei ung jente med magesmerter. (external link)
• Røsvik, Alet Jenny; Øymar, Knut; Kvaløy, Jan Terje et al. (2009). Oxygen saturation in healthy newborns; influence of birth weight and mode of delivery. (external link)
• Tveitnes, Dag; Øymar, Knut; Natås, Olav B. (2009). Laboratory data in children with Lyme neuroborreliosis, relation to clinical presentation and duration of symptoms. (external link)
• Hagen, Inge; Øymar, Knut (2009). Pharmacological differences between once daily and twice daily gentamicin dosage in newborns with suspected sepsis. (external link)
• Øymar, Knut; Tveitnes, Dag (2009). Clinical characteristics of childhood Lyme neuroborreliosis in an endemic area of northern Europe. (external link)
• Røsvik, Atle; Øymar, Knut; Kvaløy, Jan Terje et al. (2009). Oxygen saturation in healthy newborns; influence of birth weight and mode of delivery. (external link)
• Byberg, Kristine; Øymar, Knut; Aksnes, Lage (2008). Fatty acids in cord blood plasma, the relation to soluble CD23 and subsequent atopy. (external link)
• Øymar, Knut; Tveitnes, Dag (2008). Økt forekomst av nevroborreliose hos barn. (external link)
• Øymar, Knut (2007). Allergivaksinasjon i Norge. (external link)
• Øymar, Knut; Kristoffersen, Einar Klæboe (2007). Periodisk feber-syndrom hos barn. (external link)
• Førsvoll, Jostein A.; Øymar, Knut (2007). C-reactive protein in the periodic fever, aphthous stomatitis, pharyngitis and cervical adenitis (PFAPA) syndrome. (external link)
• Øymar, Knut; Røsvik, Atle; Fossheim, Jan et al. (2007). Regelmessige episoder med høy feber hos en liten gutt. (external link)
• Tveitnes, Dag; Øymar, Knut; Natås, Olav B. (2007). Acute facial nerve palsy in children: How often is it Lyme borreliosis?. (external link)
• Øymar, Knut; Halvorsen, Thomas; Aksnes, Lage (2006). Mast cell activation and leukotriene secretion in wheezing infants. Relation to respiratory syncytial virus and outcome. (external link)
• Reindal, Lise; Øymar, Knut (2006). Hospital admissions for wheezing and asthma in childhood - are they avoidable?. (external link)
• Øymar, Knut; Aksnes, Lage (2005). Increased levels of urinary leukotriene E4 in children with severe atopic eczema/dermatitis syndrome. (external link)
• Halvorsen, Thomas; Skadberg, Brit; Eide, Geir Egil et al. (2005). Characteristics of asthma and airway hyper-responsiveness after premature birth. (external link)
• Aurivillius, M.; Øymar, Knut; Oxelius, V-A (2005). Immunoglobulin heavy G2 chain (IGHG2) gene restriction in the development of severe respiratory syncytial virus infection. (external link)
• Øymar, Knut; Aksnes, Lage (2005). Increased levels of urinary leukotriene E4 in children with severe eczema/dermatitis syndrome. (external link)
• Øymar, Knut; Aksnes, Lage (2004). Urinary 9 alpha,11 beta-prostaglandin F-2 in children with atopic eczema/dermatitis syndrome: An indicator of mast cell activation?. (external link)
• Engelsvold, David Hugo; Øymar, Knut (2003). Innleggelser for akutt astme hos barn. (external link)
• Engelsvold, David Hugo; Øymar, Knut (2003). Hospital admissions for childhood asthma in Rogaland, Norway from 1984 to 2000. (external link)
• Ellingsen, B; Ase, S; Øymar, Knut (2003). Forebygging av respiratorisk syncytalvirus-infeksjoner med pailvizumlab. (external link)
• Øymar, Knut; Havnen, Jakob; Halvorsen, Thomas et al. (2001). Eosinophil counts and urinary eosinophil protein X in children hospitalized for wheezing during the first year of life: prediction of recurrent wheezing. (external link)
• Øymar, Knut; Bjerknes, Robert (2001). Urinary eosinophil protein X in children with asthma: influence of atopy and airway infections. (external link)
• Øymar, Knut; Havnen, Jakob; Halvorsen, Thomas et al. (2001). Eosinophil counts and urinary eosinophil protein X in children hospitalize for wheezing during the first year of life: prediction of recurrent wheezing. (external link)
• Øymar, Knut; Lærdal, Åge; Bjerknes, Robert (2000). Soluble CD30 and CD23 in cord blood are not related to atopy in early childhood. (external link)
• Øymar, Knut; Bjerknes, Robert (2000). Urinary eosinophil protein X in children with atopic dermatitis: relation to atopy and disease activity. (external link)
• Øymar, Knut; Bjerknes, Robert (1998). Differential patterns of circulating adhesion molecules in children with bronchial asthma, and acute bronchiolitis. (external link)
• Øymar, Knut; Bjerknes, Robert (1998). Is serum eosinophil cationic protein in bronchiolitis a predictor of asthma?. (external link)
• Øymar, Knut; Elsayed, Said; Bjerknes, Robert (1997). Serum eosinophil cationic protein and interleukin-5 in childeren with bronchial asthma and acute bronchiolitis. (external link)
• Øymar, Knut; Fluge, Gjermund; Rosendahl, Karen (1993). Residiverende abdominalsmerter. En prospektiv undersøkelse. (external link)

Feature article

• Øymar, Knut Asbjørn Alexander; Tjora, Erling; Størdal, Ketil (2025). Ammende trenger sjelden å slutte med kumelk. (external link)
• Øymar, Knut (2012). Bruk av inhalasjonssteroider hos førskolebarn. (external link)

Reader opinion piece

• Sørensen, Karen Galta; Øymar, Knut Asbjørn Alexander; Halvorsen, Thomas et al. (2023). Blood eosinophils during bronchiolitis were not associated with adult asthma in a Norwegian cohort study. (external link)
• Parr, Christine Louise; Nystad, Wenche; Karlstad, Øystein et al. (2022). Ten-year trends of national healthcare costs of asthma, allergic rhinitis, and atopic eczema in 3 million Norwegians. (external link)
• Øymar, Knut Asbjørn Alexander; Karlstad, Øystein; Størdal, Ketil (2021). Har anbefalinger om endring av behandling effekt?. (external link)
• Sørensen, Karen Galta; Øymar, Knut Asbjørn Alexander; Halvorsen, Thomas et al. (2020). Reply to Korppi and Riikonen. (external link)
• Øymar, Knut; Mikalsen, Ingvild Bruun; Crowley, Suzanne (2018). K. Øymar og medarbeidere svarer. (external link)
• Øymar, Knut; Mikalsen, Ingvild Bruun; Nag, Torbjørn et al. (2017). Systemiske steroider til førskolebarn med symptomer fra nedre luftveier. (external link)
• Mikalsen, Ingvild Bruun; Halvorsen, Thomas; Øymar, Knut (2013). The optimal management for patients (Letter). (external link)
• Tveitnes, Dag; Hjetland, Reidar; Øymar, Knut (2013). Tolking av serologiske testar. (external link)

Academic literature review

• Førsvoll, Jostein Andersen; Kristoffersen, Einar Klæboe; Øymar, Knut (2019). The immunology of the periodic fever, aphthous stomatitis, pharyngitis and cervical adenitis syndrome; what can the tonsils reveal. A literature review.. (external link)
• Mikalsen, Ingvild Bruun; Davis, Peter; Øymar, Knut (2016). High flow nasal cannula in children: A literature review. (external link)
• Øymar, Knut; Skjerven, Håvard Ove; Mikalsen, Ingvild Bruun (2014). Acute bronchiolitis in infants, a review. (external link)
• Øymar, Knut; Halvorsen, Thomas (2009). Emergency presentation and management of acute severe asthma in children. (external link)
• Øymar, Knut (2000). Bakteriell trakeitt hos barn. (external link)
• Øymar, Knut (1997). Diskitt hos barn. Beskrivelse av tilstanden illustrert ved to eksempler. (external link)

Doctoral dissertation

• Bentsen, Mariann; Halvorsen, Thomas; Markestad, Trond et al. (2018). Tidal breathing parameters in extremely premature infants. Feasibility and clinical utility of electromagnetic inductance plethysmography. (external link)
• Byberg, Kristine Kjer; Øglænd, Bjørn Edvin; Øymar, Knut (2017). An epidemiological study on the associations between preeclampsia exposure, growth and physical activity in preschool age and subsequent allergy, asthma and lung function in late childhood. (external link)
• Rettedal, Siren Irene; Øymar, Knut (2016). Extended-spectrum beta-lactamase producing Enterobacteriaceae in neonates; Hospital outbreak, colonization, transmission and persistence. (external link)
• Førsvoll, Jostein Andersen; Øymar, Knut (2015). The Periodic Fever, Aphthous stomatitis, Pharyngitis and cervical Adenitis syndrome in children. Clinical and immunological aspects. (external link)
• Øymar, Knut (2001). Eosinophil inflammation in children with asthma, wheezing and atopic dermatitis. (external link)

Poster

• Engeseth, Merete Salveson; Clemm, Hege Synnøve Havstad; Røksund, Ola Drange et al. (2015). Better respiratory outcomes for extremely preterm born children.. (external link)
• Vollsæter, Maria; Clemm, Hege Synnøve Havstad; Thorsen, Einar et al. (2014). Alveolar nitric oxide(NO)in children born extremely preterm (EP).. (external link)

Academic lecture

• Øymar, Knut (2005). Palivizumab ved lungesykdommer, contra. (external link)
• Øymar, Knut (2005). Allergivaksinering, status i Norge. (external link)
• Øymar, Knut (2005). Periodisk febersyndrom hos barn. (external link)

See a complete overview of publications in Cristin.