Differential Diagnosis for Rash of Measles vs Dengue
- Single most likely diagnosis
- Measles: Given the mention of a rash similar to measles, it's reasonable to consider measles as a primary diagnosis, especially in areas with low vaccination rates or during outbreaks. Measles is characterized by a morbilliform rash, fever, cough, runny nose, and conjunctivitis.
- Other Likely diagnoses
- Dengue Fever: Dengue can present with a rash, fever, and severe flu-like symptoms, making it a plausible alternative diagnosis, especially in endemic areas. The rash in dengue fever can appear early in the course of the disease.
- Rubella (German Measles): Although less common due to vaccination, rubella can cause a rash similar to measles but typically milder, along with fever and lymphadenopathy.
- Viral Exanthems: Various viral infections can cause rashes that might resemble measles or dengue, including enteroviruses, adenoviruses, and parvovirus B19.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Meningococcemia: This bacterial infection can cause a rash (petechial or purpuric) and has a high mortality rate if not treated promptly. It's crucial to consider, especially if the patient has a severe headache, stiff neck, or other signs of meningitis.
- Rocky Mountain Spotted Fever (RMSF): A tick-borne illness that can present with a rash, fever, and headache. It's critical to diagnose early due to its potential severity and the need for prompt antibiotic treatment.
- Rare diagnoses
- Scarlet Fever: Caused by Group A beta-hemolytic streptococci, it presents with a rash (like a sunburn), fever, and a "strawberry tongue." While not as common as other diagnoses, it's an important consideration due to its potential for complications if untreated.
- Kawasaki Disease: An acute febrile illness of childhood characterized by a rash, fever, conjunctivitis, and changes to the lips and oral cavity. It's a rare but important diagnosis due to its potential to cause coronary artery aneurysms if not treated.