A 13-month-old baby has a fever for no apparent reason.

Fever, also known as pyrexia, in a 1-year-and-1-month-old baby without apparent cause may be related to conditions such as roseola infantum, pediatric cold, chronic pneumonia, and other diseases. It is important to promptly identify the underlying cause and initiate treatment under medical guidance. Specific analyses are as follows:

1. Roseola Infantum

This condition occurs when the baby is infected with human herpesvirus type 6 or 7, leading to an exanthematous febrile illness. This causes a sudden rise in body temperature, accompanied by symptoms such as rash and eyelid swelling. If body temperature exceeds 38.5°C, medications such as acetaminophen tablets, ibuprofen sustained-release capsules, or Xiao'er Chai Gui Tui Re Granules may be administered under medical supervision to achieve antipyretic effects.

2. Pediatric Cold

Due to their young age and relatively weak immune systems, babies are susceptible to viral infections from pathogens like rhinovirus or respiratory syncytial virus, which can easily lead to respiratory tract infections. Symptoms include nasal congestion, runny nose, and fever. It is recommended to drink plenty of warm water. In severe cases, consult a doctor for administration of antiviral oral solutions, Pudilan Xiaoyan Oral Liquid, or Xiao'er Chuqiao Qingre Granules.

3. Chronic Pneumonia

If the lung tissue of the baby becomes infected by pathogens, it may result in persistent fever accompanied by coughing, sputum production, and rapid breathing. After onset, treatment under medical guidance may include antibiotics such as amoxicillin capsules, cefaclor granules, or compound zinc bromelain granules, along with appropriate supportive care.

In addition, fever could also be caused by factors such as Kawasaki disease, rheumatic fever, or leukemia. Immediate medical attention is necessary upon symptom onset, and attention should be paid to maintaining cleanliness and hygiene within the indoor environment.