NCIthesaurus has symptom respiratory system disease croup MESH:D003440 DOID:9395 NCI:C26735 A respiratory system infectious disease that involves inflammation, edema, and subsequent obstruction of the larynx, trachea, and bronchi. The disease is caused by viruses, bacteria, allergies and inhaled irritants. It is marked by episodes of difficult breathing and hoarse metallic cough in infants and young children. Croup is caused by parainfluenza virus (types 1 and 2), Influenza A and B viruses, Measles virus, adenovirus, respiratory syncytial virus, Staphylococcus and Streptococcus. UMLS_CUI:C0010380 ICD9CM:464.4 ICD10CM:J05.0 Croup syndrome Laryngotracheobronchitis acute Obstructive Laryngitis acute laryngotracheobronchitis disease_ontology SNOMEDCT_US_2025_09_01:71186008 cough