Differential Diagnosis for Rash on Face after Fever
Single Most Likely Diagnosis
- Viral Exanthem: This is the most common cause of a rash after a fever, especially in children. Viral exanthems are characterized by a rash that appears in conjunction with a fever and can be caused by a variety of viruses, including enteroviruses, adenoviruses, and parvovirus B19.
Other Likely Diagnoses
- Kawasaki Disease: An acute febrile illness that primarily affects children, characterized by a rash, fever, conjunctivitis, and lymphadenopathy. The rash can vary in appearance but often starts on the face.
- Measles: A highly contagious viral infection that starts with a fever, followed by a characteristic rash that begins on the face and spreads to other parts of the body.
- 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 that can appear on the face and trunk after the fever resolves.
Do Not Miss Diagnoses
- Meningococcemia: A severe infection caused by Neisseria meningitidis, which can present with a fever and a rash. The rash can start as small, pink spots that quickly turn into purple spots or large bruises, and it often appears on the face and extremities. This condition is life-threatening and requires immediate medical attention.
- Rocky Mountain Spotted Fever (RMSF): A tick-borne illness caused by Rickettsia rickettsii, characterized by fever, headache, and a rash that typically starts on the wrists, ankles, palms, and soles but can also appear on the face.
- Stevens-Johnson Syndrome (SJS) and Toxic Epidermal Necrolysis (TEN): Severe skin and mucous membrane disorders, usually a reaction to medication or infection, characterized by a rash, blisters, and skin peeling. These conditions can be life-threatening and require immediate medical intervention.
Rare Diagnoses
- Erythema Infectiosum: Caused by parvovirus B19, this condition is more commonly known as "fifth disease" and is characterized by a distinctive "slapped-cheek" rash on the face, followed by a lacy rash on the body.
- Scarlet Fever: A bacterial illness caused by group A Streptococcus, characterized by a bright red rash that covers most of the body, a red, bumpy tongue (strawberry tongue), and a fever. The rash can start on the face and spread to other areas.