Dr. Chapa’s Clinical Pearls: MEASLES 101! What to Know

Release Date: February 24, 2025

In this comprehensive episode of Dr. Chapa’s Clinical Pearls, Dr. Smith delves into the current measles outbreak in the United States, offering essential insights for healthcare providers, particularly those in obstetrics and gynecology. The episode provides a detailed overview of measles’ clinical presentation, implications for pregnant patients, post-exposure prophylaxis, and best practices for managing and preventing the spread of this highly contagious viral illness.

Current Measles Outbreak Overview

The episode begins with Dr. Smith referencing a recent CBS News report on the measles outbreak, highlighting the surge to nearly 100 cases primarily in Texas and an increasing number in New Mexico.

Dr. Smith [00:27]: "This is making progress right now. Is the U.S. measles outbreak. Yes, it's related right now to West Texas and parts of eastern New Mexico."

Dr. Smith emphasizes the importance of recognizing that infectious diseases like measles can rapidly spread beyond their initial locations due to high mobility and travel rates.

Measles Clinical Presentation

Symptoms and Signs

Dr. Smith revisits fundamental clinical signs of measles, ensuring healthcare providers can accurately identify the disease.

Dr. Smith [02:45]: "Measles is an acute viral respiratory illness that comes with fever, malaise, cough, there's conjunctivitis."

Koplik Spots

A key diagnostic feature discussed is the presence of Koplik spots—small white lesions with a red halo inside the mouth, typically appearing one to two days before the measles rash.

Dr. Smith [05:30]: "Those are called Koplik spots. You all remember that? K, O, P, L, I, K, Koplik spots."

He underscores the importance of examining the oral mucosa to identify these spots, which are often located near the lower molars.

Dr. Smith [07:15]: "Look in the lower parts of the oral mucosa by the molars. All right, so those are Koplik spots."

Rash Characteristics

Contrary to some viral exanthems, the measles rash progresses from the head downward.

Dr. Smith [09:45]: "The rash spreads from the head, then it goes to the trunk and then it goes to the lower extremities. So head, trunk, legs, head, trunk, legs."

This top-down progression is a critical differentiator for diagnosing measles.

Contagious Period

Measles is highly contagious, with patients being infectious from four days before to four days after the rash appears.

Dr. Smith [12:10]: "Patients are typically contagious from about four days before the rash to four days after the rash appears."

Measles in Pregnancy

Risks to Mother and Fetus

Measles poses significant risks during pregnancy, including increased chances of hospitalization, pneumonia, encephalitis, hepatitis, miscarriage, stillbirth, low birth weight, and preterm delivery.

Dr. Smith [14:20]: "Miscarriage has an odds ratio of around 5... it can cause stillbirth, it can cause low birth weight, it can cause preterm delivery."

For the fetus, measles can lead to neonatal complications such as hearing loss, encephalitis, and neonatal death, although it does not increase the risk of congenital malformations.

Dr. Smith [15:50]: "There does not seem to be an increase in the risk of congenital malformations... it's not a structural issue."

ACOG Guidance and Prenatal Care

Following ACOG’s practice advisory from March 2024, Dr. Smith recommends that clinicians assess measles immunity as part of prenatal care, similar to rubella and varicella screenings.

Dr. Smith [13:30]: "We should be checking for measles immunity, just like we do for rubella, and we should also do that for varicella."

He highlights the importance of preconception consultations to ensure immunity, noting the challenges due to limited coverage before pregnancy.

Post-Exposure Prophylaxis

For Pregnant and Non-Pregnant Women

Dr. Smith outlines the CDC and ACOG recommendations for post-exposure prophylaxis (PEP) for individuals exposed to measles who lack documented immunity.

Dr. Smith [17:00]: "Pregnant and non-pregnant women exposed to measles who cannot readily show that they have evidence of immunity should be offered post exposure prophylaxis."

For pregnant women, intravenous immunoglobulin (IVIG) at a dose of 400 mg/kg should be administered within six days of exposure.

Dr. Smith [17:40]: "IVIG at 400. Is that weird or what? How many times? ... 400 milligrams per kilo within six days of measles exposure for IVIG."

Non-pregnant individuals should receive the MMR vaccine within three days of exposure or IVIG within six days, but not both.

Dr. Smith [16:50]: "Either MMR within three or IVIG within six days."

Isolation and Preventive Measures

For those exposed, Dr. Smith advises isolation of the infected individual, frequent hand washing, respiratory precautions, and masking to prevent further transmission.

Diagnosis and Testing

When measles infection is suspected, Dr. Smith recommends comprehensive testing:

• Oropharyngeal Swabs: For PCR testing.
• Blood Samples: For serology.
• Urine Samples: For viral RNA by PCR.

Dr. Smith [17:00]: "Do nasopharyngeal urine and blood for viral RNA through PCR."

He stresses not to overlook oral examinations, as early detection of Koplik spots is crucial.

Treatment and Management

Management of active measles infection primarily involves supportive care, including:

• Antipyretics: To manage fever.
• Isolation Measures: To prevent contagion.
• Supportive Therapies: Addressing symptoms as needed.

While the efficacy of IVIG for treating active infections is debated, Dr. Smith notes that it can be administered without harm.

Dr. Smith [16:05]: "It doesn't hurt. And mainly the treatment, the management is more supportive."

Postpartum Considerations

After delivery, Dr. Smith advises assessing the newborn for measles, especially if the mother developed the rash within ten days of delivery, which could indicate vertical transmission risks.

Dr. Smith [16:50]: "There is a risk of congenital measles. This has an increased risk for the child of increased mortality... delivering within 10 days of this rash could be potentially bad for the child."

He also recommends offering the MMR vaccine to postpartum patients who lack immunity.

Dr. Smith [17:30]: "Offer them MMR... MMR can also be given for those without evidence of prior immunity."

Clinical Pearls: Key Takeaways

1. Examination Focus: Always examine the oral mucosa for Koplik spots in suspected measles cases.
2. Rash Progression: Recognize that measles rash spreads from the head downwards.
3. Contagious Period: Patients are contagious from four days before to four days after the rash onset.
4. Post-Exposure Prophylaxis: Administer IVIG to pregnant women within six days post-exposure and MMR or IVIG to non-pregnant individuals within the appropriate timeframe.
5. Prenatal Screening: Incorporate measles immunity assessment into prenatal care protocols.
6. Postpartum Vaccination: Ensure postpartum patients receive the MMR vaccine if not previously immune.

Notable Quotes

• Dr. Smith [00:27]: "What happens in one place does not stay there. So this is the problem."
• Dr. Smith [05:30]: "You all remember that? K, O, P, L, I, K, Koplik spots."
• Dr. Smith [12:10]: "Patients are typically contagious from about four days before the rash to four days after the rash appears."
• Dr. Smith [17:00]: "Pregnant and non-pregnant women exposed to measles who cannot readily show that they have evidence of immunity should be offered post exposure prophylaxis."
• Dr. Smith [17:30]: "Offer them MMR... MMR can also be given for those without evidence of prior immunity."

Dr. Smith concludes the episode by reinforcing the critical aspects of measles management, emphasizing the importance of vigilance, timely prophylaxis, and comprehensive prenatal care to mitigate the risks associated with this highly contagious disease.