So measles has different signs and symptoms and these present in sequential states over 2-3 weeks.
The communicable period is about 8 days in total from 4 days before the rash appears
and ends after the rash has been present for about 4 days.
The first phase is the infection and incubation and this is about 10-14 days.
This is where your patient is asymptomatic.
In the second phase, this is non-specific.
It lasts 2-3 days and your patient will present as though they have a cold.
They'll have mild to moderate fever, cough, coryza which is a runny nose, and conjunctivitis.
We think of these as the 3 Cs. Next, the patient will have acute illness and rash.
They will develop a small, maculopapular, splotchy rash
and it's gonna spread in a cephalocaudal pattern.
This means it spreads from the head and neck down the body.
The patient will also have a very high fever, often 40 degrees or 104 degrees Farenheit.
And then as the rash recedes, it's gonna start receding from the face.
Here we see the classic signs and symptoms of measles.
Remember, it has a high fever.
The 3 Cs which are cough, coryza, and conjunctivitis.
A rash with cephalocaudal spread and Koplik spots.
Here we see those Koplik spots.
These are small, white spots on the insides of the cheeks opposite the molars.
So these are really hard to see.
Often when I'm assessing a child that I'm worried might have measles,
I'm trying to do a full exam and these children sometimes are thrashing
and they don't wanna open their mouth.
And these are very small spots in the mouth so if you see them,
that's helpful to help you diagnose measles
but if you can't see them, the patient can still have measles.
The patient's rash is gonna be a generalized red maculopapular rash that again,
is gonna spread from the hairline, the back of the ears,
and the head down to the neck, and then down the body.
Next we obtain a medical history and due to the potential for spread,
patients who present to the clinic for evaluation of measles are asked to call first
and actually remain in their car.
We actually go out to the patient's car and begin screening them and assessing them,
and doing any testing as needed.
And this will prevent the exposure and contamination of the entire clinic and the patients inside.
Next you'll review the patient's immunization status
and this is to exclude other causes of their fever and rash.
You're gonna be sure that they've had their MMR and one dose of MMR is 93% effective against measles.
If the patient has had 2 doses of MMR, they're 97% protected.
Next, you do the physical exam and this starts with looking at the patient's vital signs.
Next, you'll do a full head, eyes, ears, nose, throat exam.
You'll move down and do a cardiac and respiratory exam, and you'll do a full inspection of the skin.
Now remember, measles is a notifiable condition.
You have to notify the Health Department about any suspected cases.
So how do we diagnose measles?
Well, we wanna know that the patient has had a fever of at least 3 days
and they also need to have at least one of the following symptoms: a cough, coryza, or conjunctivitis.
And then you're gonna also look in the patient's mouth and look for these Koplik spots
and that is actually diagnostic of measles.
If you see these, you can be pretty sure the patient has measles.
If you have a patient you're suspecting might have measles, lab testing is strongly recommended.
This patient's going to have positive measles IgM antibodies and these show up in the acute phase.
You can also check the patient's urine and a measles virus RNA
can be detected in the respiratory secretions.
So what are some risk factors that are gonna increase your clinical suspicion for measles?
Well, the first is if the patient is unvaccinated.
Also, patients with recent international travel and patients with a known vitamin A deficiency.
So here's our diagnostic workup.
A patient presents and they have a fever.
They also have a rash and then they need one of those three: cough, coryza, or conjunctivitis.
Next, you'll progress to getting your lab samples
and you need to consult with your local health department and even your state health department
to see which test is recommended because based on the duration of the patient's symptoms,
they're gonna recommend different diagnostics.
And when you send these labs in, it's going to be a delay.
It's gonna be a 2-4 day turnaround so the patient needs to be isolated either until all of their test are negative,
maybe their fever and rash and cough, conjunctivitis and coryza
was caused by something else, or until 4 days after their rash has presented.
Whichever is first.