Sarah Forgie is a pediatric infectious disease physician at the Stollery Children’s Hospital and professor in the University of Alberta’s Department of Pediatrics
Sheela Xavier has 5 years of clinical experience in India treating infectious diseases in children, particularly measles cases presenting with Koplik spots.
In 2000, endemic measles was declared eliminated in North America because of high levels of herd immunity thanks to an effective measles vaccine. However, measles remains endemic in other parts of the world, and with international travel, immigration and international adoptions, North Americans who are unvaccinated or inadequately vaccinated remain at risk for the disease. For example, in an ongoing measles outbreak in the United States and Canada that has been linked to a theme park, most of the patients infected were either unvaccinated or inadequately vaccinated.
Physicians must remain cognizant that a red rash with cough, coryza and conjunctivitis may be measles in those with epidemiological links. However, it is possible to recognize measles before the red rash appears by looking for Koplik spots. Recognition of this sign is hindered because most North American physicians have never seen measles. However, Koplik spots are pathognomonic for measles and should prompt isolation of the patient, and postexposure prophylaxis of susceptible contacts should be instituted to prevent further transmission and halt outbreaks.
We recently saw a child who had epidemiologic links to a patient with measles, and we found Koplik spots in her mouth. As Koplik stated, they had the appearance of “bluish, white 2–3 mm grains of salt on a red background on the buccal mucosa.” Our patient’s case prompted us to search into the history of the physical sign.
We found that Koplik was not the first to describe these lesions, but he was the first to emphasize that they were pathognomonic of measles. As far as we know, John Quier, a physician in Jamaica, gave the earliest known description of the spots in 1774. “But the most certain diagnostic of the disease in its beginning (and which I do not remember to have found mentioned by any author that I have met with), was the appearance of the white aphthous specks about the gums; which were always visible several days before the eruption, and not unfrequently before the fever began.” In 1802, Dr. Richard Hazeltine of Berwick, Maine, described “a pale miliary eruption” in the internal fauces and gums that appeared before the skin eruption. In 1881, a German internist Christian Gerhardt described, “whitish material mimicking desquamated epithelium on the inner cheek” and a few years later, in 1885, a Danish physician, Nikolaj Flindt described identical lesions on the hard and soft palate. In 1895, Russian physician Nil Filatov described “stomatitis morbillosa” as a precursor to the measles rash and until recently, the enanthem was called “Filatov sign” in Russia. A Russian textbook from 1966 stated “In the Soviet Union this symptom is known as the Filatov sign. The same sign was described somewhat later by an American doctor, Koplik. Notwithstanding the priority of the Russian doctors, the sign is known in foreign (and in prerevolutionary literature) as Koplik’s spots.”
In 1896, 1898 and 1899, American pediatrician Henry Koplik wrote three articles about the lesions. “It is indeed very late in the day to describe something connected with the diagnosis of the exanthemata. It will be seen from what follows that one of the most, if not the most, reliable sign of the invasion of measles has fully failed to receive due attention. My experience leads me to believe that the sign to be described as fairly ignored. This has led me to describe it here … The importance of making a positive diagnosis of measles cannot be overestimated … A thorough understanding of the eruption on the buccal mucous membrane will aid in separating an invading measles from a massive eruption resembling measles … Any positive sign of the invasion of any infectious or contagious disease is a step to proper isolation and prophylactic hygiene.”
So, even though Koplik was not the first to describe these lesions, it seemed to be a combination of factors — his description of the pathognomonic sign that permitted diagnosis and therefore patient isolation before the skin rash appeared, and his persistence in educating the profession about the sign — that led to the enanthem being given the name “Koplik spots.”
A recent (2019) Japanese study contradicts a pathognomonic value of Koplik spots to the measles virus.
This study not only suggests, in my opinion, it offers strong evidence that Koplik spots are overrated in MV diagnosis.