SINGAPORE - Some time back, I found myself down with a high fever, with my body regularly hitting temperatures above 38 deg C. 

At the time I had no idea what I had caught as I had no other symptoms, and paracetamol did not appear to help lower my temperature. 

An antigen rapid test kit showed it was not Covid-19, and the general practitioner I consulted suspected it was a throat infection of some sort. 

Four days after I first came down with the fever, I could feel uncomfortable sores developing in my mouth. 

It was then that I finally realised what I had caught – my son’s herpangina, which is an infectious condition where one develops blisters and ulcers in the mouth.

Herpangina is closely related to the better-known hand, foot and mouth disease (HFMD), as both conditions are caused by the same group of viruses belonging to the Coxsackie and enterovirus family.

The infection usually involves the back of the soft palate, causing a sore throat and pain on swallowing food or fluids, and is often accompanied by a high fever.

Herpangina is different from HFMD in that the latter “involves blisters and ulcers over the hands and feet, on top of oral sores and fever”, Fullerton Health deputy medical director Marcus Lee told the Straits Times.

There were 4,098 cases of HFMD in Singapore in 2022, according to the Ministry of Health’s weekly infectious diseases bulletin, which does not track herpangina cases. 

There are currently no treatments or vaccines for either HFMD or herpangina.

Patients are treated for their symptoms, but must otherwise let the disease resolve itself.

Both diseases most commonly affect children below the age of 10, Dr Lee added. 

“Adults are less commonly affected, but have a higher risk if they come into close contact with infected children. For example, if they have infected children in the household, or if they work with young children,” he said. 

As a parent, I was fairly familiar with both diseases, with both my children having caught both highly contagious diseases multiple times. 

Still, despite often taking care of them on the days when they would have to stay home from school or childcare after getting infected, I had never caught either HFMD or herpangina – until now. 

I thought I knew what to expect. 

During both my boys’ multiple encounters with HFMD and herpangina, they had fevers for a few days but were otherwise active and made full recoveries within a week. 

I, on the other hand, had a high fever for almost a week, with my temperature not coming down despite taking medication every few hours.

I felt weak and lethargic, and spent most of my time curled up in bed. 

Of course, having caught a highly contagious disease, I had to miss out on several social engagements – visiting my parents, going to the mosque and meeting an old friend who had flown in from overseas. 

I had to take medical leave from work and miss out on a number of assignments I had been tasked with (okay, maybe this part was not that bad). 

Even once my fever had subsided, the sores remained, and I felt out of sorts for another week.

As far as I could tell, there were only a handful of sores in my mouth, but they were causing me a lot of distress. 

Even eating something soft and inoffensive like tau huay (soya bean curd) – which might have been an ideal, palatable choice were I having a sore throat – felt like I might as well have been eating a piece of sandpaper, for all the pain and discomfort it was causing me. 

There was an indescribable sense of relief once the sores finally went away. 

Still, as distressing as my experience with herpangina was, I am apparently in the minority. 

Raffles Medical family physician Derek Li said adults who catch HFMD and herpangina are less likely to have severe symptoms compared with children.

Up to 80 per cent of adults and adolescents who test positive for these diseases are asymptomatic, he added, noting that as a result, precise data on the incidence of the diseases among these groups is not available.

Still, experts cited in an October report by parenting portal Romper suggested incidences of HFMD among adults have been increasing over the past decade, and that adults who encounter severe cases of the disease may have immune systems unfamiliar with the virus due to not having contracted it before.

A 2012 article on SingHealth’s resource portal HealthXchange.sg stated that adults and teenagers above 15 years old accounted for about one in 10 HFMD cases here.

Among the adults who contracted HFMD is local Mandopop singer JJ Lin, who said he contracted it in 2019 at the age of 38.

Dr Li said HFMD and herpangina are primarily spread by the faeco-oral route, similar to viral gastroenteritis, or through direct contact with respiratory droplets from an infected person. 

“The best way to avoid catching them is through good hand hygiene, and avoiding sharing food and drinks with someone who is unwell,” he said.

“If you are caring for an unwell child, it is a good idea to separate all clothing, towels and utensils so that one does not catch it inadvertently,” he added, noting that people should also regularly clean high-touch surfaces within the home.

Besides HFMD and herpangina, Fullerton Health’s Dr Lee noted that adults and children alike are prone to catching colds and stomach flu, or gastroenteritis. 

“Varicella zoster, or chicken pox, affects mainly young children, but adults who did not have previous infection can also be affected,” he added. 

So, to paraphrase an old police slogan, “low risk doesn’t mean no risk”. 

Even though I knew adults could catch diseases such as HFMD and herpangina, I guess I had always had the impression that I would be lucky enough to stay clear of them. 

But if there was one thing we should take away from the past three years of living under a pandemic, it would be that “lucky” is not enough to keep you safe from diseases. 

It is just like how aeroplane pre-flight safety announcements always remind passengers that in an emergency, you should put on your own oxygen mask before helping your children use theirs.

I have to bear in mind that I, too, need to take care of my own health and hygiene to ensure I am in good enough shape to take care of my children when they are unwell.