Differential Diagnosis for Fever and Rash in Pediatrics
Single Most Likely Diagnosis
- Viral Exanthem: This is the most common cause of fever and rash in children, often due to viruses such as enterovirus, adenovirus, or respiratory syncytial virus. The rash can vary in appearance and is usually accompanied by other symptoms like cough, runny nose, or sore throat.
Other Likely Diagnoses
- Urinary Tract Infection (UTI): Especially in younger children, UTIs can present with fever and rash, among other symptoms. The rash might not be directly related to the infection but could be a sign of the child's overall illness.
- Roseola: Caused by human herpesvirus 6 (HHV-6) or human herpesvirus 7 (HHV-7), roseola is characterized by a high fever followed by a rash once the fever resolves. It's common in children under two years old.
- Impetigo: A bacterial skin infection that can cause a rash, often accompanied by fever. It's contagious and can spread through direct contact with the lesions.
Do Not Miss Diagnoses
- Meningococcemia: Although less common, meningococcemia is a life-threatening condition caused by Neisseria meningitidis. It can present with fever, rash (often petechial or purpuric), and signs of meningitis or sepsis. Prompt recognition and treatment are crucial.
- Kawasaki Disease: An acute febrile illness of childhood that can lead to coronary artery aneurysms if not treated. It's characterized by fever, rash, conjunctivitis, cervical lymphadenopathy, and changes to the lips and oral cavity.
- Stevens-Johnson Syndrome/Toxic Epidermal Necrolysis: Severe skin and mucous membrane disorders, usually a reaction to medication or infection. They can present with fever and a rash that progresses to blistering and peeling of the skin.
Rare Diagnoses
- Juvenile Idiopathic Arthritis (JIA): Can present with fever and rash, among other symptoms like joint pain and swelling. The rash is often evanescent and may appear during febrile episodes.
- Lyme Disease: Caused by Borrelia burgdorferi, transmitted by tick bites. It can present with a distinctive "bull's-eye" rash (erythema migrans), fever, and other symptoms.
- Rocky Mountain Spotted Fever: A tick-borne illness caused by Rickettsia rickettsii, characterized by fever, headache, and a rash that typically appears a few days after the onset of fever.