Not all fever and rash in Singapore is Zika…

A middle-aged man presented (way before the current Zika outbreak) with high fever for 5 days, associated with runny nose and sore throat. On the third day of illness, he developed a rash which started from his face before spreading to his body and limbs. He also developed bilateral red and painful eyes at this point.

He had taken only medications for symptomatic relief from his GP (no antibiotics), and denied any recent unprotected sexual intercourse. The last trip was to a regional metropolis 2 weeks prior to fever onset, but there was no contact history of note.

Close up photo of the back, showing a predominantly maculopapular rash

A rather bad photo of the oral cavity and palate

Question: What is the diagnosis and how should it be confined?

[Updated 10 September 2016]

The diagnosis here is measles with a Koplik’s spot shown in the photo of the oral cavity. This is technically a clinical diagnosis, but due to the paucity of cases in Singapore, relatively few clinicians are likely to be confident in diagnosing this based on history and physical examination alone. Measles serology is unlikely to be positive within the first few days of illness, hence the way to confirm it would be to take a throat swab and send it for measles PCR test.