What is the reason for a child to have a fever for a week?

Generally, children's fever will get better within one or two days. Some physical cooling treatment can greatly improve the series of symptoms caused by their fever. However, if the child has had a fever for about a week, it is not normal. At this time, drug treatment must be taken. Long-term fever will affect the normal development of their brain cells.

1. Short-term fever (fever < 2 weeks)

Short-term fever in pediatrics is mostly caused by infection, and generally has a good prognosis or is a self-limited disease. However, fever may also be an early manifestation of critically ill children, especially children with severe symptoms of poisoning such as mental depression, drowsiness, and pale complexion. Attention should be paid to the child's medical history, history of contact with infectious diseases, and the presence or absence of symptoms and signs of respiratory, digestive, urinary, nervous and other systems, as well as the presence or absence of rash, petechiae, jaundice, anemia, lymphadenopathy, hepatosplenomegaly, and local infection foci.

2. Long-term fever (fever ≥ 2 weeks)

(1) Infectious fever

1) Respiratory system infections are the most common, with pathogens including viruses, mycoplasmas, bacteria and tuberculosis;

2) Other system infections: intestinal infection, urinary system infection, central nervous system infection (encephalitis, meningitis), cardiovascular system infection (such as infective endocarditis, pericarditis), hepatobiliary system infection (such as hepatitis, cholangitis, liver abscess, etc.);

3) Systemic infections such as sepsis, tuberculosis, typhoid, paratyphoid, typhus, brucellosis, Epstein-Barr virus infection, cytomegalovirus infection, Lyme disease, leptospirosis, malaria, kala-azar, schistosomiasis and fungal infections;

4) Abscess or localized infection such as osteomyelitis, perinephric abscess, subphrenic abscess, appendiceal abscess, perianal abscess, etc.

(2) Non-infectious fever

1) Juvenile rheumatoid arthritis is the most common rheumatic disease. In recent years, as streptococcal infections have been promptly controlled, rheumatic fever has become less common. Other rheumatic diseases that cause fever include systemic lupus erythematosus, polyarteritis nodosa, Kawasaki disease, serum sickness, dermatomyositis, nodular nonsuppurative panniculitis, Wegener's malignant granulomatosis, and angioimmunoblastic lymphadenopathy.

2) Malignant tumors with tissue destruction or necrosis, with leukemia being the most common, and others including malignant lymphoma (including Hodgkin's and non-Hodgkin's lymphoma), neuroblastoma, malignant histiocytosis, Langerhans' histiocytosis and Ewing's sarcoma; large-area burns, after major surgery, internal bleeding absorption process, vascular embolism, etc.

3) Excessive heat production or reduced heat dissipation Excessive heat production is seen in hyperthyroidism, status epilepticus, and adrenal hyperfunction; reduced heat dissipation is seen in generalized dermatitis, massive water loss, blood loss, heat stroke, congenital ectodermal dysplasia, and excessive wrapping of newborns.

4) Diseases of the hypothalamic temperature regulation center such as skull injury, cerebral hypoplasia, intracranial tumors, subarachnoid hemorrhage, heat stroke, toxic encephalopathy, sequelae of encephalitis and diencephalic lesions.