Many conditions, medicines, and diseases interfere with the ability to heal or fight infection. Your child may be at risk for a more serious problem if he or she has any of the following. Be sure to tell your child's health professional.

Conditions

• Newborn up to 3 months of age
• Problems or conditions present since birth (congenital)
• Premature birth or delayed growth and development
• Travel outside the country or exposed to immigrants or nonnative people
• An animal, insect, or tick bite in the past 6 weeks
• Surgery to remove the spleen

Medicines

• Antibiotics
• Blood-thinning medicines, such as warfarin, heparin, and aspirin
• Corticosteroids, such as prednisone
• Medicines to prevent organ transplant rejection
• Medicines used to treat cancer (chemotherapy)
• Radiation therapy

Diseases

• Asthma
• Cancer
• Cystic fibrosis
• Diabetes
• History of seizures
• Human immunodeficiency virus (HIV) infection
• Idiopathic thrombocytopenic purpura (ITP)
• Juvenile rheumatoid arthritis
• Kidney disease
• Lymphoma
• Malaria
• Malnutrition
• Sickle cell disease